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  • 2000-2004  (17)
  • 1975-1979  (6,430)
  • 1960-1964  (4,869)
  • 1940-1944  (1,632)
  • 1860-1869  (423)
  • Inorganic Chemistry  (9,516)
  • Chemical Engineering  (3,082)
  • Atomic, Molecular and Optical Physics  (745)
  • Graad van aantasting
  • Heterocycles
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  • 1
    Electronic Resource
    Electronic Resource
    The Effect of the Carbon Ligand on the Reaction of Organozinc Reagents in the Synthesis of Substituted 2,5-Dihydrofurans: A Rare Example of An Uncatalysed Allylic-Substitution Reaction Involving Alkyl Zinc Halides (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1711-1718 
    Details
    ISSN: 1434-193X
    Keywords: Heterocycles ; Zinc ; Palladium ; Catalysts ; Sulfur ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Organozinc halides derived from Grignard reagents behave differently in their reaction with ethyl (±±)-(2RS,3SR)-tetrahydro-4-methylene-2-phenyl-3-(phenylsulfonyl)furan-3-carboxylate (3) according to the hybridisation of the carbon ligand. During the development of short multi-component reactions for the synthesis of diverse functionalized ethyl 2,5-dihydrofuran-3-carboxylates it was discovered that aryl and vinyl zinc halides undergo clean reaction with 3 in the presence of Pd(PPh3)4. In contrast, when alkyl zinc halides are reacted with 3 in the presence of Pd(PPh3)4, reductive desulfonation of 3 is observed. Remarkably, in the absence of a transition metal catalyst, the allylic substitution of 3 with alkyl zinc halides proceeds cleanly and in moderate to good yield.
    Additional Material: 2 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    1-Alkyl- and Azeto[1,2-a][1,5]benzodiazepine Derivatives in the Reaction of o-Phenylenediamine with 3-(Dimethylamino)propiophenones (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1973-1976 
    Details
    ISSN: 1434-193X
    Keywords: Benzodiazepines ; Heterocycles ; Azeto[1,2-a]-1,5-benzodiazepines ; Cyclizations ; Cycloadditions ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The reaction of o-phenylenediamine (4) with one, two or three equivalents of p-substituted 3-dimethylaminopropiophenone hydrochlorides 5a-e was studied. 4-Aryl-2,3-dihydro-1H-1,5-benzodiazepine derivatives 6a-e were obtained in good yields, along with the 1:2-adducts 7c-e and the unexpected 1:3-adducts rac-8c-e. The type of adduct formed is determined by the molar ratio of the reactants 4 and 5 and by the nature of the substituent in the para position of the propiophenone 5.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Reaction of 1,3-Disubstituted Acetone Derivatives with Pseudohalides: A Simple Approach to Spiro[4.4]nonane-Type Bis-Oxazolidines and -Imidazolidines (Bicyclic Carbamates, Thiocarbamates, Ureas, and Thioureas) (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 205-209 
    Details
    ISSN: 1434-193X
    Keywords: Heterocycles ; Carbohydrates ; Imidazolidines ; Oxazolidines ; Spiro compounds ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Prochiral 1,3-dihydroxyacetone forms racemic oxazolidine- and oxazoline-type spiro[4.4]nonanes upon reactions with potassium (thio)cyanate and cyanamide. In contrast, 1,3-diaminoacetone yields only the corresponding spiro-bisimidazolidinethione under similar conditions together with monocyclic by-products, but the spiro-bisimidazolidinone is accessible by reaction of 1,3-dichloroacetone with urea. The resolution of the racemic spiro-bisoxazolidinethione 2a was achieved by using brucine as the resolving agent.
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and Absolute Configuration of Hongoquercin A, an Antibacterial Sesquiterpene-Substituted Orsellinic Acid Isolated as a Fungal Metabolite (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 297-302 
    Details
    ISSN: 1434-193X
    Keywords: Antibiotics ; Configuration determination ; Heterocycles ; Hongoquercin A ; Terpenoids ; Total synthesis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---(±)-Hongoquercin A (1), the racemate of an antibacterial fungal metabolite, has been synthesized starting from geranylacetone (2) and ethyl orsellinate (ethyl 2,4-dihydroxy-6-methylbenzoate, 5). The structure (±)-1 has been confirmed by X-ray analysis of its ethyl ester (±)-10. Synthesis of the naturally occurring (+)-hongoquercin A from (-)-sclareol (11) established its configuration as depicted in 1.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Proximate, syn-Periplanar Bisdiazene Skeletons: Syntheses, Structures, Homoconjugate Reactivity and Photochemistry (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 763-785 
    Details
    ISSN: 1434-193X
    Keywords: Bisdiazenes ; Homoconjugation ; Photochemistry ; Heterocycles ; Diazenes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Rigid N=N/N=N (diazene/diazene) systems (F) consisting of more or less alkylated DBH and DBO chromophoric units (1, 2, X-ray structures), with very short π,π distances [d = 2.849 (1a, av.), 2.822 Å (2)] and almost perfect syn-periplanar π,π alignments [ω = 168.6 (1a), 174.2° (2)] as well as the more flexible, less “proximate” metathesis isomers (3a,c, 27a,c, d 〉4.6 Å, ω = 90-100°) have been synthesized. Homoconjugate π,π interaction (in 1, 2, not in 3, 27) is deduced from UV spectroscopic measurements [π → π* maxima at 239 (234) nm (sh, 260)], while PE analyses furnished only small interaction parameters (1a: 〈0.3 eV). The potential of the novel syn-periplanar N=N/N=N motif in 1 and 2 for the synthesis of somewhat exotic polyheterocycles has been explored by calculation (B3LYP) as well as experimentally: i.a. kinetically stabilized, all-cis-peralkylated tetrazolidines (38, 44) and perhydro-1,2,4,5-tetrazines (41, 47) have become accessible (i.a. via novel azomethine/diazene and azomethine/azomethine cycloadditions). In 1a with its unreactive DBO chromophoric subunits, in the “buttressed” derivatives 1b-d, as well as in the DBH/DBO combination 2, and likewise in more ‘distant’ 27 (differently from the analogous C=C/C=C and N=N/C=C systems), irrespective of the excitation conditions employed (light of λ ≥≥ 280, 254 nm, low temperature matrix irradiation, acetone sensitization) no [2+2]photocycloaddition was observed. Instead exclusively N2-elimination took place. It is argued that unproductive N=N/N=N photocycloaddition would have become observable through metathesis isomerization of the respective tetrazetidines.
    Additional Material: 9 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Proximate, syn-Periplanar Diazene/Diazene(di)oxy, Diazeneoxy/Diazene(di)oxy, and Diazenedioxy/Diazenedioxy Skeletons: Syntheses, [2+2]Photocycloadditions, Metathesis (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 787-806 
    Details
    ISSN: 1434-193X
    Keywords: Photochemistry ; Heterocycles ; Diazenes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Of two very proximate syn-periplanar bisdiazenes (1,2) mono-, di-, tri- and tetra-N-oxides were prepared, representing six combinations of the individual N=N/N=NO/ON=NO chromophores. According to DFT calculations (B3LYP/6-31G*), [2+2]photocycloaddition to the respective oxidized tetrazetidines is significantly to moderately endothermic. The metathesis isomerization of the oxidized tetrazetidines is generally highly exothermic and kinetically increasingly favorable with increasing oxidation state. In practice, four out of the six bichromophoric combinations undergo selectively, in competition with N2 elimination from a DBH unit (13) still partially, metathesis isomerization upon π → π* excitation (monochromatic 254 nm light). In the case of the syn-N=NO/N=NO combinations (5/6, 14), the photoaddition is thermally reversed. For a ON=NO/N=N combination (30), internal electron transfer is responsible for a complex reaction pattern. The preparative value of the metathesis reactions, though, is limited: The metathesis-derived bis[diazene mono(di)oxides] undergo relatively fast secondary photoreactions, while the tri(tetra)oxides undergo rapid thermal transformations. For the N=N/N=NO systems (12), of three potential pathways for its metathesis isomerization, the one that takes place via σ-symmetric intermediates (63, 64) is excluded by virtue of the retention of optical purity in the photometathesis of a highly enriched enantiomer [(-)-12]. Matrix irradiation experiments (12 K, IR control) with 12 result in the appearance of a kinetically highly labile transient. Supported by DFT calculations it is concluded that in the metathesis reactions, the respective tetrazetidine oxides (increasingly destabilized by interactions between oxygen lone pairs and NNσ* orbitals) function as vibrationally excited transients. That thermal reversion of these transients might be a general, nonproductive competition, is suggested by the experimental verification of a “reversed photometathesis” (51 → 15) and by the generally low rates in product formation upon irradiation. The question remains to be answered why in structurally analogous molecular skeletons, [2+2]photocycloaddition occurs in the C=C/N=N and variously oxidized N=N/N=N, and not, however, in the parent N=N/N=N combinations.
    Additional Material: 4 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of Ascididemine and an Isomer (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 849-855 
    Details
    ISSN: 1434-193X
    Keywords: Marine alkaloids ; Heterocycles ; Natural products ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Ascididemine (9H-quino[4,3,2-de][1,10]phenanthrolin-9-one) (1) and an isomer (9H-quino[4,3,2-de][1,7]phenanthrolin-9-one) (4) have been synthesized starting from 1,4-dimethoxyacridone (7). The acridone was converted into 1,4-dimethoxy-9-ethynylacridine (11) by a triflate coupling. The ethynylacridine was converted in one-pot into 3H-6-methoxypyrido[2,3,4-kl]acridine (15) by reaction with sodium diformylamide; the mechanism of this key transformation is discussed. Conversion into 6H-4-bromopyrido[2,3,4-kl]acridin-6-one (19) and 6H-pyrido[2,3,4-kl]acridin-6-one (17), followed by reaction of each of these under high pressure conditions with acrolein N,N-dimethylhydrazone, gave ascididemine and its isomer, respectively.
    Additional Material: 2 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Polyol Peptidomimetics (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1113-1120 
    Details
    ISSN: 1434-193X
    Keywords: Peptidomimetics ; Reverse turn mimetics ; Glycomimetics ; Heterocycles ; Lactams ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -D-Glucurono-3,6-lactone and L-cysteine combine in a highly stereoselective manner to give the 7,5-bicyclic thiazolidinlactam 2. The α-hydroxy group of the D-glucurono-3,6-lactone was exchanged for an amino function (to give 13) and, after condensation with L-cysteine methyl ester, the polyol dipeptide 7 was obtained. Peptide couplings proceed without the need to protect the three secondary hydroxy groups of the seven-membered ring. The amino group of 7 was deprotected and selectively elongated to the pseudo-tripeptide 16. The depsipeptide 17 was obtained by condensation of Boc-Ala-OH with the polyol 2. Elongation at the carboxy terminus yielded 19 and 20. The bicyclic scaffold populates a well-defined solution conformation; the hydroxy groups mimic the side chains of hydrophilic amino acids and can be further functionalized.
    Additional Material: 1 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Proximate, syn-Periplanar, Rigid Imine(Nitrone)/Ene-, and Diazene(Diazeneoxy)/Ene Systems: Syntheses, Homoconjugate Reactivity and Photochemistry (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 743-762 
    Details
    ISSN: 1434-193X
    Keywords: Chromophores ; Photochemistry ; Heterocycles ; Diazenes ; Imines ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The chances for intramolecular imine/ene (→ azetidines), diazene/ene (→ 1,2-diazetidines), diazeneoxy/ene (→ 1,2-diazetidine oxides) and diazenedioxiene (→ 1,2-diazetidine dioxides) [2+2]photocycloadditions and for the isolation of the respective photoproducts, have been probed with specifically designed substrates. Upon direct or sensitized excitation, [2+2]cycloaddition was found to be the exclusive or at least dominant chemical process for the C=N/C=C, N=N/C=C and ON=N(O)/C=C systems featuring very small π,π-distances of 2.8-3.0 Å and large π,π-interorbital angles of 160-170° (7 → 51, 17 → 55, 33 → 58 (competing N2 elimination), 22 → 62). This is not the case, however, in ON=NO/C=C (23, where electron transfer is a possibility), or in the more flexible, less “proximate” C=N/C=N (57) and C=NO/C=N (63) systems (π,π-distances of 〉3.8 Å). While the corseted 1,2-diazetidine photoadducts (55, 58) proved to be thermally stable, their N-oxides (62, 65) were thermally too labile to be directly observable above -65 °C. For the latter's only fleeting existence, electronic rather than strain effects are held responsible (B3LYP/6-31G* calculations). Very facile C=NO/C=C (12 → 13) and N=NO/C=C (22 → 24) [3+2]cycloadditions, homoconjugate addition of H2 and of dienophiles ([2+2+2]) to the diazene/ene 17 (→ 39, 41, 45) are manifestations of “proximity” in these bichromophoric skeletons.
    Additional Material: 1 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Oxidative Heterocyclization of 2-Alkynylbenzaldehydes with 1,2-Phenylenediamine (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1433-1441 
    Details
    ISSN: 1434-193X
    Keywords: Alkynes ; Annelation reactions ; Carbonyl compounds ; Heterocycles ; Polycycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Upon condensation of ortho-phenylenediamine (2) with ortho-alkynylbenzaldehydes in nitrobenzene, oxidative cyclizations are observed, which result in benzimidazo[2,1-a]isoquinolines (8) or isoindolo[2,1-a]quinoxalines (9) depending on the influence of additional substituents at the alkyne.
    Additional Material: 1 Ill.
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  • 11
    Electronic Resource
    Electronic Resource
    Synthesis of 5-Methylbenzo[b]thieno[2,3-c]isoquinolines and5-Methylbenzo[b]seleno[2,3-c]isoquinolines (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1353-1357 
    Details
    ISSN: 1434-193X
    Keywords: Heterocycles ; Rearrangements ; C-C coupling ; C-C coupling ; Cyclizations ; Isoquinolines ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -5-Methylbenzo[b]thieno[2,3-c]isoquinolines and 5-methylbenzo[b]seleno[2,3-c]isoquinolines 11b,c have been prepared by Bischler-Napieralski cyclization of 2-acetamido-3-phenylbenzo[b]heteroarenes.
    Additional Material: 4 Tab.
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  • 12
    Electronic Resource
    Electronic Resource
    Calculated Properties and Ring-Chain Rearrangements of Triphosphirane (P3H3) (2000)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 103-112 
    Details
    ISSN: 1434-1948
    Keywords: Ab initio calculations ; Ionization potentials ; Phosphorus ; Heterocycles ; Small ring systems ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio quantum chemical calculations have been used to explore the P3H3 potential energy surface focussing on the ring-chain rearrangements of the three-membered ring in (PH)3 (1), the parent triphosphirane. Relative energies between stationary points were estimated using the QCISD(T)/6-311G(d,p) method based on MP2/6-31G(d,p) geometries and corrected for zero-point contributions. Ring strain, proton affinities, ionization and excitation energies and heats of formation have been evaluated using larger basis sets, e.g. 6-311++G(3df,2p). The cyclic trans-triphosphirane (1a) is the most stable P3H3 isomer and lies about 40 kJ/mol below the open-chain phosphanyldi-phosphene (H2P-P=PH). The decrease of ring strain in three-membered rings when CH2 is replaced by PH is confirmed. Triphosphirane 1a is a virtually strain-free ring and even gains some stabilization relative to three separate P-P single bonds. The reduced ring strain also helps diminish the phosphorus inversion barrier to 224 kJ/mol compared to the monocyclic isomers of (CH2)(PH)2 and (CH2)2(PH). Compound 1a follows a pure ring-opening or a 1,2-hydrogen shift rather than a combined motion pathway, in fundamental contrast with corresponding processes of diphosphirane and phosphirane. This is due to the existence of an open-chain P3H3 phosphorane intermediate stabilized by allylic conjugation. The pericyclic ring-opening of 1a is the most favored process but the energy barrier in the gas phase is about 180 kJ/mol high. Electron density is largely delocalized within the three-membered P3 ring not only in the C3v-symmetric 1b (all-cis) but also in 1a (Cs). The proton affinity of 1a is similar to that of PH3. The proton affinities decrease with n in cyclo-(CH3)3 -n(PH)n and their values were obtained: PA(1a) = 777 ±10, PA(diphosphirane) = 799 ±10 and PA(phosphirane) = 802 ±10 kJ/mol. Heats of formation are evaluated as follows (ΔH°f0 at 0 K in kJ/mol): 1a, 70 ±10; cyclo-(PH)2(PH2)+ (protonated 1a), 821 ±10; diphosphirane, 85 ±10; cyclo-(CH2)(PH)(PH2)+ (protonated diphosphirane), 814 ±10; phosphirane, 86 ±10; and protonated phosphirane, 812 ±10 kJ/mol. All P rings remain cyclic following ionization to the radical cations. Adiabatic ionization energies (IEa) are estimated as: 1a and diphosphirane, 9.3 ±0.3 eV and phosphirane 9.5 ±0.3 eV. The first UV absorption band shifts toward the longer wavelength region on going from phosphirane to 1a. The GIAO/B3LYP computed magnetic shieldings for 1a and related molecules reveal a clear relationship between the narrow bond angles in the rings and their unusually strong magnetic shielding. The similarity of the predicted 31P-NMR signals in 1a and its heteroanalog diphosphirane, (CH2)(PH)2, can be rationalized in terms of a compensation of the carbon-substituent effect (downfield shift) and the bond-bending effect imposed by the ring (upfield shift).
    Additional Material: 5 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    Novel Fluorescent Dyes by the Extension of the Core of Perylenetetracarboxylic Bisimides (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 365-380 
    Details
    ISSN: 1434-193X
    Keywords: Fluorescent dyes ; Perylenes ; Heterocycles ; NIR dyes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Core-extended perylenetetracarboxylic bisimides were prepared by Diels-Alder reaction followed by reduction, or by nitration followed by cyclisation. Highly fluorescent dyes were obtained with absorption regions from the visible to the NIR. Applications for solar energy harvesting, and quantum counters were suggested.
    Additional Material: 9 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    Preparation and Characterization of Cyanovinyl-Substituted 2-Aminothiophenes and 2-Aminothiazoles and Some of Their Heterooligomers (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1327-1334 
    Details
    ISSN: 1434-193X
    Keywords: Heterocycles ; Thiophenes ; Solvatochromism ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reaction of 2,2-dicyanoethenyl- and 1,2,2-tricyanoethenyl-substituted bromoalkanes, bromomethyl benzenes, thiophenes, and furans 19-22 with 3-aminothioacrylamides and their 2-azaanalogues 23 and 24 gives a series of 5-dicyanoethenyl- and 5-tricyanoethenyl-substituted 2-aminothiophenes, 2-aminothiazoles and their (hetero)benzologous analogues 25-32. The solvatochromism, which is a characteristic feature of these donor-acceptor substituted heterocyclic compounds, was studied in detail and correlated with the Kamlet-Taft solvent parameters.
    Additional Material: 4 Tab.
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  • 15
    Electronic Resource
    Electronic Resource
    Nucleophilic Substitution of 4H-Imidazoles - A Key Step in the Synthesis of Fused Imidazoles and New Chromophores (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1661-1668 
    Details
    ISSN: 1434-193X
    Keywords: Imidazoles ; Nucleophilic substitutions ; Fulvenes ; Pseudo-azulenes ; Heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The electrophilic properties of the 4H-imidazoles 1 and their protonated derivatives 2 permit the introduction of nucleophilic building blocks, as illustrated by reactions of 1 with selected amines. Depending on the nature of the amine and the substituents R1 on the heterocycle 1, single (3) or double (4) transamination is observed. The 1H-NMR spectra of the products, as well as X-ray structure analyses of compounds 3f and 4c, confirm that the residues at the 4- and/or 5-positions of 1 are exchanged. The tautomerism between 3e-h and 3e′-h′ seems to be central to the chemistry of these mixed substituted derivatives. Using orthoesters and acetophenone dimethylacetal as cyclization partners, the imidazo[4,5-d]imidazoles 5 and the 4H-imidazo[4,5-b]pyrazines 6 are obtained, respectively. Reduction of 3e with Zn/HCl or H2S leads to the air-sensitive, strongly fluorescent leuco compounds 8. Quenching of 8 by addition of aromatic aldehydes results in a condensation reaction and, coupled with the subsequent redox disproportionation, this conversion constitutes an alternative route to imidazo[4,5-d]imidazoles of type 11. The unexpected reaction of 3e-h with Lawesson's reagent allows synthesis of the 6-azapentafulvenes 14. The relevant spectral data show 14 to be members of a new chromophoric system, in which an electron-rich five-membered ring is coupled with an electron-deficient ring.
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  • 16
    Electronic Resource
    Electronic Resource
    A Simple Stereoselective Synthesis of Enantiopure 2-Substituted Pyrrolidines and Piperidines from Chiral (R)-Phenylglycinol-Derived Bicyclic 1,3-Oxazolidines (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1719-1726 
    Details
    ISSN: 1434-193X
    Keywords: Asymmetric synthesis ; Nitrogen heterocycles ; Heterocycles ; Pyrrolidines ; Piperidines ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Chiral, nonracemic 2-substituted pyrrolidines and piperidines were prepared in high ee and moderate to good chemical yields in three steps from (R)-phenylglycinol and γ- or δ-chloroketones. The key step of the synthesis was the stereoselective reductive ring-opening of chiral bicyclic 1,3-oxazolidines prepared by condensation of (R)-phenylglycinol and the corresponding ketones.
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  • 17
    Electronic Resource
    Electronic Resource
    Substituted Tetraoxa[8]circulenes - New Members of the Liquid Crystal Family (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1637-1640 
    Details
    ISSN: 1434-193X
    Keywords: Circulenes ; Heterocycles ; Liquid crystals ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A general method for the synthesis of substituted tetraoxa[8]circulenes based on alkylation of 2,3-bis(bromomethyl)-1,4-dimethoxybenzene with acetylides is reported. Four of the compounds shows LC behavior, and the tetraoxa[8]circulenes are thus new candidates for discotic mesogens.
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  • 18
    Electronic Resource
    Electronic Resource
    Synthesen von Aminomethylen-γ-halogenacetessigsäurederivaten und deren Ringschlußreaktionen zu 3-Hydroxypyrrolen, Pyrido[1,2-a]pyrimidonen bzw. 4-Chinolonen β,β-Diacyl-enamine und-enole, 5. Mitt. (1979)
    Springer
    Monatshefte für Chemie 110 (1979), S. 1387-1405 
    Details
    ISSN: 1434-4475
    Keywords: Enamines, synthesis ; Heterocycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Condensation of alkyl γ-haloacetoacetates (or γ-chloroacetoacetanilide) with triethoxymethane and primary (hetero)aromatic amines gives in a one step synthesis under mild conditions new β,β-diacyl-enamines (2 a-m, 3 a-d). In contrast, the N-alkylsubstituted derivatives could be synthesized only in a two step procedurevia the enolethers6 a, b. According to their ir-specra, most of the aminomethylene-γ-haloacetoacetic acid derivatives are stereochemically fixed either in theE- orZ-form. The pmr-spectra, however, show that they exist as mixtures of at least two isomers in solution. With KOH or sodium acetate, a ring closure to 3-hydroxy-pyrroles (8, 9) could be achieved whereas with pyridine only quarternary pyridinium salts (11) are formed. Acidic (orLewis acidic) condensing agents leave the chloroacetyl group unaffected and give either free carboxylic acids (2 p-r) pyrido-[1,2-a]pyrimidones (12) or 4-quinolones (13), depending on the type of the molecule and the reaction temperatures employed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00938295
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  • 19
    Electronic Resource
    Electronic Resource
    Bicyclo[2.1.1]hexane aus Tricyclo[3.1.0.02,6]hexanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2012-2021 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bicyclo[2.1.1]hexanes from Tricyclo[3.1.0.02,6]hexanesThe novel tricyclo[3.1.0.02,6]hexane derivatives 3 and 4, being fused with a fife- and a sixmembered ring respectively, are prepared from benzvalene in several steps. They and their lower homologues 1 and 2, having a three- and fourmembered ring respectively, add thiophenol under conditions of a radical reaction to form smoothly one cyclobutylphenyl thioether (16-19) in each case. Therefrom the parent hydrocarbons (5-8) which contain the bicyclo[2.1.1]hexane skeleton, are obtained by means of reduction with lithium in ethylamine.
    Notes: Ausgehend von Benzvalen werden in mehreren Stufen die neuen Tricyclo[3.1.0.02,6]hexan-Derivate 3 und 4 mit anelliertem Fünf- bzw. Sechsring dargestellt. Sie und ihre niedrigeren Homologen 1 und 2 mit Drei- bzw. Vierring nehmen unter Bedingungen einer Radikalreaktion Thiophenol auf, wobei glatt jeweils ein Cyclobutylphenylthioether (16-19) gebildet wird. Mit Lithium in Ethylamin sind aus 16-19 die tricyclischen Stammkohlenwasserstoffe mit dem Bicyclo[2.1.1 ]hexan-Gerüst (5-8) erhältlich.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120611
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  • 20
    Electronic Resource
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    Der Einfluß anellierter Ringe auf die 13C-NMR-chemischen Verschiebungen von Tricyclo[3.1.0.02,6]hexan- und Bicyclo[2.1.1]hexan-Derivaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2022-2027 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Influence of Fused Rings on the 13C Shieldings of Tricyclo[3.1.0.02,6]hexane and Bicyclo[2.1.1]hexane DerivativesThe 13C shieldings of the tricyclo[3.1.0.02,6]hexane derivatives 2-5 and of the bicyclo[2.1.1]-hexane derivatives 7-10 and 12-15 show a strong dependence on the size of the fused rings. Especially the γ-anti-effects, which cause downfield shifts, and the γ-syn-effects of these rings, which result in upfield shifts, are subject to unexpected variations.
    Notes: Die 13C-chemischen Verschiebungen der Tricyclo[3.1.0.02,6]hexan-Derivate 2-5 und der Bicyclo[2.1.1]hexan-Derivate 7-10 und 12-15 zeigen eine starke Abhängigkeit von der Größe der anellierten Ringe. Insbesondere die nach tieferem Feld gerichteten γ-anti-Effekte und die nach höherem Feld gerichteten γ-syn-Effekte dieser Ringe unterliegen unerwarteten Variationen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120612
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  • 21
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    Reaktionen an Indolderivaten, XXXIX. Stereoselektive Totalsynthese von Eburnamonin, Eburnamin und Eburnamenin (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1902-1912 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXIX. A Stereoselective Synthesis of Eburnamonine, Eburnamine, and EburnamenineStudies on the five-membered lactams 1 and 2 disclose a stereoselective access to eburnamonin-19-one (22). This substance is easily transformed into eburnamonine (25), eburnamine (30), and eburnamenine.
    Notes: Das Studium der 5-Ring-Lactame 1 und 2 eröffnet einen stereoselektiven Zugang zum Eburnamonin-19-on (22). Diese Substanz läßt sich auf einfache Weise in die drei Alkaloide Eburnamonin (25), Eburnamin (30) und Ehurnamenin überführen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120541
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  • 22
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    En-Reaktionen mit Cyanthioformaniliden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1916-1918 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ene Reactions with CyanothioformanilidesCyanothioformanilides 3 react with methylenecyclohexane (1) and β-pinene (2) in boiling toluene to yield the adducts 4 and 5, resp., according to the mechanistic scheme of an ene reaction.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120543
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  • 23
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    Masthead (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120601
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  • 24
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    Synthesis of new chiral hydrocarbons (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1919-1922 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthese von neuen chiralen KohlenwasserstoffenUnsymmetrisches Anheften einer aliphatischen (CH2)n-Brücke an ein an sich achirales aromatisches System führt zu starren chiralen Kohlenwasserstoffen des Typs 2; die Enantiomeren 2 a konnten mit Hilfe von TAPA angereichert werden. Die Racemisierungskinetik wurde polarimetrisch bestimmt: ΔG≠20 = 93.6 kJ · mol-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120544
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  • 25
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    Pheromone, XXIV. Notiz zur Synthese der Sexuallockstoffe (Z)-7-Dodecenylacetat und (Z)-7-Tetradecenylacetat (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1923-1925 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pheromones, XXIV. Synthesis of the Sex Attractants (Z)-7-Dodecenyl Acetate and (Z)-7-Tetradecenyl Acetate(Z)-7-Dodecenyl acetate, the female sex pheromone of the Noctuid moth Trichoplusia ni, and (Z)-7-tetradecenyl acetate, the sex attractant of Amathes c-nigrum (Lepidoptera), are prepared by stereoselective Wittig olefination using the „silazide“ -technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120545
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  • 26
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    Dynamische NMR- Untersuchungen an (Di-tert-butylamino)arsanen und -stibanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1927-1933 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dynamic NMR Studies of (Di-tert-butylamino)arsanes and -stibanesThe reaction of LiN[C(CH3)3]2 with AsX3 (X = F → Br). (CH3)3CAsCl2 and SbCl3 yields the di-tert-butylamino)arsanes 1a-c, 2 and dichloro(di-tert-butylamino)stibane (1d). LiN(CR3)-(SiR3), R=CH3and 1a-c form 3. The El — N torsional barriers of these compounds (measured by temperature dependent 1H-NMR spectroscopy) are compared with those of the (diisopropylamino)arsanes 4. and other related compounds. The influence of the N and El ligands with respect to the El — N torsional barrier is discussed. Thermolysis of 3c affords the di-tert-butylaminyl radical.
    Notes: Durch Umsetzung von LiN[C(CH3)3]2 mit AsX3 (X = F → Br), (CH3)3CAsCl2 und SbCl3 erhält man die (Di-tert-butylamino)arsane 1a-c und 2 sowie Dichlor(di-tert-butylamino)stiban reagieren mit LiN(CR3)(SiR3), R=CH3 zu 3 weiter. Die durch temperaturabhängige 1 H-NMR-Messungen ermittelten El- N-Rotationsbarrieren dieser Verbindungen werden hinsichtlich des Ligandeneinflusses am N- El - Atom mit den (Diisopropylamino)arsanen 4. und verwandten Molekülen verglichen. 3c. ergibt bei der Thermolyse das Di-tert-butylaminyl-Radikal.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120602
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  • 27
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    Isocyanidkomplexe, I. Isocyanphosphane und -arsane als Komplexliganden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1934-1940 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isocyanide Complexes, I. Isocyanophosphanes and -arsanes as Ligands of ComplexesThe reaction of K[CpMn(CO)2CN] (Cp = η-C5H5) with PR2Cl (R=C2H5, OC2H5, C6H5) and As(C6H5)2Cl yields the complexes CpMn(CO)2CNPR2 (3a - c) and CpMn(CO)2CNAsPh2 (3d) with C-coordinated isocyanophosphanes and -arsanes. In the reaction of CpMn(CO)2CNPPh2 with CpMn(CO)2 THF or of K[CpMn(CO)2CN] with CpMn(CO)2PPh2Cl a complex with an isocyanophosphane bridge, {CpMn(CO)2}2(CNPPh2) (4), is obtained. The IR, NMR, and mass spectra of the compounds 3a-d and 4 are discussed.
    Notes: Bei der Umsetzung von K[CpMn(CO)2CN] (Cp = η-C5H5) mit PR2Cl (R=C2H5, OC2H5, C6H5) und As(C6H5)2Cl entstehen die Komplexe CpMn(CO)2CNPR2 (3 a - c) und CpMn(CO)2CNAsPh2 (3d) mit C-gebundenen Isocyanphosphanen und -arsanen. Durch Reaktion von CpMn(CO)2CNPPh2 (3c) mit CpMn(CO)2 THF bzw. von K[CpMn(CO)2]CN mit CpMn(CO)2PPh2Cl erhält man den Komplex {CpMn(CO)2}2(CNPPh2) (4) mit einer Isocyanphosphan-Brücke. Die IR-, NMR- und Massenspektren der Verbindungen 3a-d und 4 werden diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120603
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  • 28
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    Barrieren der behinderten Rotation um die N-glycosidische Bindung, IV. 1-(β-D-Ribofuranosyl)isocyanursäuren (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1941-1947 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Barriers to Hindered Rotation Around the N-Glycosidic Bond, IV. 1-(βD-Ribofuranosyl) isocyanuric AcidsThe β-ribofuranosyl nucleosides 5a-c and 6b, c are synthesized. The temperature dependency of the 1H- and 13C-NMR spectra can only be interpreted as hindered rotation around the N-glycosidic bond2). The Gibbs activation energies (43-46 kJmol-1) are independent of acetylation of the OH groups of the furanose ring or restriction of its flexibility through formation of a 2′,3′-isopropylidene derivative, and are considerably lower than the corresponding data (about 69 kJmol-1) of the glucopyranosyl nucleosides 7b, c. The activation entropies are small. The results are interpreted.
    Notes: Es werden Synthesen der β-Ribofuranosylnucleoside 5a-c und 6b, c beschrieben. Die Temperaturabhängigkeiten der 1H-und 13C-NMR-Spektren lassen sich nur als Folge behinderter Rotation um die N-glycosidische Bindung deuten2) Die Gibbsschen Aktivierungsenergien (43-46 kJmol-1) sind unabhängig von einer Acetylierung der OH-Gruppen des Furanoseringes oder einer Einschränkung von dessen Flexibilität durch Bildung eines 2′,3′-Isopropylidenderivates und liegen erheblich tiefer als die entsprechenden Werte (um 69 kJmol-1) der Glucopyranosylnucleoside 7b, c. Die Aktivierungsentropien sind gering. Die Befunde werden gedeutet.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120604
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  • 29
    Electronic Resource
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    Synthesen von α-Bromisothiocyanaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1948-1955 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of α-BromoisothiocyanatesSecondary isothiocyanates (1j-q) and primary isothiocyanates R—CH2 - NCS with an activating group R (1f, g) react with N-bromosuccinimide (NBS) to form α-bromoisothiocyanates 2 in high yields. The not activated primary isothiocyanate 1c slowly forms the stable α,α-dibromoisothiocyanate 10. In the presence of β-hydrogens some of the α-bromoisothiocyanates 2 eliminate HBr spontaneously, and secondary products may be formed. The α-bromination of isothiocyanates is a radical reaction following a Goldfinger mechanism.
    Notes: Sekundäre Isothiocyanate (1j-q) und primäre Isothiocyanate R-CH2 - NCS mit einer aktivierenden Gruppe R (1f, g) lassen sich mit N-Bromsuccinimid (NBS) in hohen Ausbeuten zu den α-Bromisothiocyanaten 2 bromieren. Das nicht aktivierte Isothiocyanat 1c reagiert langsam zum stabilen α,α-Dibromisothiocyanat 10. Bei Anwesenheit von β-Wasserstoffatomen spalten die α-Bromisothiocyanate 2 zum Teil spontan HBr ab, und es entstehen Folgeprodukte. Die α-Bromierung der Isothiocyanate erfolgt radikalisch nach einem Goldfinger-Mechanismus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120605
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  • 30
    Electronic Resource
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    Reaktionen von α-Bromisothiocyanaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1956-1972 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of α-Bromoisothiocyanatesα-Bromoisothiocyanates 11.2) with a hydrogen in β-position eliminate HBr to form vinyl isothiocyanates (products 2, 3, 5). Water hydrolyzes 1 to carbonyl compounds (7a). Hard nucleophiles attack 1 at the α-C-atom with substitution of bromine (products 8-12), but soft nucleophiles add to the C-atom of the isothiocyanato group (products 14, 19). Compounds 1 react with bifunctional nucleophiles to heterocycles (e. g. products 16, 21). The chemical properties of the classes of compounds, part of which are new, e. g. the geminal diisothiocyanates 12, are examined. The alkylidene thiourea 14f shows hindered rotation around the amide-CS—N bond (ΔG≠394 = 82.8 kJmol-1) and around the C=N double bond (ΔG≠244 = 52.9 kJmol-1).
    Notes: α-Bromisothiocyanate 1 mit einem β-Wasserstoff spalten HBr zu Vinylisothiocyanaten ab (Produkte 2, 3, 5). Wasser hydrolysiert 1 zu Carbonylverbindungen (7a). Harte Nucleophile greifen 1 am α-C-Atom unter Substitution des Broms an (Produkte 8-12), weiche Nucleophile lagern sich dagegen an das C-Atom der Isothiocyanatgruppe an (Produkte 14, 19). Verbindungen 1 reagieren mit bifunktionellen Nucleophilen zu Heterocyclen (z. B. Produkte 16, 21). Die chemischen Eigenschaften der z. T. neuen Verbindungsklassen, z. B. der geminalen Diisothiocyanate 12, werden untersucht. Der Alkylidenthioharnstoff 14f zeigt behinderte Rotation um die Amid Cs—N-Bindung (ΔG≠394 = 82.8 kJmol-1) und um die C=N-Doppelbindung (ΔG≠244 = 52.9 kJmol-1).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120606
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    Die Kristallstruktur von (η3-Allyl)dicarbonyl(triphenyl-phosphan)cobalt und sein dynamisches Verhalten in Lösung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1973-1980 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure and the Fluxional Behaviour in Solution of (η3-Allyl)dicarbonyl(triphenyl-phosphane)cobalt[Co(η3-C3H5)(CO)2PPh3] (1) crystallizes in the triclinic space group P1 with two molecules per unit cell. The crystal structure was solved and refined with X-ray diffraction data (R = 0.031, 2046 observed reflections). The cobalt atom has a distorted square pyramidal coordination with the formally bidentate η3-allyl ligand, the phosphane, and one carbonyl in the basal positions. According to the NMR spectra at temperatures down to 135 K, in solution there exists a fluxional equilibrium with the η3-allyl ligand oscillating between two enantiomeric positions.
    Notes: [Co(η3-C3H5)(CO)2PPh3] (1) kristallisiert triklin in der Raumgruppe P1 mit zwei Molekülen pro Elementarzelle. Die Kristallstruktur wurde mit Röntgenbeugungsdaten ermittelt und verfeinert (R = 0.031, 2046 beobachtete Reflexe). Das Cobaltatom ist verzerrt quadratisch-pyramidal koordiniert, mit dem formal zweizähnigen η3-Allylliganden, dem Phosphan und einem Carbonylliganden in der Pyramidenbasis. Nach den NMR-Spektren bei Temperaturen hinab bis 135 K liegt in Lösung ein dynamisches Gleichgewicht vor, bei dem die η3-Allylgruppe zwischen zwei enantiomeren Positionen fluktuiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120607
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  • 32
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    Hydrazidine, III. Synthese von 1,2,4,5-Tetrazino [3,2-a]isoindolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1981-1990 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrazidines, III. Synthesis of 1,2,4,5-Tetrazino[3,2-a]isoindolesReaction of acetohydrazide hydrazone hydrochloride (1) with phthalaldehydic acid (5) yields 3-methyl-1,10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (8), which affords 1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9a) by mild oxidation. 9a is also obtained by the reaction of 1 with the phthalic acid derivatives 6a, 7a, and 7b. Starting with 9a, the 1,2,4,5-tetrazino[3,2-a]isoindoles 12-15 are synthesized. Interaction of 1 and 3-nitrophthalic anhydride (6b) yields two isomeric nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-ones (9b,c). Oxidation of 9a or b with KMnO4 in methanol affords the 1,2,4,5-tetrazino 17a, b. Mild Oxidation of 9a with KMnO4 in water/trichloromethane yields a dimer (20), which dissociates in nitromethane into the radical 19.
    Notes: Durch Reaktion von Acetohydrazid-hydrazon-hydrochlorid (1) mit Phthaladehydsäure (5) wird 3-Methyl-1, 10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (8) erhalten das durch milde Oxidation in 3-Methyl-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (9a) übergeführt wird. 9a entsteht auch aus 1 und den Phthalsäurederivaten 6a, 7a und 7b. Ausgehend von 9a werden die 1,2,4,5-Tetrazino[3,2-a]isoindole 12-15 synthetisiert. Aus 1 und 3-Nitrophthalsäureanhydrid (6b) werden zwei isomere Nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9b, c) erhalten. Oxidation von 9a oder b mit KMnO 4 in Methanol ergibt die 1,2,4,5-Tetrazine 17a, b. Vorsichtige Oxidation von 9a mit KmnO4 in Wasser/Chloroform ergibt ein Dimeres (20), das in Nitromethan in das Radikal 19 dissoziiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120608
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    Stereochemie der Metall-Metall-Bindung. Strukturvergleich der Komplexe Cr2(CO)8(AsMe2)2, CrFe(CO)7(AsMe2)2 und Fe2(CO)6(AsMe2)2 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1991-1998 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Metal-Metal Bond. Structural Comparison of the Complexes Cr2(CO)8(AsMe2)2, CrFe(CO)7(AsMe2)2, and Fe2(CO)6(AsMe2)2The molecular structures of the new complexes CFer2(CO)8(AsMe2)2 (1) and CrFe(CO)7(AsMe2)2 (2) were determined crystallographically, that of Fe2(CO)6(AsMe2)2 (3) was redetermined. In all three compounds the metal-metal bond lengths are determined by the goemetrical requirements of the ligands. The fact that the M2As2 framework is planar in 1 and strongly folded in 2 and 3 can also be explained by the steric demands of the ligands. Aspects of the fluxionality of these complexes are discussed.
    Notes: Die Molekülstrukturen der neuen Komplexe Cr2(CO)8(AsMe2)2 (1) und CrFe(CO)7(AsMe2)2 (2) wurden kristallographisch ermittelt, die von Fe2(CO)6(AsMe2)2 (3) wurde neu bestimmt. In allen drei Verbindungen sind die Metall-Metall-Bindungslängen durch die geometrischen Ansprüche der Liganden festgelegt. Auch die Tatsache, daß das M2As2-Gerüst in 1 eben und in 2 und 3 jeweils stark gefaltet ist, läßt sich auf den Raumbedarf der Liganden zurückführen. Aspekte der Fluktuation dieser Komplexe werden diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120609
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    Electronic Resource
    Untersuchungen an Stoffwechselprodukten von Mikroorganismen, XX. Die Konstitutionen der Pigmente vom Flexirubin-Typ aus Cytophaga johnsonae Cyjl (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1999-2011 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Metabolites of Microorganisms, XX. The Structures of the Flexirubin-type Pigments from Cytophaga johnsonae CyjlCytophaga johnsonae Cy jl produces more than 25 different flexirubin-type pigments (2 a-h, 3 a-h, 4 a-h, 5) besides lower concentrations of carotenoids. These pigments could be separated using HPLC. Their structures have been elucidated. 5 is the first known member in this class of bacterial pigments containing two chlorine atoms.
    Notes: Das Gleitende Bakterium Cytophaga johnsonae Cy jl produziert neben wenig Carotinoiden mehr als 25 verschiedene Pigmente vom Flexirubin-Typ (2a-h, 3a-h, 4a-h, 5), deren Trennung u.a. durch Hochdruckflüssigchromatographie gelang. Über die Konstitutionen dieser Pigmente wird berichtet. Mit 5 wurde erstmals in dieser Verbindungsklasse ein dichlorhaltiges Pigment aufgefunden.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120610
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  • 35
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150201
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  • 36
    Electronic Resource
    Electronic Resource
    Use of the overlap multipole expansion for approximating molecular electrostatic potentials (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 121-129 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular electrostatic potentials computed by the overlap-multipole-expansion procedure (OMTP) are compared to exact electrostatic potentials computed with the same Gaussian basis set, for different molecular species. It is shown that at distances of the molecule larger than 2.2 Å, the OMTP values compared to those of the exact ones are within an error of 0.5 kcal/mol. This error decreases with increasing distance. For distances below this limit the OMTP potentials may be used as a first indication of the trends of the molecule, provided the values to compare are not too close.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150112
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  • 37
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    Electronic Resource
    Quantum chemistry by random walk: H4 square (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 109-120 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The random-walk method of solving the Schrödinger equation is applied to the 1B1g and 1B2g states of the H4 square with side length 2.4 a.u. The results provide an independent check of the accuracy of prior variational calculations for these states. With node structures for the 1B1g state taken from a variational calculation with a single-zeta basis set and taken in the simplest form meeting symmetry requirements, the calculated energies are lower than the expectation value of the energy for the single-zeta basis set but not as low as the expectation value for an optimized-exponent double-zeta basis set with polarization terms. Comparisons of results give no suggestion of a barrier height lower than ∼120 kcal/mol for passage through the square configuration in the exchange reaction H2 + D2 → 2HD. For the 1B2g state with node structure in the simplest form meeting symmetry requirements the calculated energy is ∼65 kcal/mol lower than the expectation value of the energy for variational calculations with a double-zeta basis set.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150111
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  • 38
    Electronic Resource
    Electronic Resource
    First-order properties and the Hellmann-Feynman theorem in the case of a limited CI wave function (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 135-145 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two distinct approaches to the calculation of first-order properties with a limited CI wave function are discussed. One is based on the Hellmann-Feynman theorem and the other on the direct evaluation of the total energy derivative at zero perturbation. Corrections to the Hellmann-Feynman expectation value are given for the CI wave function consisting of a single determinant reference state and all single and double replacements of this. These corrections are the extended Brillouin matrix elements and involve interactions between the zeroth-order wave function and triply substituted configurations. The usefulness of these matrix elements for the generation of MC SCF orbitals and for the calculation of cluster corrections to the wave function is briefly discussed. The formulas for the Brillouin matrix elements expressed in terms of one- and two-electron integrals have been automatically generated using the syntax of the algebraic program SCHOONSCHIP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150202
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  • 39
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150301
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  • 40
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    Electronic Resource
    Formal theory of effective π-electron hamiltoniansWork carried out under the auspices of the United States Department of Energy. (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 207-242 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We argue that the goal of developing a satisfactory general formalism for the justification of effective π-electron Hamiltonians, as well as for ab initio calculation of their parameters (α, β, and γ), has now been achieved. The need for a fully linked many-body formalism is emphasized; this feature requires a Rayleigh-Schrödinger (RS) type of degenerate perturbation theory. A number of apparently different degenerate RS perturbation formalisms are reviewed. Most of these formalisms are actually identical term-by-term, when their RS expansions are worked out explicitly; the formal relations that prove their complete equivalence are presented and discussed. One of these formalisms, a version developed by the author for related open-shell problems in nuclear physics, is shown to be most convenient for many-body applications. This is owing to the relatively simple and transparent nature of its general algebraic structure, which facilitates partial summation to infinite order. A simple and concise derivation is presented for the algebraic features of this preferred formalism, and its many-body (linked cluster) aspects are briefly discussed. The recent development of a nonperturbative (coupled-cluster) analog of this formalism is also described. Some practical issues are examined, including the choice of orbital basis. Illustrative numerical results are presented, based on the calculations of Iwata and Freed. Several remaining problems are described; these are both qualitative and quantitative in nature, and their resolution will require some detailed calculations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150207
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  • 41
    Electronic Resource
    Electronic Resource
    Colloquium on the structure small molecules adsorbed on surfaces (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 359-359 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150310
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  • 42
    Electronic Resource
    Electronic Resource
    Two-parameter exponential-type basis functions for atomic calculations (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 389-401 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is found that ordinary STOs fall off too fast in the atomic region in many cases. A new type of basis set, which is more adaptable to the rather different requirements of the various atomic orbitals in an atom, is developed. The suggested functional form χ(r) = Nrn-1 exp{-α[(βr + 1)1/2 - 1]} contains the STOs as a limiting case. Calculations on a series of atoms from H to Zn show that the new basis gives better results than STOs for equal basis set size. The necessary integrals do not present any problem to evaluate.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150405
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  • 43
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    Electronic Resource
    Valence photoelectron spectrum of CoO. Ab initio calculations of energies and relative intensities within a limited CI framework (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 403-410 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The valence spectrum of CoO has been calculated using the CoO610- cluster, stabilized by an electrostatic field, as a model of bulk CoO. The wave functions were generated using basis sets of better than double-zeta quality. SCF wave functions were obtained for the ground state and for the first ionized state of the cluster. Limited CI calculations were performed using these orbital sets. The lowest states of the ion correspond to the main lines in the spectrum, while higher states can give rise to high-energy satellites to the main lines. The relative intensities of these satellites were estimated in the case of high-energy incident photons.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150406
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  • 44
    Electronic Resource
    Electronic Resource
    Sagamore VI (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 445-445 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150409
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  • 45
    Electronic Resource
    Electronic Resource
    Neon L-shell photoabsorption cross sections from moment theory and finite basis pseudospectra (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 411-421 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pseudospectra from Gaussian basis set calculations within a frozen-core approximation have been used in a moment analysis to obtain Tchebychev profiles for the photoabsorption process in the valence shell of Ne. The profiles show good agreement with cross sections obtained in equivalent calculations using numerical atomic wave functions and continuum orbitals, particularly when the dipole-velocity form is employed. Variation of the basis sets shows that it is possible to obtain meaningful photoabsorption profiles using 13-15 virtual orbitals to describe the outgoing electron.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150407
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  • 46
    Electronic Resource
    Electronic Resource
    Role of Ca+2 ion in the abortifacient action of prostaglandins. I. Molecular-orbital and conformation-energy calculations of PGF2α (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 481-489 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The paper reports the study of a possible mechanism of Ca+2 activation of prostaglandin PGF2α on the basis of molecular-orbital and conformation-energy calculations. The electronic charges on various atoms of the molecule have been evaluated from the available crystallographic data by the extended Hückel theory (EHT). Conformation energies were calculated for intrinsic torsional rotations around the C11—C12, C7—C8, and C14—C15 bonds. The minimum energy conformation was found to differ from the crystallographic conformation by 9.3 kcal/mol. Some additional local energy minima are also reported within this range. The calculation of the long-range interchain interaction energy between the α and ω chains shows variation with conformation. The binding site for the Ca+2 ion has been estimated on the basis of the molecular electrostatic potentials. Such a binding site was found near the carboxyl group, which agrees with the current chemical thinking. Changes in the electronic charge distribution due to Ca+2 complexation were studied by EHT method using the supramolecular approach. Calcium complexation decreases the conformation energy by 2-3 kcal/mol and has a small effect on the interchain interaction energy.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150504
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  • 47
    Electronic Resource
    Electronic Resource
    Nonbonded interactions in membrane-active cyclic biopolymers. III. Analogs of valinomycin (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 491-497 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several analogs of valinomycin have been simulated. These are analogs obtained by changing the configuration of the amino acid and hydroxy acid residues one at a time. Nonbonded interactions have been calculated for three conformations of each analog. The electrostatic and polarization contributions to the energy are conformation selective, whereas the Pauli repulsion is the only component which is isomer selective. For the ring chirality considered here the analog of valinomycin having all the three L-valyl residues replaced by D-valyl residues is predicted to be frozen in a “top open” conformation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150505
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  • 48
    Electronic Resource
    Electronic Resource
    Ab initio study of a purine nucleoside: Adenosine (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 499-510 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ab initio SCF LCAO-MO method is used to compute the main electronic properties of a purine nucleoside, adenosine, in two specific conformational arrangements (3′-endo conformation of the ribose, gt orientation of the extracyclic CH2OH group, anti orientation of the base with respect to the sugar and 3′-endo conformation of the ribose, gg orientation of the extra-cyclic CH2OH group, syn orientation of the base with respect to the sugar). The results are compared with those performed for the isolated component fragments, adenine and 3′-endo riboses.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150506
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  • 49
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150601
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  • 50
    Electronic Resource
    Electronic Resource
    Cyanide-Isocyanide isomerization in the structural isomers of cyanogen isocyanate (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 547-557 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cyanide-isocyanide isomerization has been studied with ab initio calculations in an STO-3G basis as applied to NCNCO, NCCNO, NCOCN, and NCONC, and the corresponding isocyanides. Geometry optimization has been performed on these cyanides, their isocyanides, and their hypothetical transition states. The energies of isomerization were calculated to be 42.2, 29.8, 44.6, and 41.4 kcal/mol, respectively, while the energy barriers were found as 84.3, 67.5, 107.9, and 106.8 kcal/mol. Overlap populations and atomic charges were employed to provide simple correlations of the results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150510
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  • 51
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    Configuration-Interaction study of lower excited states of O2: Valence and rydberg characters of the two lowest 3Σu - states (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 533-545 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Configuration-interaction calculations, with an extended basis, are carried out on the ground and lower excited states of O2 and O2+ at and near the equilibrium internuclear distance (R = 2.3 a.u.) of the ground state of O2. Particular attention has been paid to the two lowest 3Σu- states, and the mixing of the valence and Rydberg characters in these states are studied. The lowest 3Σu- state is a Rydberg-type state for R 〈 2.3 a.u., but becomes valence-type for R ≳ 2.3 a.u. The second 3Σu- state, which is 1.6 eV above the lowest 3Σu- at R = 2.3 a.u., changes its character from Rydberg to valence, valence to Rydberg, and then to valence again when R increases from 1.9 to 3.1 a.u. Satisfactory agreement between the calculated and experimental vertical excitation energies is obtained.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150509
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  • 52
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    Ab initio molecular calculations with pseudopotentials: calculations of double-zeta quality on BeH2, BH3, CH4, and C2H6 (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 559-566 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new form of pseudopotential for applicaiton in ab initio molecular calculations is described. A method for determining pseudopotential parameters is suggested and pseudopotential parameters of double-zeta quality are presented for the first row atoms of the periodic table. The pseudopotential is especially well suited for incorporation into the floating-spherical-Gaussian-orbital (FSGO) method, though it is not restricted to any particular method. Applications of the resulting pseudo-FSGO method to BeH2, BH3, CH4, and C2H6 are presented.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150602
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  • 53
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    Ab initio molecular fragment calculations with pseudopotentials: Hydrocarbon calculations of double-zeta quality (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 567-578 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pseudopotential theory is introduced into the ab initio FSGO molecular fragment method. A theoretical background for the pseudopotential fragment description and a method for large molecule formation is presented. Core-valence electron separation is achieved at both levels of the calculations with the resulting simplification of the molecular calculations. Using pseudopotentials of double-zeta quality a detailed description of pseudopotential molecular fragments CH4 (tetrahedral) and CH3 (planar) is presented. Applications of the pseudo-FSGO molecular fragment method to hydrocaroons are discussed. The results are compared to those of the original FSGO method and experiment.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150603
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  • 54
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    Electronic Resource
    Spin-Free configuration-interaction study of molecules using single-parameter alternat molecular orbitals (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 579-588 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A procedure is outlined for a programmable spin-free configuration-interaction (CI) study in molecules using single-parameter alternant molecular orbitals for generating various configurations. The configurations were chosen to form bases for the irreducible representation {2N/2-2, 12S} of the general linear group GL(n). Using a transformation to biorthogonal space the CI matrix elements of a spin-free Hamiltonian were generated. The procedure has been used to obtain the π-electron energies for the 3,1Ag and 3,1Bu states of cis- and trans-butadiene.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150604
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  • 55
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    Electronic Resource
    Optical activity of nonrigid molecules (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 713-715 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Longuet-Higgins group is used to obtain an alternative formulation of a criterion for optical activity of nonrigid molecules recently given by Frei and Günthard.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150614
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  • 56
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    Electronic Resource
    Solitons, bioenergetics, and the mechanism of muscle contraction (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 5-17 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The properties of exciton and soliton excitations in one-dimensional molecular systems and in α-helical protein molecules are investigated. It is shown that collective excitations - solitons, corresponding to a combination of vibrational excitations in peptide groups and a local deformation of molecules - are possible in α-helical protein molecules. These excitations move along the molecule without energy losses and are perfect energy carriers. A qualitative description of the shortening in the length of muscular fibers is given using the concept of solitons occurring under the hydrolysis of ATP molecules at the ends of thick fibers contained in the sarcomeres of muscular fibers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160104
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    Are intermediate states responsible for certain specific properties of biological macromolecules? (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 31-42 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new electron structural mechanism is proposed for interpretations in molecular biology, in addition to the already existing theories of Szent-Györgyi (semiconductivity) and Fröhlich (long-range coherence). The hypothetical “intermediate-” or “zigzag states” (ZZS) of solids are investigated by the recursion (transfer matrix) method. The physical reality of the ZZS is discussed up to an SCF DODS-type theory and the necessity of additional less approximate investigations is emphasized. The possible role of ZZS in the explanation of: (i) translation in protein synthesis, (ii) energy and charge transfer processes, as well as (iii) initiation of protein formation is outlined.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560160106
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    Organization of phospholipids in biological membranes (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 19-29 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preferred conformations of phospholipids have been predicted through quantum-chemical techniques and classical potential functions. An essential condition for a conformation to exist in a biomembrane is that it should be possible for it to organize in the form of a bilayer. Taking into consideration the conformational flexibility of the polar head group, organization at the lipid-water interface has been considered. The biological implications of such an organization in terms of formation of “hydrophobic channels” is discussed. Quantum-mechanical investigations on the transport phenomenon have shown that the “selectivity” of biological membranes is connected with the “organization.” Calculations of the quantum-mechanical transmission coefficients for different model potential profiles indicate that minor differences in the height of potential barriers in certain regions can lead to significant changes in transmission coefficients. The “directional selectivity” of substrates (differences in transmission coefficients for flow in and out of the cell) can be explained on the basis of differences in membrane organization. These results have some important consequences in the evolutionary process in biological membranes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160105
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    Conformational changes and excitation energy transfer in myosin-auramine O system (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 43-50 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the myosin-auramine O system 10 or 11 binding sites of auramine O on the rod-like part of myosin were discovered. The myosin fluorescence decreases with an increase in auramine O concentration. This is evidence of the excitation energy transfer from tryptophanyls situated near the binding sites to auramine O. The effective distance of energy transfer is 35 Å. It is suggested that the light meromyosin has binding sites with periodicities of 77-86 Å. Every binding site has a negative charge and hydrophobic locus.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160107
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    What can quantum chemistry contribute to biology? (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 51-56 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The transition from quantum chemistry to quantum biology is discussed, and the contributions that quantum biology can make to the study of biological structure and process are outlined. The need for extensions to the theory to deal with larger systems, to include solvent effects and to account for specificity, are emphasized.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/qua.560160108
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  • 61
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    Ab initio molecular fragment calculations with pseudopotentials (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 57-64 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pseudopotential theory is introduced into the ab initio FSGO molecular fragment method. Pseudopotential molecular fragments using pseudopotentials of double-zeta quality are characterized, and a method of their assembly into larger molecules is presented. Core-valence electron separation is achieved at both levels of the molecular calculations. Heteroatom incorporation into the method is also considered. Applications of the pseudo-FSGO molecular fragment method to hydrocarbons and simple molecular systems containing heteroatoms are discussed. Results are compared to those of the original FSGO method and experiment.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560160109
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  • 62
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    Electron pair correlation energies for ZN2+ (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 65-70 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pair energies contributing to the correlation energies of the outer-shell electrons (n = 3) as well as for the 1s2 and 2s2 pairs are computed for the Zn2+ closed-shell ion by means of the variational-perturbation method starting with the sum of one-electron Hartree-Fock operators as the zeroth-order Hamiltonian. The results allow an understanding of the electron correlation for pairs of electrons of the p and d type. For 3p3d pairs it has been found that the correlation energy for the singlet pair of 1D symmetry is lower than for the triplet pair 3D. The 3l-3l′ correlation energies are compared with the MBPT results of Kelly and Ron for Fe. The total correlation energy of the outer shell is -1.032 a. u.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160110
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    Role of electron correlation in the quantum-mechanical calculations of the coulomb interaction energy in the DNA base pairs (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 71-77 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intermolecular electronic correlation contributions to the Coulomb component of the nucleic acid base interaction energy are estimated. The Coulomb energy is evaluated with the use of atomic monopoles, which are determined from the π-electronic densities calculated by the SCF method and by employing partially or completely optimized APSG wave functions. When the correlation is thus taken into account, a systematic decrease in atomic charges occurs; this effect is considerable only if an optimized orbital set is used. As a result, the Coulomb interaction energy due to the π-electronic atoms decreases from -1.13 to -0.85 kcal/mol for the AT pair and from -7.15 to -4.61 kcal/mol for the GC pair.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160111
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    Multimolecular clusters: Their isomerism and effective characteristics evaluated by quantum chemistryPart V in the series Multimolecular Clusters and Their Isomerism; Part IV, Ref. 25. (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 79-86 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is described for processing the enthalpy, entropy, and Gibbs free energy terms of formation of the individual isomers of n-particle clusters obtained by means of quantum-chemical calculations, to enable a comparison of these partial theoretical characteristics with the overall experimental ones. The general scheme of weighting treatment is illustrated by examples based on recent quantum-chemical results of studies of isomeric forms of (NO)2, (H2O)5 and (D2O)5, and CH3OH · 3H2O and CH3OH · 6H2O clusters.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160112
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    Electronic factors affecting receptor binding of dibenzo-p-dioxins and dibenzofurans (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 87-110 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electronic structure of a series of 25 chlorinated dibenzo-p-dioxins and dibenzofurans has been characterized by means of the ab initio molecular fragment technique. This information has been employed to investigate some of the factors affecting the affinity of the molecules for the hepatic cytosol binding species described by Poland, Glover, and Kende. A quantitative structure-activity relationship involving electronic and steric parameters could be established from the data. It appears that the toxins act as electron acceptors in a charge-transfer complex with the receptor.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160113
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    Circular dichroism of large molecules (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 111-117 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The circular dichroism of molecules, which are large compared to the wavelength of light, is considered. Explicit expressions are obtained for the circular dichroism and absorption of an exciton dimer and of a free particle on a helix. The dimensions are described for which the dipole approximation for the optical properties fails.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160114
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    Mechanisms of electron transfer through proteins (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 133-152 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The analysis of modern physical mechanisms of electron transfer in proteins is given. The tunnel electron transfer and donor-acceptor electron transfer through conducting states of a protein chain are discussed in detail. The expressions for the values of the electron resonance interaction and the formulas for probabilities of electron transfer between vibronic levels of donor and acceptor states in the presence of “transverse” and “longitudinal” relaxation are given.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160116
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    Some aspects of the DNA hypochromic effect theory (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 119-132 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The expressions for the polymer absorption band hypochromism and oscillator strength are studied in frames of the first-order perturbation theory. The physically justified approximations for a polymer hypochromism calculation are indicated. The uniform interpretation of the effect origin is given independently on the approximation used. In frames of the perturbation theory the DNA hypochromism formula is obtained, from which the known experimental dependences of hypochromism on chain length and polymer helicity degree follows directly. The analytic expression of the DNA hypochromism dependence on AT pairs content is obtained. It is established that in most cases for natural DNA the nucleotide sequence does not influence in practice the value of the hypochromic effect.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560160115
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    Conformational analysis of double-helical polynucleotides (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 153-157 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intramolecular interaction energy of the regular double-helical polynucleotide as a function of variables that determine the mutual position of base pairs and sugar pucker was calculated using atom-atom potentials. The calculations showed the existence of two valley-like regions with minimal values on the energetic surface. One of them corresponds to the A family of nucleic acids, the other to the B family. The points that correspond to the models constructed by means of x-ray data are placed in a conformational space near the lines that describe the position of the bottom of the valleys.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160117
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    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160201
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    Influence of solvent structure on the conformation of the native DNA molecule (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 847-855 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The investigation of the factors determining the formation and stability of the higher biopolymers structures is one of the most important trends of the development of molecular biophysics. A feature common to most macromolecular systems under physiological conditions is that they function in an aqueous environment. Thus, it is natural to assume that the peculiarities of biological macromolecules structures and their functional activity as well are closely related to the specific properties of such a unique solvent as water. The investigations of the conformational changes of biopolymer, induced by dehydration of the macromolecule, give information about the nature of the forces stabilizing its structure. The dehydration of the macromolecule in solution can be attained by addition of a nonaqueous cosolvent. Generally low-molecular-weight aliphatic alcohols, amides, and amines are used as a nonaqueous component. At present a vast number of experimental and theoretical data concerning the properties of water and aqueous systems are available. The specificity of water as a solvent arises primarily from the spatial hydrogen-bonded structure. The addition of a nonaqueous component exerts changes in this structure, which evolve to the singularities of the physical characteristics of water-nonelectrolyte mixtures. It is generally assumed that nonelectrolytes may be divided, according to their effect on the spatial water structure, largely into two basic classes: (1) the structure makers, i.e., the compounds of aliphatic alcohols type; (2) the structure breakers, i.e., the compounds of urea type. The agents belonging to the first class show a stabilizing effect in the range of low nonelectrolyte content. At a certain critical concentration, Ccrit, characteristic of each substance, the nonaqueous solute molecules leave the cavities of the spatial water structure which leads to a disruption of the latter. The agents belonging to the second class exert a structure-breaking effect even in the range of extremely low concentrations, which arises from their high competitive ability for hydrogen bonding.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560160417
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    Mechanisms of charge separation in bacterial photosynthesis (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 877-882 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The physical aspects of the primary charge separation processes in bacterial photosynthesis are discussed. The donor-acceptor model of electron transfer due to participation of protein current states is used. The kinetics of photosynthetic reaction center (PRC) processes is investigated and the PRC energetic scheme is constructed using the nonequilibrium density matrix method. It is shown that with allowance for the effect of vibrational sublevels of states participating in transitions the theory describes well experimental data.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160421
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    Orbit-orbit interaction in the NO-Fe(II)Hemoproteins studied by the low-temperature magnetic circular dichroism: Dynamic Jahn-Teller effect detected by MCD (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 883-889 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper analyzes the low-temperature magnetic circular dichroism of NO-Fe(II)hemoproteins in detail. We include the Jahn-Teller effect in our consideration of the low-temperature MCD results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160422
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    Quantum-chemical investigation of spatial and electronic structure of verdazyl and its derivatives (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 891-895 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The unrestricted HF method in the INDO approximation with optimized geometry was used to describe the electronic structure of the hetero-ring of verdazyl and the derivatives of the latter. The results obtained are in good agreement with the experimental EPR spectra of triphenylverdazyl radical and its dipole moment. These data may be a basis for understanding and predicting the chemical properties and reactivity of verdazyl and its derivatives.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160423
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    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160501
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    Atomic energy levels and oscillator strengths calculated with a screened potential (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 83-95 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A screened potential model (SPM) is formulated with Slater-type functions to reproduce the density of the electron shells. The orbital exponent for the valence shell is optimized to calibrate the SPM against experimental valence and Rydberg s and p energy levels for the alkali metals (Li, Na, and K) rare gases (He, Ne, Ar, and Kr), second-row atoms, and Cu, Zn, Mg, S, and Ga. The resulting one-electron wave functions are used to calculate the dipole and velocity forms of the oscillator strengths and 〈1/r3〉 for spin-orbit coupling. The excellent agreement with the averaged experimental results suggests that the SPM atomic orbitals are a good starting point for the evaluation of one-electron properties.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150109
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    Comparison of UHF and PHF methods for hyperfine structure calculations (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 97-107 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The validity of two models used in comparisons of the UHF and PHF methods in hyperfine structure calculations is investigated for the lowest 2P state of Li. An improved model for the angular splitting of the core orbitals is proposed and shown to give an accurate description of both the UHF and the PHF wave functions.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/qua.560150110
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    14th Meeting of the international academy of quantum molecular science (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 131-131 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150113
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    Study of the quality of Gaussian basis sets for carbon and silicon: Calculations on methane and silane (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 261-270 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A number of Gaussian basis sets for carbon and silicon have been examined in terms of the one-electron properties of methane and silane. The convergence of the properties to their limiting values is not monotonic but, in general, a representation that involves five Gaussian functions per occupied atomic orbital on the heavy atom is sufficient to closely approach the limits. A relationship between the sizes and partitioned electronic energies is shown to hold to a good approximation for the Boys spatially localized molecular orbitals employed in this study.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150302
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    Surface structure and energy spectra of localized states (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 281-291 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A simple model for surface reconstruction is developed utilizing the next-nearest-neighbor approximation within the framework of molecular-orbital theory. Exact energy expressions for this model and various special cases are derived, and they are illustrated by numerical results. The influence of a very weak surface deformation on the energy spectrum of surface states is also discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150304
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    Modified bielectronic potential method for correlation energy (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 293-309 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Löwdin's correlation potential formalism has been used to define a modified bielectronic potential, allowing one to calculate the exact electronic energy, given the Hartree-Fock wave function. This modified potential is in principle peculiar to each electronic system, and is defined by a correlation factor depending on the interelectronic distance r2. The explicit calculation of the correlation factor has been performed for some two-electron atoms, in the 11S and 23S states, and for the beryllium atom. Examination of the results so obtained leads us to conclude in favor of the nonexistence of a universal modified bielectronic potential.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150305
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    Model quantum chemical studies of the electronic structure and aspects of reactivity of diol epoxides of aromatic hydrocarbons (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 271-280 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper offers a unified presentation of the main ring conformers of the diol expoxides, triol carbonium ions, and tetrols related to the “bay-region” benzo ring of carcinogenic metabolites of PAH and brings forward quantitative information through ab initio SCF computations about their relative energies. It substantiates and evaluates the energy of the syn epoxide-OH4 hydrogen bond and, on the contrary, refutes the significance of an O⃛H—O or an O-⃛H—O bond in the triol carbonium ions. It provides an explanation for the similar rates of acid-catalyzed hydrolysis of the syn and anti diol expoxides. It evaluates the stabilization of the triol carbonium ions due to the presence of a neighboring double bond and accounts for the spontaneous opening of protonated epoxides. Finally it accounts for cis hydrolysis of the syn diol epoxide and trans hydrolysis of the anit diol epoxide under acid conditions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150303
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  • 83
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    A dynamical theory describing superconductant DNA (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 333-341 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A dynamical model describing DNA as superconductant is proposed. The status of superconductivity is described as being represented by a radiation-induced harmonic oscillation of a parcel of π electrons between the reference level and critical temperatures. A set of field equations is used to describe the information exchange process mediated by a coherent wave phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150307
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  • 84
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    Electronic Resource
    Theoretical studies of hemoproteins. I. Mathematical description of the allosteric effect (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 379-387 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new theoretical approach to the cooperativity of an enzyme has been proposed. When we applied the present theory to the allosteric effect of hemoglobin, we obtained a so-called Koshland-Nemethy-Filmer formula. Our theory suggested that the sigmoid curve becomes sharper when the affinity of the first oxygen molecule of the hemoglobin is smaller.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150404
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  • 85
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    Electronic Resource
    Atomic dipole approximation and energies of interactions between purine and pyrimidine bases. I. Electrostatic interactions of adenine with uracil, thymine, thiouracils, dihydrouracil, and 5-fluorouracil (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 369-377 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The atomic dipole approximation has been employed to calculate the energies of electrostatic interaction between adenine and various pyrimidine derivatives. Minima of the interaction energy for various planar configurations were determined. Inclusion of the “monopole-dipole” and “dipole-dipole” terms in the multipole expansion improves considerably the agreement with experimental data. The effect of sulfur substitution has been investigated in detail. Formation of N—H…S hydrogen bonds is less favorable than of N—H…O bonds, due largely to the lower atomic dipole of the sulfur atom resulting from the shift of the π-electron charge toward the neighboring carbon. The results are relevant to the interactions of thiouracils in nucleic acids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150403
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  • 86
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    Electronic Resource
    Invariance properties of the multipole expansion with respect to the choice of the coordinate systemthis work was partially supported by the polish academy of sciences within the project mr.i.9. (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 701-711 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The physical interpretation of intermolecular interactions is usually based on the well-known multipole expansion of the inverse of the interparticle distance. The interaction energy is then interpreted as a sum of terms arising from the interaction of various multipole moments of both systems. It is supposed that the interaction energy calculated via the truncated multipole expansion generally depends on the choice of local coordinate systems through the coordinate dependence of the multipole moments. In this paper we prove that each term of the multipole expansion given in the form ∑k = 1 Ck/Rk is invariant with respect to identical translations and arbitrary rotations of the local coordinate systems. The invariant form of the convergence criterion of the multipole expansion is given and discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150613
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  • 87
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    Electronic Resource
    Power moments of hydrogenic Green's functions and Green's functions of the second kind (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 717-729 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Power moments for all of the reduced hydrogenic Green's functions have been computed. These moments have the same form as the corresponding moments of the free-particle Green's functions. Green's functions of the second kind are defined, and uses for these objects in model potential theory and the theory of many-body Green's functions are pointed out. In the case of the ground state of the hydrogenic atom, the Green's function of the second kind has been given.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150615
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  • 88
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    Electronic Resource
    Improved uncoupled Hartree-Fock (IUCHF) perturbation methods and bounds for the second-order energy in coupled Hartree-Fock perturbation theory (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 745-750 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Different kinds of improved uncoupled Hartree-Fock methods are proposed for the calculation of second-order perturbation energies. Using these methods inequalities are derived for the error of the uncoupled procedure with geometric approximation.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150617
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  • 89
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    Electronic Resource
    Space partitioning in multiple scattering techniques. I. Hydrogen molecular ion and hydrogen molecule (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 731-744 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of multiple scattering techniques combined with a statistical exchange potential for the description of the electronic structure of atoms, molecules, and solids depends strongly on the geometry (muffin tin, overlapping spheres, or cellular potentials) and on the form of the electron gas exchange. In this work we compare only the effects of using different geometries. For that purpose we have done calculations on the hydrogen molecular ion and Hartree-type calculations on the hydrogen molecule so that no exchange effects are involved. To avoid arbitrariness in the choice of the sphere sizes we propose a nonempirical criterion that consists of using the set of radii that will minimize the charge in the interstitial region of the molecule or cluster. Some arguments are given to justify this criterion, and to clarify the differences between cellular, overlapping spheres, and muffin-tin geometries. It is found that the cellular geometry gives a very good description around the equilibrium internuclear distance. However, for most systems of interest, exchange will be present. Thus, we have done, for comparison, the calculation on H2 using Xαβ statistical exchange. It is shown through this calculation that some of the correlation energy may be obtained by redefining the molecular orbitals in terms of non-paired-spins spatial orbitals, this formulation being required to obtain the correct free-atom limit.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150616
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  • 90
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    Spin-Free Quantum Chemistry. XXI. Hartree-Fock theorySupported by the Robert A. Welch Foundation of Houston, Texas. (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 751-767 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The theory of the open-and closed-shell restricted Hartree-Fock method is given a unitary group formulation. Both extremum and stability conditions are employed, the former leading to a generalized Brillouin theorem.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150618
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  • 91
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    Electronic Resource
    Improved interaction potential for alkali halide molecules (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 769-782 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An improved interaction potential has been devised for diatomic alkali halide molecules. This potential, in addition to similar attraction terms as in the Rittner potential, includes a new exponential for the short-range repulsion. The constant m in the exponential is seen to be well expressible in terms of the parameters of the Rittner potential. The new potential is also correlated with different properties, as for example, effective charges, effective radii, effective principal quantum numbers, etc., of the combining ions. Various spectroscopic constants, viz., the ionic dissociation energy Di, the vibrational-rotational coupling constant αe, the vibrational anharmonicity constant ωexe, as well as two second-order spectroscopic constants γe and βe have been calculated for this and for the Rittner potential. From comparisons between these two potentials, the new one has been observed better than the other.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150619
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  • 92
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    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160101
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  • 93
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    Nuclear magnetic resonance spectroscopy in molecular biology. Proceedings of the Eleventh Jerusalem Symposium on Quantum Chemistry and Biochemistry held in Jerusalem. Israel, April 3-7. 1978. B. Pullman, Ed. D. Riedel Publishing Company, Dordrecht, Holland. 1978. 532 pp. Price: $56.00. (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 793-793 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150621
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  • 94
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    Electronic Resource
    On the polarity of the amide group and its impact on dipeptide conformation (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 15 (1979), S. 783-792 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Giving explicit consideration to the lone pairs of the carbonyl oxygen of the amide group it is found that the polarity of the amide group resides essentially in the lone pair. As a confirmation, the lone pairs of the ester group are also found to account for most of its polarity. This localization of amide dipole affects the dipeptide conformation map only in the unallowed regions of the map, but has significant impact on the dipole moment of the dipeptide in different conformations. The experimentally observed dipole moments of dipeptides in solution are in conformity with our assignment of polarity of the amide group.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560150620
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  • 95
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    Preface (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 1-2 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160102
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  • 96
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    Introduction (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 3-4 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160103
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  • 97
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    Electronic Resource
    Geometry of ammonia molecule in the lowest triplet state estimated theoretically (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 261-264 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The geometrical parameters of the ammonia molecule in the lowest-lying triplet state have been estimated by means of the SCF method and by making an extrapolation to take into account electron correlation effects. The planar configuration has been obtained as the most probable geometrical arrangement (3 A2″).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160207
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  • 98
    Electronic Resource
    Electronic Resource
    Electrostatic isopotential maps for large biomolecules (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 265-272 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new method for the calculation of electrostatic isopotential maps, based on completely transferable bond orbitals, is proposed. According to the simple form of the potential term the amount of computational work is proportional to the first power of the number of valence electrons. Slater-type atomic orbitals are used to construct the bond orbitals, thus all integrals can be calculated explicitly. The subtilisin charge-relay system is studied as an example. It is found, in agreement with the results of Beppu and Yomosa, that the two protons transfer in a stepwise manner.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160208
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  • 99
    Electronic Resource
    Electronic Resource
    Excited electronic states of a hydrogen bond: Bifluoride ion (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 273-275 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report here a summary of a limited CI calculation carried out on the C∞v and D∞h electronically excited states of bifluoride ion. This species is interesting as the prototype of a hydrogen-bonded system. It is determined that the lowest-lying excited states of the system are dissociative and/or autoionizing.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160209
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  • 100
    Electronic Resource
    Electronic Resource
    Theoretical studies on substrate binding to the active site of carbonic anhydrase (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 16 (1979), S. 293-298 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The role of some amino acids and metal ions in the catalytic activity of carbonic anhydrase (carbonate dehydratase EC 4.2.1.1) has been investigated. The additional stabilization of the transition state complex was used as the qualitative measure of the effect of molecular surrounding on CO2 hydration reaction calculated within the approximate CNDO/2 approach. The effect of the molecular environment has been simulated by inclusion into the SCF LCAO MO Hamiltonian, a term representing the interaction with a set of point charges and atomic dipoles centered on experimentally determined position of Zn2+ ion and all atoms of histidine 94, 96, 119 and threonine 199, 200 (or histidine 200 in the case of carbonic anhydrase B). The possible molecular mechanism of CO2 hydration inside the active site has been also discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560160211
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