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  • 1
    Electronic Resource
    Electronic Resource
    1H-, 13C-, and 113Cd-nmr study of the Cd(II) complex of a blocked peptide, Z-Cys-Ala-Pro-His-OMe, in organic solvents (1995)
    New York : Wiley-Blackwell
    Biopolymers 35 (1995), S. 319-329 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Cd(II) complex of a peptide, Z-Cys-Ala-Pro-His-OMe was prepared and characterized by absorption, CD, 1H-, 13C-, and 113Cd-nmr, and nuclear Overhauser effect spectroscopy (NOESY) spectra to show the coordination of cysteine thiolate and histidine imizazole to Cd(II) ion. The NOESY spectra in dimethyl formamide showed that the cysteine residue was in proximity to the histidine residue. These results reveal the dictation of Z-Cys-Ala-Pro-His-OMe to Cd(II) ion in solution. Temperature-dependent dissociation equilibrium of histidine imidazole in solution was observed in this complex. Structural features of the chelating peptide are discussed. © 1995 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360350307
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  • 2
    Electronic Resource
    Electronic Resource
    Photochemische Reaktionen 115. Mitteilung [1]. Zur Photochemie konjugierter γ,δ-Epoxyenone: Der Einfluss eines Hydroxylsubstituenten in ∊-StellungMit den besten Wünschen Herrn Dr. Willy G. Stoll zum 70. Geburtstag zugeeignet (1980)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 63 (1980), S. 2230-2257 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Conjugated γ,δ-Epoxyenones: The Influence of a Hydroxy Substituent in ∊-PositionOn 1n, π*- or 1π,π*-excitation (λ ≥ 347 or λ=254 nm), the ε-hydroxy-γ;,δ-epoxyenone 8 undergoes fission of the C(γ)—O bond followed by the cleavage of the C(δ)-C(ε) bond. This hitherto unknown sequence of reactions is evidenced by the structure determination of the new type products 10-17 and 25, including a synthetic proof for 12 and the X-ray analysis of 11 (X-ray data: triclinic P1; a=7,386(2), b=8,904(4), c=9,684(5)Å; α=82,29(4)°, β=74,46(3)°, γ=82,29(3)°; Z=2).The selective 1π,π*-excitation also induces competitive C(γ)-C(δ) bond cleavage to yield the bicyclic acetal 18 and a ketonium-ylide intermediate a, which photochemically forms a carbene b giving the allene 19 and the cyclopropene 20.On 1n,π*-excitation of the acetate 9 the initial C(γ)-O bond fission is, in contrast to the behaviour of the corresponding alcohol 8, followed by a 1,2-methyl shift affording (E/Z)-28 or by a cyclization-autoxidation process yielding the lactone 29.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19800630813
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  • 3
    Electronic Resource
    Electronic Resource
    Photochemische Reaktionen 130. Mitteilung129. Mitteilung s. [1].. Zur Photochemie von 5,6-Epoxy-1,3-dienen: Der Einfluss eines 7-Hydroxysubstituenten auf die CarbenbildungTeil II; Teil I s. [2]. (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 2236-2251 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of 5,6-Epoxy-1,3-dienes: Influence of a 7-Hydroxy Substituent on the Carbene FormationOn singlet excitation (λ=254 nm) in MeCN the hydroxy-epoxydiene (E)-4 undergoes photocleavage to the carbene intermediates d and e as main processes. The carbene d, showing behaviour typical of vinyl carbenes, undergoes addition to the adjacent double bond furnishing the cyclopropenes 5A + B. The carbene e, however, undergoes an insertion reaction into the neighbouring carbinol C,H-bond leading to the enol intermediate 21, which gives rise to the compounds 6A + B and 7A + B. To a lesser extent the products 8A + B are formed via another enol intermediate (32). On photolysis of (E)-4 in MeOH instead of MeCN the enol intermediates 21 and 32 undergo rapid tautomerisation to the ketones 9A + B (main products) and 11.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660735
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  • 4
    Electronic Resource
    Electronic Resource
    Norbornadiene(bipyridyl)molybdenum(II) Complexes: Synthesis, Structure and Reactivity of [Mo(CO)(C7H8)(C10H6R2N2)X2] (X = I, Br)Dedicated to Professor Dr. Helmut Werner on the occasion of his birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1007-1013 
    Details
    ISSN: 0009-2940
    Keywords: Tetracarbonyl(norbornadiene)molybdenum(0) ; Oxidative addition of I2 ; Dihalogeno(bipyridyl)molybdenum(II) complexes ; 7-Coordinated complexes ; Neutral and cationic molybdenum(II) complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of [Mo(CO)4(C7H8)] (1) with I2 gave the norbornadienemolybdenum(II) complex [Mo(CO)2(C7H8)I2]n≥1 (2), which existed in an equilibrium of two isomeric forms. In acetonitrile, 2 reversibly formed the adduct [Mo(CO)2-(C7H8)(NCCH3)I2] (3), whereas on treatment with 2,2′-bipyridine or 4,4′-di-2,2′-tBu-bipyridine, it gave stable 7-coordinated molybdenum(II) complexes, [Mo(CO)(C7H8)-(C10H8N2)I2] (4) and [Mo(CO)(C7H8)(C10H6tBu2N2)I2] (5), in good yield. In similar reactions, the related dibromomolybdenum compounds [Mo(CO)(C7H8)(C10H8N2)Br2] (6) and [Mo-(CO)(C7H8)(C10H6tBu2N2)Br2] (7) were prepared by oxidation of 1 with two equivalents of CuBr2. The X-ray structural analysis of 6 reveals that the geometry around the molybdenum atom is nearly perfectly pentagonal bipyramidal, with the CO and one of the bipyridyl rings perpendicular to the plane formed by the other ligands. The compounds 5 and 6 react with AgSbF6 by halogen abstraction to give cationic complexes, {[Mo(CO)(C7H8)(C10H8N2)Br]SbF6}n≥1 (8) and {[Mo(CO)(C7H8)(C10H6tBu2N2)I]SbF6}n≥1 (9): In acetone, 8 and 9 reversibly formed the adducts [Mo(CO)(C7H8)(C10H8N2)(acetone)Br]SbF6 (8′) and [Mo(CO)(C7H8)(C10H6tBu2N2)(acetone)I]SbF6 (9′); while on treatment with PMe3, the stable monomeric complexes, [Mo(CO)(C7H8)(C10H8N2)(PMe3)Br]SbF6 (10) and [Mo(CO)(C7H8)(C10H6tBu2N2)(PMe3)I]SbF6 (11), were isolated in almost quantitative yield. In the presence of KBr, compound 8′ reverted to the dibromo complex 6, whereas 9′ reacted to produce a 1:1:2 mixture of 5, 7 and the bromo(iodo) complex [Mo(CO)(C7H8)(C10H6tBu2N2)BrI] (12). The same mixture is available from the reaction of 5 with one equivalent of 7.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281008
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  • 5
    Electronic Resource
    Electronic Resource
    Novel Aromatic Azopolymers with Regularly Interposed Tellurium Atoms in the Backbone (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 703-709 
    Details
    ISSN: 0009-2940
    Keywords: Copolymers ; Electrical conductivity ; Azo compounds ; Tellurides, organo ; Telluration ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Previously unknown alt-copoly(telluro-1,4-phenylene/azo-1,4-phenylene) and related polymers were synthesized by several different approaches, which include a) reductive polymerization of bis(4-nitrophenyl) tellurides with zinc; b) oxidative polymerization of bis(4-aminophenyl) telluride using a CuI/CuII redox system as catalyst under oxygen; c) electrochemical polymerization of bis(4-amino-3,5-dimethylphenyl) telluride; d) condensation polymerization of 1,4-dinitrosobenzene with bis(4-aminophenyl) telluride Te, Te-dichloride, and e) condensation polymerization of bis(4-nitrophenyl) telluride with bis(4-aminophenyl) telluride in the presence of sodium hydroxide. The polymers obtained were characterized by elemental analysis, 13C-CPMAS NMR, IR and UV-vis spectroscopy, GPC, and inherent viscosity measurements, and their properties were examined, particularly their electrical conductivity. The electrical conductivities of the new polymers 9b c, and 10 were shown to increase from below 10-7 up to 10-5 ∽ 10-2 S cm-1 upon bromine doping in spite of their formally interrupted conjugation structure.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280708
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  • 6
    Electronic Resource
    Electronic Resource
    Polymerization of 1,3-cycloheptadiene and the structure of poly(1,3-cycloheptadiene)s obtained by ionic initiators (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 215-217 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.021820123
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  • 7
    Electronic Resource
    Electronic Resource
    On the salt-linkage formations of porous and nonporous silica particles with trimethylammonium glycol chitosan iodide (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 1715-1724 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The stoichiometry of the salt-linkage formations of nonporous and porous silica particles with trimethylammonium glycol chitosan iodide (TGCI) was investigated by comparing the results of colloid titration and adsorption experiments with those of potentiometric titrations. The surface charge (Q) of colloidal silica as function of pH was evaluated by means of the colloid titration with TGCI. On the other hand, the density (D) of ≡ SiO⊖ groups of silica gel at different pH was also evaluated by the adsorption experiment of TGCI. These results obtained were compared with the Q vs. pH and D vs. pH curves which were obtained by the potentiometric titrations at various ionic strengths for colloidal silica and silica gel, respectively. It was concluded that the ≡ SiO⊖ groups on the surface of nonporous colloid silica form the salt-linkages stoichiometrically with ⊕N(CH3)3-groups in TGCI, whereas the salt-linkage formation between ⊕N(CH3)3-groups in TGCI and ≡ SiO⊖ groups of silica gel does not follow the stoichiometric relationship, since the salt-linkages of the ≡ SiOominus; groups in the pores of the silica gel could be affected by the steric hindrance of the TGCI chain.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.021820612
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  • 8
    Electronic Resource
    Electronic Resource
    Preparations and asymmetric, reducing abilities of chiral polymeric amine-boranes (1980)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 2563-2569 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymeric amine-boranes 2b, 4b, and 8c and their corresponding low-molecular-weight model compounds 3b, 5b, and 6b were obtained by reaction of chiral amines with diborane; these amines were poly(pyrrolidine-1,2-diylmethylene) (2a), poly(imino-1-isobutylethylene) (4a), poly{[1,2-bis(4-vinylphenyl)ethyl]amine} (8b), 1-methylpyrrolidin-2-yl-1-pyrrolidinyl-methane (3a), N1-isopentyl-N2-methyl-4-methyl-1,2-pentanediamine (5a), and α-phenylphenethylamine (6a). The polymeric amine-boranes are white powders, stable to be kept for several weeks at room temperature, whereas the low-molecular-weight model compounds are less stable syrup-like materials. The reduction of acetophenone to optically active 1-phenylethanol was carried out with the chiral amine-boranes in the presence of boron trifluoride etherate at various reaction temperatures. The product resulting from the reduction with 8c can easily be separated from the reaction mixture by filtration. The optical yield of the product obtained with 8c was 8,9% at -40°C. The highest optical yield (25,3%) was obtained with α-phenylphenethylamineborane 6b at 0°C.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1980.021811213
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  • 9
    Electronic Resource
    Electronic Resource
    Preparation of poly[(3S)-1,2,3,4-tetrahydroisoquinoline-2,3-diylmethylene] and its use as chiral catalyst in the addition of arenethiols to 2-cyclohexen-1-one (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 675-679 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly[(3S)-1,2,3,4-tetrahydroisoquinoline-2,3-diylmethylene] (4) and (3S)-3-(1,2,3,4-tetrahydroisoquinolin-2-ylmethyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (7) were prepared using (3S)-1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid (1) as starting material. The optically active amines 4 and 7 were used as asymmetric catalysts for the addition of thiophenol (8a), 4-tert-butylthiophenol (8b), or 4-chlorothiophenol (8c) to 2-cyclohexen-1-one (9). 4 yielded 3-phenylthiocyclohexanone (10a) with the highest optical yield of 24% at -25°C, showing a marked polymer effect with respect to enantiomeric excess.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021840401
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  • 10
    Electronic Resource
    Electronic Resource
    Stoichiometric salt-linkage formation of trimethylammonium glycol chitosan iodide with a carboxylic type ion exchanger (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 1233-1238 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The adsorption of trimethylammonium glycol chitosan iodide (TGCI) on Dowex CCR-2 resin was investigated at different pH values and resin weights. The concentration of Na+ or Ca2+ ions, released by the ion exchange reaction with TGCI, was measured by inductively coupled plasma spectroscopy. It was found that the amount of the released ions is comparable to that of the absorbed TGCI. This indicates that the salt-linkage formation of carboxylate ions of the exchanger with ⊕N(CH3)3-groups in TGCI follows a stoichiometric relationship. This result is discussed in connection with the form of the polymer layer adsorbed on the solid surface.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021830517
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