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  • Inorganic Chemistry  (57)
  • Organic Chemistry  (3)
  • 1-Metalla-1,3,5-trienes of tungsten, cyclization to cyclopentadiene complexes  (1)
  • 11
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 1448-1459 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substitution Reactions at Tetrasulfur TetranitridedichlorideThe reaction of S4N4Cl2 (1) with trimethylsilyl-substituted sulfodiimides in the molar ratio 1:1 leads to derivatives of pentasulfur hexanitride 2a and b. The structure of 2a was established by single X-ray crystal analysis. 1 reacts with trimethylsilyl-substituted amines to yield 1,5-bis(amino)-tetrasulfur tetranitrides 3a-c. The different orientation of the substituents was established by temperature-dependent 1H NMR investigations. In 2 and 3 the cage structure of the unsubstituted S4N4 is preserved.
    Notes: Durch Reaktion von S4N4Cl2 (1) mit trimethylsilyl-substituierten Sulfodiimiden im Molverhältnis 1:1 erhielten wir Derivate des Pentaschwefelhexanitrids 2a und b. Die Struktur von 2a wurde anhand einer Einkristallröntgenstrukturanalyse aufgeklärt. 1 reagiert mit trimethylsilyl-substituierten Aminen zu den 1,5-Bis(amino)tetraschwefeltetranitriden 3a-c. Die unterschiedliche Orientierung der Substituenten konnte durch temperaturabhängige 1H-NMR-Untersuchungen belegt werden. In 2 und 3 bleibt die Käfigstruktur des freien S4N4 erhalten.
    Additional Material: 3 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3227-3240 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: λ5-Di- and -Triazaphospholines - Synthesis, Isomerization, and DecompositionThe reaction of amino[(trimethylsilyl)methylene]thioxophosphorane 1 with diazoalkanes leads to Δ1-diazaphospholines 3, 7, 11, and 12. These sensitive compounds are stabilized by 1,3-migration of a trimethylsilyl group, where 3 and 7 end in the Δ2-diazaphospholines 4 and 8 and 11 and 12 decompose by [1 + 4]cycloreversion to give the azines 14 and 15 as well as aminothioxophosphane intermediate 13. 13 could be trapped by reaction with diazoalkanes as aminomethylenethioxophosphoranes (18 and 19). The corresponding phosphane system 20 and 21 is available by reduction of 18 and 19, respectively, with triphenylphosphane. tert-Butyl azide (22) and 1 form triazaphospholine 23, which isomerizes thermally by silyl migration to give 24. Photochemically induced elimination of N2 leads to the λ5-azaphosphiridine 25; this system is also accessible by reaction of aminoiminothioxophosphorane 26 with diazomethane. In contrast, thermal reaction of trimethylsilyl azide (30) and 1 results in a λ5-thiaphosphirane 31. Compounds of this type (31, 32) can also be synthesized by [1 + 2]cycloaddition of sulfur and the corresponding iminomethylenephosphorane. - The X-ray structure analysis of the Δ2-diazaphospholine 5 is described, NMR data and decomposition of di- and triazaphospholines are discussed.
    Notes: Amino[(trimethylsilyl)methylen]thioxophosphoran 1 reagiert mit Diazoalkanen zu den Δ1-Diazaphospholenen 3, 7, 11 und 12. Diese stabilisieren sich unter 1,3-Trimethylsilyl-Verschiebung zu den Δ2-Diazaphospholenen 4 und 8 bzw. zerfallen unter [1 + 4]-Cycloreversion zu Azin (14 und 15) und dem Aminothioxophosphan 13. 13 konnte durch Reaktion mit Diazoalkan als Aminomethylenthioxophosphoran (18 und 19) abgefangen werden. Durch Entschwefelung von 18 bzw. 19 mittels Triphenylphosphan ist das entsprechende Phosphan-System 20 bzw. 21 zugänglich. tert-Butylazid (22) reagiert mit 1 zum Triazaphospholen 23, das thermisch unter Trimethylsilyl-Wanderung zu 24 isomerisiert und photochemisch unter N2-Eliminierung das λ5-Phosphiridin 25 liefert, ein Verbindungssystem, das ebenfalls durch Umsetzung eines Aminoiminothioxophosphorans (26) mit Diazomethan zugänglich ist. Bei der thermischen Reaktion von 1 und Trimethylsilylazid (30) wird hingegen das λ5-Thiaphosphiran 31 erhalten. Verbindungen dieses Typs (31, 32) sind auch durch Schwefelung der entsprechenden Iminomethylenphosphorane zugänglich. - Die Röntgenstrukturanalyse des durch partielle Hydrolyse von 4 erhaltenen Δ2-Diazaphospholens 5 wird angegeben, und die NMR-Daten sowie der Zerfall der Di- und Triazaphospholene werden diskutiert.
    Additional Material: 5 Tab.
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  • 13
    ISSN: 0009-2940
    Keywords: Aminocarbene complexes of iron ; N-Vinylaminocarbene complexes ; π-Allyl,σ-complexes of iron ; N-(2-Propenyl)aminocarbene complexes ; Methylenation of ketene imines by carbene complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses with Transition Metal Complexes, 52 1). - N-Vinylaminocarbene and N-(2-Propenyl)aminocarbene Complexes by Addition of Ketene Imines to Carbene Iron ComplexesKetene imines R(Me)C = C = NPh (2, R = Me, Et, i-Pr) form 1 : 1 adducts with the carbene iron complex (CO)4,Fe=C(OEt)Ph (1). The initial step of the reaction involves an attack of the nitrogen atom of 2 at the carbene carbon atom of 1 and a subsequent rearrangement to give N-vinylaminocarbene complexes (E/Z)-4. In a parallel process with different regiochemistry the central carbon of the CCN unit is attached to the carbene carbon to yield π-allyl,σ-complexes (E/Z)-3. Alkylation of 3a with [Et3O]BF4 leads to the formation of a cationic N-(2-propenyl)-aminocarbene complex 6a. Protonation of 4 with trifluoroacetic acid results in a ring contraction to give the four-membered metallacycles 7. X-ray data are reported for prototypes (Z)-4c and 6a.
    Additional Material: 2 Ill.
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  • 14
    ISSN: 0009-2940
    Keywords: Bismuth subhalides ; Band structure and electrical conductivity of Bi6Cl7 ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The methods of preparation for Bi8(AlCl4)2 and Bi6Cl7 have been improved and the single crystal structures for these cluster compounds re-investigated and re-interpreted. In addition, conductivity measurements and band structure calculations using the tight-binding approximation have been performed on Bi6Cl7 and related subvalent bismuth halides. - Bi8(AlCl4)2 consists of isolated AlCl4- anions and rather undistored square-antiprismatic Bi82+ clusters with an average Bi-Bi distance of 3.10 Å. Relatively short intercluster Bi-Bi contacts of 3.90 Å suggest weak bonding interactions between the Bi82+ units. In contrast, the structure determination of Bi6Cl7 implies that this structure should be regarded as being composed of discrete Bi95+ clusters and a polymeric BiIII-Cl anionic lattice including infinite, distorted α1[Bi2Cl24+] chains. According to the experimental and theoretical results, the Bi6X7 (X = Cl, Br) family of subvalent bismuth halide compounds are anisotropic semiconductors along the crystallographic c axis. The conductivity is mediated by the onedimensional α1[Bi2Cl24+] chains. These are interconnected with the Bi95+ clusters, which are acting as electron reservoirs. The related BiX (X = Br, I) family of subvalent bismuth halides are shown to be anisotropic semiconductors in the crystallographic b direction.
    Additional Material: 8 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 655-664 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactive E=C (p—p) π Systems, XIV.  -  Synthesis and Structure of Phosphaalkenes of the Type F3CP=C(F)NR2Perfluoro-2-phosphapropene 1reacts quantitatively with secondary amines R2NH in the molar ratio of 1:2 at temperatures between -120 and -40°C to give (trifluoromethyl)phosphaalkenes of the type F3CP=C(F)NR2 R = Me (2), Et (3), i-pr (4); NR2 = pyrrolidino (5), piperidino (6), 2-methylpiperidino (7, 3-methylpiperidino (8), N-methylanilino (9). Diphenylamine does not react in the same way even at room temperature. The same products are obtained by teh reaction of (CF3)2PH with R2NH and R2NH/NEt3, respectively, in molar rations of 1:3 or 1:1:2. The new compounds 4-9 just as 2 and 3 are stable at room temperature and without exception have Z configuration. The X-ray structure analysis of 1-(dimethylamino)- 1,3,3,3-tetrafluoro-2-phospha-1propene (2) proves the participation of the lone pair on nitrogen in stabilizing the system. The lattice of 2 contains C4H6F4NP molecules with an almost planar CP=C(F)NC2 skeleton. The PC bond distance amounts 1.744(2) Å, the CN bond [1.311(2)Å] is 0.16Å shorter than CN single bonds in amines suggesting a bond order near 2. The reaction of 2With Cr(CO)5(THF) yields the complex Cr(CO)5[F3CP=C(F)NMe2] (10) with P-coordination. In the crystal structure of 10 the CN distance of the coordination. In teh crystal structure of 10 the CN distance of the coordinated ligand is somewhat smaller (1.29 Å) and is slowly transformed to give 2 and the binuclear complex [Cr(CO)5]2F3CP=C(F)NMe2 (11)
    Notes: Perfluor-2-phosphapropen 1reagiert mit sekundären Aminen R2NH im Molverhältnis 1:2 bei Temperaturen zwischen -120 und -40°C quantitativ zu (Trifluormethyl) phosphaalkenen des typs F3CP=C(F)NR2 [R = me(2), Et (3), i-Pr (4); NR2 = Pyrrolidino (5), Piperidino (6), 2-methylpiperidino (7), 3-Methylpiperidino (8), N-Methylanilino (9)]. diphenylamin Setzt sich selbst bei Raumtemperatur nicht in analoger Weise um. Zu den Gleichen Produkten gelangt man durch Umsetzung von (CF3)2PH mit R2NH bzw. R2NH/NEt3 im Molverhältnis 1:3 bzw. 1:1 bzw. 1:1:2. Die neuen Verbindungen 4-9 sind wie 2 und 3 bei Raumtemperatur beständig and besitzen ausnahmslos die Z-Konfiguration. Die Röntgenbeugungsanalyse des 1-(Dimethylamino)-1,3,3,3-tetrafluor-2-phospha-1-propens (2) beweist die beteiligung des freien Elektronenpaars am Stickstoff an der Stabilisierung des Systems. Das Gitter von 2. enthält C4H6F4NP-Moleküle mit fast planarem CP=C(F)NC2-Gerüst. Der PC-Bindungsabstand beträgt 1.744 (2) Å, der CN-Abstand ist mit 1.311(2)Å 0.16Å Kürzer als die CN Einfachbindungen in Aminen und zeigt eine Bindungsordnung nahe 2 an. Die Umsetzung von 2Mit Cr(CO)5(THF) liefert den Komplex CR(CO)5[F3PC=C(F)NMe2] (10) mit P-Koordination. IN der Kristallstruktur von 10ist der CN-abstand des Koordinierten Liganden Geringfügig über (1.29 Å), der PC-Abstand deutlich gröβer (1.80Å) als in 2.10 wandelt sich bei 25°C unter Freisetzung von 2 langsam in den Zweikernkomplex [cr(CO)5]2F3CP=C(F)NMe2 (11) um.
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  • 16
    ISSN: 0009-2940
    Keywords: Methylcarbene complexes of chromium and tungsten ; Cyclohexadienyl tricarbonyliron, carbene derivatives of ; Cycloheptadienyl tricarbonyliron, carbene derivatives of ; Cycloheptatrienyl, carbene derivatives of ; Enol ether, elimination from carbene complexes ; Spirocyclopropanes, elimination from carbene complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 71[1].  -  Methylcarbene Complexes of Chromium and Tungsten with Cycloheptatrienyl-, Cyclohexadienyl[Fe(CO)3]- and Cycloheptadienyl[Fe(CO)3] SubstituentsMethylcarbene complexes LnM=C(OEt)CH3 1 [LnM = (CO)5Cr, (CO)5W] react with tropylium tetrafluoroborate (2a) or coordinated olefins of [C6H7Fe(CO)3]BF4 (2c), [C7H9Fe-(CO)3]BF4 (2d), and [C7H7Fe2(CO)6]BF4 (2d) in the presence of Et3N to give complexes LnM=C(OEt)CH2R 3a-e and LnM=C(OEt)CHR2 7a-d by substitution of one or two α-hydrogen atoms. The trimetallic WFe2 carbene complexes 7c, d derived from 1b with 2c, d form three stereoisomers each, which are fully characterized spectroscopically, (R*,R*,S*)-7c additionally also by an X-ray structure analysis, Ligand elimination from 3 and 7 may involve a-and/or β-hydrogen transfer reactions: Thus enol ethers (Z/E)-6 are eliminated from α-monosubstituted methylcarbene complexes 3a, c, d in yields of 62-90% by a pyridine-induced transfer of an α-hydrogen to the carbene carbon atom; with increasing steric demand of R the elimination of the (Z) isomer (Z)-6 from 3 is favoured over the formation of the (E) isomer (E)-6. The enol ether 10 becomes a minor side product in the pyridine-induced ligand elimination from α-disubstituted complexes 7a, b. In these cases the spirocyclopropane 8 is formed as the main product (60-82%) besides the 4,5-homotropylidene 9 by a conformationally directed β-hydrogen transfer reaction.
    Additional Material: 1 Ill.
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  • 17
    ISSN: 0009-2940
    Keywords: Dinuclear palladium(II) complexes ; Bis(1-methylimidazol-2-yl) ketone ; Pyridine-2-thione ; Pyrimidine-2-thione ; 4-Imidazoline-2-thione, 1-methyl- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three novel dinuclear palladium(II) complexes with the chelating ligand bis(1-methylimidazol-2-yl) ketone (bmik) as well as pyridine-2-thiolate (pyt), pyrimidine-2-thiolate (pymt), and 1-methylimidazole-2-thiolate (meimt) as bridging secondary ligands were prepared by reactions of diaqua[bis(1-methylimidazol-2-yl) ketone]palladium(II) nitrate with the ligands in aqueous solution. The thiolates bridge the two metal atoms in the μ-N,S mode. The structures of the following compounds were analyzed by single crystal X-ray diffraction: Bis(μ-pyridine-2-thiolato-N,S)-bis{[bis(1-methyl-imidazol-2-yl) ketone]palladium(II)}nitrate [Pd2(bmik)2-(pyt)2](NO3)2 · 5 H2O (1), bis(μ-pyrimidine-2-thiolato-N1,S)- bis{[bis(1-methylimidazol-2-yl) ketone]palladium(II)} nitrate [Pd2(bmik)2(pymt)2](NO3)2 · 5 H2O (2), and bis(μ-1-methyl-imidazole-2-thiolato-N3,S)-bis{[bis(1-methylimidazol-2-yl) ketone]palladium(II)} nitrate [Pd2(bmik)2(meimt)2](NO3)2 · 4.5 H2O (3). In the cases of 1 and 3 the bridging thiolate ligands show head-to-head orientation. For complex 2 a head-to-tail orientation of the pyrimidine-2-thiolates was found. The metal-metal distances vary from 2.963 Å in complex 3 and 2.915 Å in 1 to the shortest of 2.886 Á in 2. In addition to the X-ray crystallography the three compounds were characterized by 1H-NMR and IR spectroscopy.
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  • 18
    ISSN: 0009-2940
    Keywords: Selenium ; Fluorine ; Amides ; Cleavage reactions ; Cycloadditions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(trifluoromethylketiminoalkyl)diselanes [SeC(=NR)CF3]2 (6) [R = Me (a), iPr (b), tBu (c)] have been prepared in high yields (55-70%) by reaction of the diselane (SeC2F5)2 (2) with RNH2. However, the analogous reaction of 2 with secondary amines, R2NH, results in the cleavage of the Se-Se bond and leads to the N,N-dialkyl-2,2,2-trifluoroselenoacetamides Se=C(NR2)CF3 (7) [R = Me (a), iPr (b)]. Cleavage of 6a-6c with Me3SnH affords the selenoamides Se=C(NHR)CF3 (9) and the corresponding stannylselanes Me3SnSeC(=NR)CF3 (10) [R = Me(a), iPr (b), tBu (c)]. Selenoamides 7 and 9 can also be prepared from pentafluoroethylselenol HSeC2F5 (3), Se=C(F)CF3, (1) or its polymer [SeC(F)CF3]n (4) and primary or secondary amines. N,N-dialkyl-2-methyl-3-fluoro-4,4,4-trifluoroselenoacrylamides Se=C(NR2)C(Me)=C(F)CF3[R = Et (13a), iPr (13b)] are prepared in moderate yields under mild conditions by treating either trifluoromethylselenocarbonyl fluoride (1) or its polymer [SeC(F)CF3]n with 1-dialkylamino-1-propynes. The reaction proceeds by [2 + 2] cycloaddition and stereospecific electrocyclic ring-opening, yielding, with respect to the resulting C=C double bond, the E isomer as the only product. The molecular structures of 7b, 9a and 13b show the typical features of selenoamides with C(Se)-N bond shortening and C-Se bond elongation due to π interaction of the N lone pair with the C=Se double bond. The observed perpendicular orientation of the selenoamide and the alkene units of 13b prevents π delocalization.
    Additional Material: 4 Ill.
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  • 19
    ISSN: 0009-2940
    Keywords: Cyclopentadienes, synthesis of ; [3 + 2] Cycloadditions of 1-metalla-1,3-dienes and alkynes ; 1-Metalla-1,3,5-trienes of tungsten, cyclization to cyclopentadiene complexes ; η1-Cyclopentadiene tungsten complexes ; Aminocarbene complexes of chromium and tungsten ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 54.  -  Cyclopentadienes from 1-Metalla-1,3-dienes and Alkynes by Cyclization of Intermediate 1-Metalla-1,3,5-trienes (Metal = Tungsten)We report on first examples of the formation of cyclopentadienes from a 1-metalla-1,3-diene LnM=C-C=C [LnM = W(CO)5] and an alkyne in [3 + 2] cycloaddition multistep reactions. In a first step the alkyne Et2N-C=C-Me (2) adds to the 1-metalla-1,3-diene (CO)5W = C(OEt)-CH=CHPh (1b) to give 1-metalla-1,3,5-trienes (CO)5W=C(NEt2)-CMe=C(OEt)-CH=CHPh (3b) and (CO)5W=C(OEt)-CH=C(NEt2)-CMe=CHPh (4b). In a second step 3b cyclizes to thecyclopentadiene complex 5, which has an η1 ylide-type structure as established by an X-ray analysis. Hydrolysis of 5 leads to the formation of a 3-aminocyclopentenone 7. The 1-metalla-1,3,5-triene 4b yields a cyclopentadiene complex 8. In contrast to 5 the carbon skeleton of 8 has a connectivity different from that of the C3 unit of the 1-metalla-1,3-diene 1.
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  • 20
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 411-414 
    ISSN: 0009-2940
    Keywords: Phosphaalkyne, amino- ; [3 + 2] Cycloaddition ; 1,2,4-Diazaphospholes ; 1,2,3-Diazaphospholes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactive E = C(p - p)π Systems, XXXII[1].  -  First Representatives of Amino-Substituted 1,2,4-Diazaphospholes(Diisopropylamino)phosphaethyne iPr2N - C≡P reacts at 20° C in a [3 + 2] cycloaddition with (trifluoromethyl)diazomethane (2a) or methyl diazoacetate (2b) to yield a mixture of the corresponding regioisomers 1H-1,2,4-diazaphospholes (5a or 5b) and 1H-1,2,3-diazaphospholes (6a or 6b) in quantitative yields (isomer ratio: 5a/6a = 2:1; 5b/6b = 4:1). X-ray diffraction studies on 5a and 5b indicate a delicate charge balance in the bonding system of 1H-1,2,4,σ2-diazaphospholes under the influence of the exocyclic push/pull substituents iPr2N and CF3 or CO2Me, respectively.
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