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  • 21
    Digitale Medien
    Digitale Medien
    Synthese und Struktur des Mangan(II)-L-aspartat-trihydrats, Mn(L-Asp) · 3H2O (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 795-797 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Synthesis and Structure of Manganese(II) L-Aspartate Trihydrate, Mn(L-Asp)· 3H2OManganese L-aspartate chloride, Mn(L-AspH)Cl, has been prepared from equimolar quantities of MnCl2 and Mn(L-AspH)2 in water. This material can be converted into the title compound by treatment with aqueous KOH, and crystallized as a trihydrate from solutions kept at pH = 7.85. The compound has been characterized by elemental analysis and by single crystal X-ray structure determination. In the crystal, the aspartate dianion functions as a facially tridentate ligand to the Mn(II) center whose octahedral coordination sphere is completed by two water molecules and a carboxylate oxygen atom from a neighboring complex in trans position to the amino group. The stereochemistry of this coordination mode is different from that in the analogous magnesium compound, but similar to that in the cobalt(II) and zinc(II) analogues. The third water molecule is a hydrogen-bonded crystal water.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19881210427
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  • 22
    Digitale Medien
    Digitale Medien
    Arsen(III)-, Antimon(III)- und Bismuth(III)-halogenid-Komplexe des [2.2.2]Paracyclophans: Vom lockeren van-der-Waals-Addukt zu stark gerichteten π-Komplexen mit zwei- und dreifacher externer η6-Koordination (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1089-1093 
    Details
    ISSN: 0009-2940
    Schlagwort(e): [2.2.2]Paracyclophane ligand ; (η6)π Complexes ; Arsenic(III) complexes ; Antimony(III) complexes ; Bismuth(III) complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Arsenic(III), Antimony(III), and Bismuth(III) Trihalide Complexes of [2.2.2]Paracyclophane: From Weak van der Waals Coordination to Strongly Directional π Complexation with Single or Double External η6 Coordination[2.2.2]Paracyclophane forms the adducts C24H24·AsCl3 (1), C24H24·(SbCl3)2·1/2 C6H6 (2), and C24H24·(BiCl3)3·C6H6 (3). For solutions in polar solvents NMR spectra indicate extensive dissociation and/or fluxionality. In the crystals adduct 1 features a weak addition of the AsCl3 molecule to one open side of a paracyclophane molecule with long intermolecular contacts approaching C3v symmetry. - Crystalline 2 shows SbCl3 coordination to two of the benzene rings of the hydrocarbon in a quasi-centered η6 mode, while one of the benzene rings remains uncoordinated. Chlorine-bridging between antimony atoms leads to tetrameric units (SbCI3)4 in the lattice. - In the bismuth compound 3 each benzene ring of the hydrocarbon is engaged in centroid (η6)π complexation, with the BiCl3 units crosslinked by chlorine bridges. The average of the Bi-ring distances (3.08,2.98, and 2.99 Å) is shorter than for the Sb-ring distances in 2 (3.047 and 3.050 Å), indicating stronger bonding. The crystal benzene is not coordinating.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19911240516
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  • 23
    Digitale Medien
    Digitale Medien
    Metal Bonding by Amino Acids: Preparation and Crystal Structures of Calcium Bis-L-pyroglutamate and Lithium L-Pyroglutamate (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1083-1087 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Calcium bis-L-pyroglutamate ; Lithium L-pyroglutamate ; Pyroglutamate coordination and conformation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Calcium bis-L-pyroglutamate and lithium L-pyroglutamate are prepared by reaction of the metal hydroxides with L-pyroglutamic acid in aqueous solution. In the solid state calcium bis-L-pyroglutamate adopts a layer structure, built up by sixteen-membered rings consisting of four L-pyroglutamate ligands bridging four calcium centers by their carboxylate groups. All three oxygen donors of the L-pyroglutamate ligands are attached to metal centers. The calcium atom lies at the center of a slightly distorted octahedron formed by four carboxylate oxygens and two amide oxygen atoms. Lithium L-pyroglutamate also features a layer structure. All three oxygen donors of the L-pyroglutamate ligand have contacts with metal atoms. The coordination sphere of the lithium atom is a slightly distorted tetrahedron consisting of three carboxylate oxygen atoms and one amide oxygen atom. The investigation of aqueous solutions of the compounds by multinuclear NMR (1H, 13C, 17O) indicates extensive electrolytic dissociation in dilute solutions.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19911240515
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  • 24
    Digitale Medien
    Digitale Medien
    Metal Binding by Amino Acids: Preparation and Crystal Structures of Lithium, Sodium, and Potassium Hydrogen Bis-L-pyroglutamate (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1829-1834 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hydrogen bis-L-pyroglutamates, lithium, sodium, potassium ; Pyroglutamate coordination and conformation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Lithium, sodium and potassium hydrogen bis-L-pyroglutamate [Li(L-pGlu)(L-pGluH)], [Na(L-pGlu)(L-pGluH)] and [K(L-pGlu)(L-pGluH)], respectively, have been prepared by reaction of aqueous solutions of the metal hydroxides with L-pyroglutamic acid in the molar ratio 1:2, or in methanol. Crystalline samples of the salts could be obtained by slow evaporation of solutions of the salts in methanol. In the solid state, Li(L-pGlu)(L-pGluH) adopts a chain structure with the lithium atoms arranged in double strands. Adjacent metal centers are bridged by the carboxylate groups of the L-pGlu- ligands. The L-pGluH ligands are attached to the metal centers through the amide oxygen atoms. Na(L-pGlu)(L-pGluH) forms a three-dimensional coordination polymer with two half-occupied sodium positions, one L-pGlu- and one L-pGluH ligand in the asymmetric unit. The carboxyl and carboxylate groups of the L-pGluH and the L-pGlu- ligands are bridging the sodium centers, giving rise to eight-membered rings, which consist of two sodium atoms, a carboxyl and a carboxylate group. The hydrogen atoms of the carboxyl group of the L-pGluH ligands are involved in strong hydrogen bonds between a carboxyl and an adjacent carboxylate oxygen atom. K(L-pGlu)(L-pGluH) adopts a layer structure with strands of potassium atoms. The metal centers are connected through bridging carboxyl and carboxylate groups of the L-pGluH and L-pGlu- ligands, respectively. The structure features eight-membered ring units comparable to those observed for Na(L-pGlu)(L-pGluH), again with the hydrogen atom of the carboxyl group engaged in a strong transannular hydrogen bond. The amide oxygen atoms of the L-pGlu- and the L-pGluH ligands are coordinated to the metal centers of adjacent coordination chains. The results of 1H- and 13C—NMR investigations of aqueous solutions of the compounds indicate extensive electrolytic dissociation in dilute solutions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19921250808
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  • 25
    Digitale Medien
    Digitale Medien
    New Organophosphorus Ligands: Cyclopropanation and Other Reactions of Cumulenes Bearing Diphenylphosphanyl Substituents (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 365-371 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cumulenes ; Butadienes ; Vinylcyclopropane ; Vinylidenecyclopropane ; Bicyclopropyl, phosphanyl-substituted ; Cyclopropanation ; Phosphane ligands ; Phosphane chalcogenides ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Hydrophosphorylation of 1,4-bis(diphenylphosphanyl)butadiyne with diphenylphosphane leads to the butadiene (Ph2P)2C=CH—CH=C(PPh2)2 (1). Treatment of 1 with dimethylsulfonium methylide gives the vinylcyclopropane (Ph2P)2C=CH—CH(CH2)C(PPh2)2 (2). Compound 2 reacts with aqueous hydrogen peroxide, elemental sulfur, or selenium to afford the tetrachalcogenides (Ph2XP)2C=CH—CH(CH2)C(PXPh2)2 with X = O (3), X = S (4), X = Se (5), respectively. While the tetraphosphane 1 and the vinyl-cyclopropane compound 2 cannot be converted into a bis-(cyclopropyl) compound with an excess of Me2S=CH2, the tetrasulfide 4 readily affords a mixture of (1R,1′R)-/(1S,1′S)-and meso-2,2,2′,2′-tetrakis(diphenylthiophosphinyl)-1,1′-bicyclopropyl (6, 7) in good yield. Treatment of 1,1,4,4-tetrakis-(diphenylphosphanyl)butatriene with dimethylsulfonium methylide leads to the vinylidenecyclopropane (Ph2P)2C=C=C(CH2)C(PPh2)2 (8). Compound 8 is converted into its tetrasulfide (Ph2SP)2C=C=C(CH2)C(PSPh2)2 (9) by treatment with elemental sulfur. The crystal structures of 1, 2, 4, 7, and 8 have been determined by single-crystal X-ray diffraction.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19951280408
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  • 26
    Digitale Medien
    Digitale Medien
    Strukturvergleich von H2C = C(PPh2)2 und Ph3P = C(PPh2)2: Ein Beitrag zur Problematik der P = C-Doppelbindung in Yliden (1984)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2322-2327 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Structure Comparison of H2C = C(PPh2)2 and Ph3P = C(PPh2)2. A Contribution to the P = C Double Bond Problem in YlidesThrough a structure analysis of H2C = C(PPh2)2 (1) the conformation-determining effect of the C = C double bond could be compared with that of the P = C double bond in the ylide Ph3P = C-(PPh2)2 (A). Single crystal X-ray diffraction of 1 showed that indeed analogous conformations of the Ph2P groups relative to the basic plane of the molecule are present in the solid. However, the directing influence is much weaker in 1 than in A, and in solution even at -75°C no non-equivalence of the P-atoms is detectable by 31P NMR spectroscopy. The restricted rotation previously found for A is therefore attributed to the gauche effect of the lone pairs of electrons at PIII and the ylidic C atom. According to bond distances, no π-interactions C = P can be diagnosed in 1, while significant contributions of this type seem to be valid for A.
    Notizen: Durch die Strukturanalyse von H2C = C(PPh2)2 (1) konnte der konformationsbestimmende Effekt der C = C-Doppelbindung mit dem der P = C-Doppelbindung im Ylid Ph3P = C(PPn2)2 (A) verglichen werden. Die Kristallstrukturanalyse von 1 ergab, daß im festen Zustand wirklich ähnliche Konformationen der Ph2P-Gruppen relativ zur Grundebene des Moleküls vorliegen. Die dirigierende Wirkung ist jedoch nicht so stark wie im Ylid, so daß in Lösungen 31P-NMR-spektroskopisch auch bei - 75°C noch keine Nichtäquivalenz der P-Atome feststellbar ist. Die Rotationsbehinderung in A wird auf den gauche-Effekt der freien Elektronenpaare an PIII und Ylid-C-Atom zurückgeführt. Nach Abstandskriterien entfallen bei 1 auch π-Wechselwirkungen C = P, während sie bei A offenbar erhebliche Beiträge leisten.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19841170705
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  • 27
    Digitale Medien
    Digitale Medien
    Olefin- und Cyclopropan-Aktivierung durch geminale Phosphonium-Zentren (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3105-3113 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Olefin and Cyclopropane Activation Through Geminal Phosphonium CentresComplete quaternization of vinylidenebis(diphenylphosphane) (1) with CH3I or CH3OSO2F yields the diquaternary salts 2a,b, whose olefinic double bond is strongly electrophilic through the activation by two geminal phosphonium centres. Accordingly, addition of methanol or ethanol to 2a,b leads to β-alkoxy-substituted double phosphonium salts 9a-i. The structure of one of these products (9a: X=I, R=CH3) was elucidated by single crystal X-ray diffraction analysis. Spectroscopic data are provided for the remaining compounds. - Treatment of triphenylphosphonium cyclopropylide (5) with chlorodiphenylphosphane gives the gem-phosphinosubstituted salt 6, which can be quaternized with CH3OSO2F to yield a bis-phosphonium salt (7a,b). A symmetrical homologue 7c is formed from cyclopropylidenebis(diphenylphosphane) (8) and CH3OSO2F. In 7a-i the cyclopropane cycle is also clearly activated. Ring cleavage occurs with alcohols leading to γ-alkoxylated salts 10a,b.
    Notizen: Die erschöpfende Quartärisierung von Vinylidenbis(diphenylphosphan) (1) mit CH3I oder CH3OSO2F liefert Diquartärsalze 2a,b, deren olefinische Doppelbindung durch die beiden Phosphonium-Zentren stark elektrophil aktiviert ist. Die Addition von Methanol oder Ethanol an 2a,b liefert entsprechend die β-alkoxysubstituierten Doppelphosphonium-Salze 9a-i. Die Struktur eines dieser Produkte (9a: X=I, R=CH3) wurde durch eine Einkristall-Röntgenbeugungsanalyse gesichert, für die übrigen liegen spektroskopische Daten vor. - Triphenylphosphoniumcyclopropylid (5) ergibt mit (C6H5)2PCl das geminal phosphinosubstituierte Salz 6, das durch CH3OSO2F zum Bisphosphonium-Salz quartärisiert werden kann (7a,b). Ein symmetrisches Homologes 7 c entsteht aus Cyclopropylidenbis(diphenylphosphan) (8) und CH3OSO2F. In 7a-i ist der Cyclopropan-Cyclus ebenfalls deutlich elektrophil aktiviert. Mit Alkoholen tritt Ringspaltung ein, die hier zu γ-alkoxylierten Salzen 10a,b führt.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19851180809
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  • 28
    Digitale Medien
    Digitale Medien
    Übergangsmetall-Carben-Komplexe, CXXXVI. Reaktionen kationischer Carbin-Komplexe des Mangans mit Carbonylmetallaten (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3311-3319 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Transition Metal Carbene Complexes, CXXXVI. Reactions of Cationic Carbyne Complexes of Manganese with Carbonyl MetalatesThe first carbene complexes (5, 6), with a transition metal α-bonded to the carbene carbon atom, are obtained by reaction of dicarbonyl(phenyl, ferrocenylcarbyne)(methylcyclopentadienyl)manganese tetrachloroborate (1, 2) with Na[Co(CO)4]. Analogous reaction with K[Mn(CO)5] leads to the isomeric ketenyl complexes (3, 4) via rearrangement of the carbene to the ketenyl complex. Properties and spectra are reported. An X-ray structure analysis of MeCp(CO)2Mn[μ-C(CpFeCp)CO]Mn(CO)4(Mn - Mn) (4) confirms the presence of a bridging ketenyl ligand.
    Notizen: Durch Umsetzung von Dicarbonyl(phenyl, ferrocenylcarbin)(methylcyclopentadienyl)mangan-tetrachloroborat (1, 2) mit Na[Co(CO)4] erhält man erstmals Carben-Komplexe mit einem Übergangsmetall in α-Stellung zum Carben-Kohlenstoffatom (5, 6). Die analoge Reaktion mit K[Mn(CO)5] führt zu isomeren Ketenyl-Komplexen (3, 4), die durch Umlagerung von Carben- zu Ketenyl-Komplex entstehen. Eigenschaften und Spektren werden beschrieben. Die Röntgenstrukturanalyse von MeCp(CO)2Mn[μ-C(CpFeCp)CO]Mn(CO)4-(Mn - Mn) beweist das Vorliegen eines verbrückenden Ketenyl-Liganden.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19851180830
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  • 29
    Digitale Medien
    Digitale Medien
    Lanthanoiden-Komplexe, II. Tris(tert-butylcyclopentadienyl)neodym, -dysprosium und -thulium. Kristall- und Molekülstruktur von Bis(tert-butylcyclopentadienyl)-hydroxidoneodym und -dysprosium (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2391-2397 
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    ISSN: 0009-2940
    Schlagwort(e): Lanthanides ; Cyclopentadienyl ligand ; Neodymium complexes ; Dysprosium complexes ; Thulium complexes ; Thermochemistry ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Complexes of the Lanthanides, II[1]. - Tris(tert-butylcyclopentadienyl)neodymium, -dysprosium, and -thulium. Crystal and Molecular Structure of Bis(tert-butylcyclopentadienyl)hydroxidoneodymium and -dysprosiumNdCl3, DyCl3, and TmI3 (1a-c) react with the potassium salt K(tBuCp) (2) of tert-butylcyclopentadiene in THF to yield the sublimable homoleptic tris(tert-butylcyclopentadienyl) complexes of formula Ln(tBuCp)3 (3a-c). The thermal behavior makes these compounds potential precursors for chemical vapour deposition techniques (MOCVD).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19921251111
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  • 30
    Digitale Medien
    Digitale Medien
    Synthesis of the Hexakis[(triphenylphosphane)gold(I)]methanium(2+) Cation from Trimethylsilyldiazomethane; Crystal Structure Determination of the Tetrafluoroborate Salt (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 111-114 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Gold clusters ; Silyldiazomethane ; Auration ; Interstitial carbon atom ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A new synthetic route to the bis(tetrafluoroborate) salt of the hexakis[(triphenylphosphane)gold(I)]methanium dication has been opened up through the reaction of trimethylsilyldiazomethane and tris[(triphenylphosphane)gold(I)]oxonium tetrafluoroborate in dichloromethane. Yields are close to 65% if the reaction is carried out in the presence of triethylamine as a base. The process is a sequence of desilylation, deprotonation and deazotation reactions at the carbon function of the diazomethane, as shown by the detection of intermediates. The crystal structure of the title compound (with three equivalents of crystal dichloromethane) has been determined in a single-crystal X-ray study. The dication has no crystallographically imposed symmetry, but the core is a distorted, carbon-centered octahedron of gold atoms. This result confirms the data from previous structural studies of salts with other anions and interstitial solvents.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300118
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