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  • Inorganic Chemistry  (22)
  • General Chemistry  (11)
  • Spectroscopic Data  (5)
  • Agostic Interactions  (1)
  • 1
    ISSN: 1434-1948
    Keywords: Hydrogen bonds ; Indium ; Lithium ; Nitrogen heterocycles ; Zinc ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The lithiation of 2,5-di(tert-butyl)pyrrole (1) yields bis(tetrahydrofuran)lithium 2,5-di(tert-butyl)pyrrolide (2), which is monomeric in solution as well as in the solid state. Due to the coordination number of three for the lithium atom, short Li-O and Li-N bond lengths of 193 pm are observed. The metathesis reaction of 2 with tris(trimethylsilyl)-methylzinc chloride (3) gives colorless bis[tris(trimethyl-silyl)methylzinc] chloride 2,5-di(tert-butyl)pyrrolide (4). The pyrrolide ligand and the chlorine atom bridge the zinc atoms. One of the zinc atoms is bonded to the nitrogen atom of the pyrrolide substituent, while the other bonds to the opposite C-C bond. At 215 pm, the Zn-N bond is very long compared to those in alkylzinc amides, whereas the Zn-C distances lie in the range of Zn-C bond lengths found between zinc and η5-bonded cyclopentadienide ligands. The molecular structures of 1 and of the low-melting THF adduct 1·thf show a similar 2,5-di(tert-butyl)pyrrole molecule, but in the latter case a weak N-H···O bond is observed (N-H 97 pm, O···H 199 pm).
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 522 (1985), S. 83-91 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Amidinocomplexes of Molybdenum (V) and Rhenium (V). Crystal Structure of [Cl4Mo{i-Prop-NC(Cl) N-i-Prop}]Molybdenum pentachloride and rhenium pentachloride, respectively, react with di-isopropylcarbodiimide in CCl4-suspensions forming the monomeric amidino complexes [Cl4M{i-prop-NC(Cl)N-i-prop}] (M = Mo, Re). According to the i.r. spectra the C—Cl-amidino ligand is bonded as a chelate. The molybdenum complex is characterized by an X-ray structure determination. It crystallizes in the tetragonalic space group I41/a with 8 formula units in the unit cell (1538 independent, observed reflexions, R = 0.051) with the lattice constants a = 1119 and b = 2332 pm.
    Notes: Molybdänpentachlorid bzw. Rheniumpentachlorid reagieren mit Di-isopropylcarbodiimid in CCl4-Suspensionen unter Bildung der monomeren Amidinokomplexe [Cl4M{i-Prop-NC(Cl)N-i-Prop}] (M = Mo, Re). nach den IR-Spektren ist der C-Chlor-amidinoligand als Chelat gebunden. Der Molybdänkomplex wurde durch eine röntgenorgraphische Strukturanalyse charakterisiert. Er kristallisiert in der tetragonalen Raumgruppe 141/a mit 8 Formeleinheiten pro Elementarzelle (1538 unabhängige, beobachtete Reflexe, R = 5,1%) mit den Gitterabmessungen a = 1119 und b = 2332 pm.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 525 (1985), S. 143-149 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure of [Cl4P{i-Prop-NC(Cl)N-i-Prop}]The monomeric di-isopropylcarbodiimide complex [Cl4P{i-Prop-NC(Cl)N-i-Prop}] crystallizes in the monoclinic space group C2 with 4 formula units in the unit cell and with the lattice constants a = 1391.2(2), b = 708.6(1), c = 1463.5(2) pm and β = 95.76(1)°. The structure was refined to an R-value of 0.026 (2084 independent, observed reflexions). Main parts of the IR and Raman spectrum of the compound are discussed.
    Notes: Der monomere Di-isopropylcarbodiimidkomplex [Cl4P{i-Prop-NC(Cl)N-i-Prop}] kristallisiert in der monoklinen Raumgruppe C2 mit 4 Formeleinheiten pro Einheitszelle und den Gitterkonstanten a = 1391,2(2), b = 708,6(1), c = 1463,5(2) pm und β = 95,76(1)°. Die Struktur wurde bis zu einem R-Wert von 0,026 verfeinert (2 084 unabhängige, beobachtete Reflexe). Wichtige Abschnitte des IR- und Ramanspektrums der Verbindung werden diskutiert.
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 89 (1977), S. 423-424 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 5
    ISSN: 0009-2940
    Keywords: Lithium ; Zine ; Dibenzylzinc ; Tmeda complexes ; Heteroleptic alkylzinc amide ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of lithium phenyl(trimethylsilyl)methanide with phenyl(trimethylsilyl)methylzinc chloride-tmeda in the presence of tmeda yields the addition product, a bis(tmeda)-lithium dialkylchlorozincate. The elimination of lithium chloride leads to the formation of a tmeda adduct of bis[phenyl-(trimethylsilyl)methyl]zinc. The metathesis reaction of phenyl(trimethylsilyl)methylzinc chloride-tmeda with lithium tris(trimethylsilyl)silylamide allows the isolation of the corresponding heteroleptic tmeda complex of an alkylzinc amide. The metalation of phenyl(trimethylstannyl)methane with butyllithium yields the transmetalation product benzyllithium. From the metathesis reaction of this lithium base with anhydrous zinc(II) chloride in the presence of tmeda, the tmeda adduct of dibenzylzinc crystallizes. The molecular structures of (tmeda)Li—CH(GeMe3)Ph, (tmeda)Zn(CH2Ph)2, (tmeda)Zn[CH(SiMe3)Ph]2, and (tmeda)Zn[CH(SiMe3)-Ph[N(H)Si(SiMe3)3 are reported. Whereas lithium bonds in an η3-fashion, the zinc atom forms a σ(Zn—C) bond. The extremely wide Zn—N—Si angle in (tmeda)Zn[CH(SiMe3)-Ph[N(H)Si(SiMe3)3 of 157° is remarkable.
    Additional Material: 4 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 994-1003 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectroscopic Investigations on DivinylcyclobutanesThe He(I) photoelectron (PE) spectra of cis/trans-1,3-divinylcyclobutane (1,2), cis/trans-1,2-divinylcyclobutanes (3,4), as well as the alkyl-substituted 1,2-divinylcyclobutanes 5-7 have been recorded. The interpretation is based on semiempirical calculations (MINDO/3, MNDO) and calculations using a ZDO-model. In case of 1-4 we determined the conformation of lowest energy by optimization of all geometrical parameters. The orbital energies calculated for this conformation agree very well with the measured vertical ionization potentials.
    Notes: Die He(I)-Photoelektronen (PE)-Spektren von cis/trans-1,3-Divinylcyclobutan (1,2), cis/trans-1,2-Divinylcyclobutan (3,4) sowie der alkylsubstituierten 1,2-Divinylcyclobutane 5-7 werden mit Hilfe semiempirischer Rechnungen (MINDO/3, MNDO) und eines ZDO-Modells interpretiert. Bei 1-4 wurde durch Geometrieoptimierung die anti-bisektierte Konformation in jedem Falle als die mit niedrigster Energie bestimmt. Die Orbitalenergien, die für diese Konformation berechnet werden, ergeben eine gute Übereinstimmung mit den gemessenen vertikalen Ionisationspotentialen.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 2554-2563 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 1,1′-Bicyclobutyl and 1,1′-Bicyclohexyl DerivativesDimeric glycols (2, 3 and 20, 24) are prepared from ethyl 3-oxocyclobutanecarboxylate (1) and 4-substituted cyclohexanone derivatives 9, 10, 23 by low valent titanium reagents. Dimeric olefins (17, 18) were obtained from the cyclohexanones by Barton's thiadiazoline method. Some experiences with cis-protecting groups for the 1,1′-dihydroxy dimers are presented.
    Notes: Aus dem 3-Oxocyclobutancarbonsäure-ethylester (1) und 4-substituierten Cyclohexanonen 9, 10, 23 werden mit niederwertigem Titan die dimeren Glycole 2, 3 bzw. 20, 24 hergestellt, aus den Cyclonexanonen mit Bartons Thiadiazolin-Methode auch die dimeren Olefine 17, 18. Einige Erfahrungen mit den Schutzgruppen zur cis-Fixierung der 1,1′-Dihydroxy-Dimeren werden mitgeteilt.
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  • 8
    ISSN: 0009-2940
    Keywords: Phosphanes ; Bis(silyl)phosphanes ; Tris(silyl)phosphanes ; Phosphanides ; Barium bis(phosphanide) ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Barium bis[bis(trimethylsily)amide] metalates bis(isopropyldimethylsilyl)phosphane (1) to yield nearly quantitatively the corresponding barium bis[bis(isopropyldimethylsilyl)phosphanide] (3). This compound shows a temperature-dependent monomer-dimer equilibrium in toluene solution. Both the isomers were characterized by X-ray crystal structure analyses. The monomeric derivatives precipitate as a tetrakis(tetrahydrofuran) complex with a P-Ba-P bond angle of 139.9°. The barium atoms of the monocyclic, centrosymmetric dimer are pentacoordinated by two tetrahydrofuran molecules, one terminal and two bridging phosphanide ligands. The endo- and exocyclic Ba-P distances with values of 332 and 316 pm, respectively, lie within the characteristic range.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 435-438 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On hydrogenation of the title compound 1 with Pd/C 1,4-diethylbenzene (2) is formed in 95% yield, furthermore 1% of cis- and 2% of trans-1,4-diethylcyclohexane (3 und 4) as well as 2% of 6-ethylspiro[2.5]octane (15) are found. With Pt/C the intermediates 7, 12, 13, and 14 and up to 45% of dispiro[2.2.2.2]decane (17) are identified. 17 is hydrogenated with PtO2 in acetic acid to form 1,1,4,4-tetramethylcyclohexane (19).
    Notes: Bei der Hydrierung der Titelverbindung 1 mit Pd/C entsteht zu 95% 1,4-Diethylbenzol (2), daneben noch ca. 1% cis- und 2% trans-1,4-Diethylcyclohexan (3 und 4) sowie 2% 6-Ethylspiro-[2.5]octan (15). Mit Pt/C wird zusätzlich (bis zu 45%) Dispiro[2.2.2.2]decan (17) gebildet, und man erkennt die Zwischenstufen 7, 12, 13 und 14. Mit PtO2 in Eisessig wird 17 weiter zu 1,1,4,4-Tetramethylcyclohexan (19) hydriert.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 990-993 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of cis-and trans-1,3-DivinylcyclobutaneAt 300°C cis-1,3-Divinylcyclobutane (4) gives butadiene (5) and 4-vinyl-1-cyclohexene (6) as well as trans-1,3-divinylcyclobutane (2) in small quantity. 2 has been synthesized in an independent way and yields the same products as 4. The diradical 3 is considered as an intermediate.
    Notes: cis-1,3-Divinylcyclobutan (4) reagiert um 300°C zu Butadien (5) und 4-Vinyl-1-cyclohexen (6), wobei trans-1,3-Divinylcyclobutan (2) in geringer Menge auftritt. 2 wird unabhängig hergestellt und liefert die gleichen Produkte sowie 4. Das Diradikal 3 wird als Zwischenstufe angesehen.
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