ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 219. (Di-tert-butylphosphanylimino)(2,2,6,6-tetramethylpiperidino)boran: ein BNP-1,3-“Dipol” (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1995-2002 
    Details
    ISSN: 0009-2940
    Keywords: Boranes, amino(phosphanylimino)- ; Phosphaborolines ; Iminophosphoranes ; 1,3,2,5-Oxazaphosphaboroles ; 1,3,4,2-Thiazaphosphaboroles ; 1,3,4,2-Diazaphosphaboroles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 219[1]. - (Di-tert-butylphosphanylimino)(2,2,6,6,-tetrametylpiperidino)borane: a BNP 1,3-„Dipole”In contrast to amino-imino-boranes R2N-BN-R', which are susceptible to [2 + 2] cycloadditions, the amino(phosphanyl-imino)borane 2 [R = P(tBu)2] performs [3 + 2] cycloadditions with heteroallenes X≡C≡Y or nitriles to yield the novel five-membered heterocycles 3a-g, 6, 7, and 8. The reactions of 2 are dominated by the phosphorus atom as the nucleophile attacking the carbon atom in X≡C≡Y and R-CN, respectively. The driving force for the formation of the new heterocycles is obviously provided by the formation of an iminophosphorane structure and a three-coordinated environment at the boron atom. The X-ray-structures of 3a, 3c, 3e, and 3g demonstrate planer heterocyclic rings.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Direct Synthesis of Organometallics, IVPart III: Ref.[1].. The Mechanism of the Activation of Aromatic Hydrocarbons with Lithium Atoms: Spectroscopic Results and Their Ab initio Interpretation (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 1369-1371 
    Details
    ISSN: 0009-2940
    Keywords: C—H bond activation ; Lithium atoms ; Mechanism ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the presence of THF, lithium atoms are known to be able to activate benzene derivatives under cryogenic reaction conditions. This synthesis affords solid lithium hydride and ring-metalated products selectively. For the determination of the reaction mechanism, the cocondensation reaction was repeated on a reduced scale in a 77-K cryostate, which allowed the measurement of UV/Vis and IR spectra. The spectroscopic results exclude any generation of free electrons; their interpretation suggests that small solvated lithium clusters activate the hydrocarbon bonds. A model reaction was developed by using the spectroscopic results and ab initio calculations. Thus, benzene was added to a Li2 cluster, which reduces the carbon-hydrogen bond to the phenyl anion and hydride on the surface without the formation of free radicals. In the last step the intermediate mixed organolithium species dismutate to solid lithium hydride and phenyllithium.The reduction process on the cluster surface is facilitated by coordinating THF to the lithium, which results in a higher redox potential. The complete mechanism is discussed in the terms of geometries of the intermediates and reaction enthalpies in connection with the experimental values. Thus, a distinct new reaction pathway for a substitution on the benzene ring is established.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961291109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The Reaction of RLi Species with CO and Isonitriles: IR Spectroscopic Investigations in Liquid Xenon and Ab-Initio Calculations of the Intermediates (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1051-1053 
    Details
    ISSN: 0009-2940
    Keywords: Carbonyllithium compounds ; Acyllithium compounds ; IR spectroscopy in liquid xenon ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solutions of alkyl- or aryllithium compounds were treated with CO or tBu-NC in liquid xenon (LXe) at low temperature. Carbonyllithium compounds, acyllithium and the corresponding isolobal isonitrile products were characterized by IR spectroscopy for the first time. The structures, energies and characteristic IR frequencies of the intermediates were calculated by using ab-initio methods and discussed with the experimental values.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281015
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Infrarotspektroskopischer Nachweis von monomerem HGaCl2 in festem ArgonProfessor Joseph Grobe zum 60. Geburtstage am 2. November 1991 gewidmet (1991)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 605 (1991), S. 35-41 
    Details
    ISSN: 0044-2313
    Keywords: Gallium hydrogen dichloride ; matrix isolation ; IR spectra ; normal coordinate analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Infrared Spectroscopic Evidence for Monomeric HGaCl2 in Solid ArgonMolecular HGaCl2 is found in a matrix between the hightemperature molecule GaCl and HCl. A structure analogous to that of phosgene can be derived from the isotopical shifts (H/D, 69Ga/71Ga and 35Cl/37Cl) within the IR spectra. The normal coordinate analysis results for the GaCl force constant a value of 2.52 mdyn/Å and for the GaH force constant a value of 2.38 mdyn/Å.
    Notes: Molekulares HGaCl2 entsteht in einer photochemischen Reaktion aus dem Hochtemperaturmolekül GaCl und HCl in festem Argon. Die Lage der IR-Absorptionen und die H/D-, 69Ga/71Ga- bzw. 35Cl/37Cl-Verschiebungen weisen auf eine Spezies mit C2v-Struktur hin. Die Normal-koordinatenanalyse liefert für die GaCl-Bindung eine Kraftkonstante von 2,52 mdyn/Å und für die GaH-Kraftkonstante einen Wert von 2,38 mdyn/Å.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19916050104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Selective Activation of Aromatic C - H Bonds with Lithium Atoms at 77 K (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 91-92 
    Details
    ISSN: 0009-2940
    Keywords: C - H bond activation ; Lithum atoms ; Cocondensation ; Aryllithium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the presence of donor bases like THF lithium atoms are able to activate benzene derivatives under cryogenic reaction conditions. Only ring-metalated products and solid lithium hydride are formed selectively. The thermodynamically favored product benzyllithium or biphenyl generated by dimerization of free phenyl radicals are not found. This is one of the very few examples of metal atoms undergoing a C - H activation without further photoexcitation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...