Browsing by Author "Bock, Hans"

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    Photoelectron spectra and molecular properties. 15, The effects of α- and β-silyl substituents on π-systems
    (1972) Mollère, Phillip D.; Bock, Hans; Becker, Gerd; Fritz, Gerhard
    The photoelectron spectra of substituted ethylenes, H 2 C=CHX (X = H, CH 3, SiH 3, CH 2CH 3, CH 2SiH 3) are discussed in the light of results of CNDO-type molecular orbital calculations. The characteristic shifts of the first bands are explained in terms of a qualitative model for the substituent effects of α- and β-silyl groups upon π-systems.
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    Photoelectron spectra and molecular properties. 20, Dimethyl ether, methoxysilane, and disiloxane
    (1973) Bock, Hans; Mollère, Phillip D.; Becker, Gerd; Fritz, Gerhard
    The photoelectron (PE) spectra of methyl and silyl ethers are assigned and correlated on the basis of CNDO/2-SCF-MO calculations. The dynamic behavior of the individual orbitals is discussed in terms of electronic and geometric perturbations of the ether system.
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    Photoelectron spectra and molecular properties. 21, Dimethyl sulfide, methyl silyl sulfide, and disilyl sulfide
    (1973) Mollère, Phillip D.; Bock, Hans; Becker, Gerd; Fritz, Gerhard
    The photoelectron spectra of methyl and silyl sulfides are assigned on the basis of modified CNDO-SCF-MO calculations. The orbital sequence (2b1, 4a1, 3b2) is found to be independent of conformation. The static geometry of the sulfides is in keeping with a smaller charge shift to sulfur accompanying the carbon-silicon exchange. Comparison of the results wit those of the analogous ethers lends support to the previous assignment of the latter.
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    Photoelectron spectra and molecular properties. 30, Pi-interactions in H3Si- and H3C-substituted acetylenes
    (1974) Ensslin, Walther; Bock, Hans; Becker, Gerd
    The photoelectron (pe) spectra of mono- and disubstituted silyl- and methylacetylenes are assigned by comparison with the corresponding ionization potentials of acetylene, disilane, and ethane. The observed π splittings can be rationalized within a parameterized hyperconjugation model. Calculations using a modified CND0/2 procedure with and without inclusion of 3d orbitals in the basis set demonstrate that the usual parameters tend to overemphasize p,d, back-bonding. To rationalize available experimental data, 3d si orbitals need not to be considered explicitly-neither for the different dipole moments of methyl- and silylacetylenes nor for the general pe spectroscopic pattern of silicon compounds, i.e., high first ionization potential, reduced spin-orbit coupling, or band broadening.
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    Photoelektronen-Spektren von Methylidinphosphanen R-C≡P (Gasphasen-Reaktionen ; 31)
    (1982) Solouki, Bahman; Bock, Hans; Appel, Rolf; Westerhaus, Axel; Becker, Gerd; Uhl, Gudrun
    Die PE-spektroskopische Optimierung thermischer Zersetzungsreaktionen in der Gasphase wird auf die Chlor[(trimethylsilyl)methylen]phosphan-Derivate ((H3C)3Si)RC = PCl mit R = C6H5, Si(CH3)3 angewendet. In einer Kurzweg-Pyrolyse spaltet sich bei 1300 K quantitativ (H3C)3SiCl ab. Die gebildeten Methylidinphosphane (H3C)3Si-C-P und C6H5-C≡P lassen sich durch einen Vergleich ihrer PE-Spektren mit dem des stabilen tert-Butyl-Derivates (H3C)3-C≡P nachweisen und charakterisieren.