A study of the electronic structure of phenylsilanes by X-ray emission spectroscopy and quantum chemical calculation methods

The electronic structure of a series of phenylsilanes Ph_4?n SiH _n (n = 0?C3) is studied by X-ray emission spectroscopy and quantum chemical calculations by the density functional theory method. Based on the calculations theoretical X-ray emission SiK??₁ spectra of phenylsilanes Ph_4?n SiH _n (n = 0?C4) are constructed and their energy structure and shape turn out to be well consistent with experiment. The distribution of the electron density of states with different symmetry of Si, C, H atoms are also constructed. An analysis of the obtained X-ray fluorescent SiK??₁ spectra and the distribution of the electron density of states in Ph₄Si and Ph₃SiH compounds shows that their energy structure is mainly determined by a system of the energy levels of phenyl ligands weakly perturbed by interactions with valence AOs of silicon. In the energy structure of MOs of the PhSiH₃ compound, energy orbitals related to t ₂ and a ₁ levels of tetrahedral SiH₄ are mainly presented.     

Thermal conversions of dodecacarbonyltriiron on the surface of titanium and molybdenum disulfides

A study has been made of the influence of the sulfide substrate on the rate and direction of thermal decomposition, in an argon atmosphere, of Fe₃(CO)₁₂ deposited on the surface of crystalline MoS₂, TiS₂, and Co_0.5TiS₂ in amounts K=0.5–10 monolayers. It has been shown that the decomposition rate increases in the series MoS₂0.5TiS₂2 and increases with decreasing K. The relationship between the electronic structure of the sulfide and the decomposition of Fe₃(CO)₁₂ has been examined. On the basis of it has been established that the Fe atoms in the surface compounds that are formed by thermolysis of Fe₃(CO)₁₂ are coordinated with sulfur atoms S-M-S and are in a +2 degree of oxidation.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 44–47, January, 1992.