X-Ray spectral and theoretical investigations of the electronic structure of phenylcyclosilanes (SiPh$_2$)$_n$ ($n$ = 4–6)

The X-ray emission SiK$\alpha_{1,2}$ and SiK$_{\beta_1}$ spectra of a series of phenylcyclosilanes (SiPh$_2$)$_n$ ($n$ = 4–6) have been obtained. Using the results of quantum-chemical calculations in the density functional theory approximation, the fine structure of SiK$_{\beta_1}$ spectra has been interpreted. Distributions of densities of electron states of silicon atoms over the valence band have been constructed and the types of chemical bonds providing the Si–Si and Si–Ph interactions have been established. Based on the theory of natural bond orbitals, the chemical bonding in the studied series of phenylcyclosilanes has been analyzed.