Photoelectron spectra of polysilanes. Conformational analyses of tetra-and penta-silane

Abstract

The p.e. spectra of polysilanes Si_nH_2n+2(n= 2,3,4,5) are presented. Whereas assignment is uncomplicated for n= 2 or 3, p.e. spectroscopic conformational analyses are necessary for tetra- and penta-silane. Their p.e. spectra can be simulated by CNDO eigenvalues (ε) if various rotamers are taken into account. For this procedure the relation Δε_i,j≈Δ(ionisation energy)_i,j must hold. Comparison of experimental and simulated spectra allows determination of the ratios of rotamers of Si₄H₁₀ and Si₅H₁₂ present under the p.e. spectroscopic conditions.