Theoretical X-ray photoelectron and emission spectra of Si- and S-containing polymers by density-functional theory calculations using model molecules

The X-ray photoelectron and emission spectra (XPS and XES) of Si- and S-con taining polymers [(-Si{-CH2-}(3))(n) (PCS), (-Si(CH3)(OH)-O-)(n) (PMHSO), ( -Si(C6H5)(OH)-O-)(n) (PTES), (-Si(C6H5)(OH)-O-Si(CH3)(OH)-O-)(n) (PPMHSO), (-C6H4-O-C6H4-SO2-)(n) (PES)] were simulated by the deMon density-functiona l theory (DFT) calculations using the model molecules. The theoretical vale nce photoelectron and C K alpha X-ray emission spectra showed good accordan ce with some experimental ones. The combined analysis of the valence XPS an d C and O K alpha XES enables us to divide the observed valence electronic distribution into the individual contributions for p sigma-, p pi- and non- bonding MOs of the polymers. (C) 2001 Elsevier Science B.V. All rights rese rved.