INNER-SHELL SPECTROSCOPY OF COMPOUNDS CONTAINING SI-SI BONDS - IS THERE A LOCALIZED, LOW-ENERGY SI-SI RESONANCE

Oscillator strengths for the Si 2p, Si 2s, and C Is excitation of tetr amethylsilane, hexamethyldisilane, tetrakis(trimethylsilyl)silane, and dodecamethylcyclohexasilane have been derived from electron energy lo ss spectra recorded in the dipole-regime. These results are compared t o the Si 1s and Si 2p photoabsorption spectra of tetramethylsilane, he xamethyldisilane, tris(trimethylsilyl) silane, and tetrakis( trimethyl silyl) silane, recorded using synchrotron radiation. The spectra suppo rt the existence of a localised, low-lying state of large Si-Si charac ter in species which contain Si-Si bonds.