ANOMERIC EFFECT IN HEXAETHYLDISILATHIANE AND BIS(TRIETHYLSILYLALKYL) SULFIDES S[(CH2)NSIET3]2, N=0-3

The Kalpha and Kbeta fluorescence spectra of sulphur for hexaethyldisi lathiane and bis(triethylsilylalkyl) sulphides of general formula S[(C H2)nSiEt3]2, n = 0-3 have been investigated. The electron donor influe nce of the triethylsilyl group on the sulphur atom alternates, being m aximal for n = 0, 2 and minimal for n = 1, 3. The HOMO is strongly bon ding for n = 0, weakly anti-bonding for n = 2 and strongly anti-bondin g for n = 1, 3. The observed effects are explained by n(S)-sigma(SiC) , n(S)-sigma(CSi), n(S)-sigma(CC) and sigma(CC)-sigma(SiC) conjugatio ns over the whole molecule.