Recent experimental and theoretical aspects of the conformational dependence of UV absorption of short chain peralkylated oligosilanes

Recent experimental and theoretical aspects of the conformation dependence of UV absorption of short chain peralkylated oligosilanes are surveyed. In the current interpretation of the conformational effect on tetrasilane electronic transitions it is not the excitation energy but the intensity of the lowest valence transitions that changes significantly as the SiSiSiSi dihedral angle varies. The latest synthetic advances have enabled us to constrain the conformation of silicon backbone in oligosilanes to some extent to provide strong experimental evidence for the theoretical proposals. A similar conformational effect has been found for a series of hexasilane conformers. (C) 2003 Elsevier Science B.V. All rights reserved.