Structural effects in the electron absorptio and luminescence spectra of decaborane(14) derivatives B10H12L2

Abstract

The electron absorption and luminescence spectra of some adducts B10H12L2 with L-alkylsubstituted pyridines are compared. In each subgroup with mono- and disubstituted pyridines, the largest hypsochromic shift of the long-wave edge of the charge transfer band (CTB) and the increased fluorescence yield correspond to the maximum basicity of L. Steric strains between the ortho methyl group of L and |B10H12| result in an insignificant bathochromic shift of the CTB and decrease the fluorescence yield. The optimal interactions |B10H12|→L, which are responsible for the absorption and emission properties of the adducts, should correspond to conformations where the planes of the heterocyclic system of L make an angle of 30° and are symmetric relative to the |B10H12| plane.