Nanosized, Starlike Silicon Compounds. Synthesis and Optical Properties of Tris[(<i>tert</i>-butyldimethylsilyl)oligothienylenedimethylsilyl]methylsilanes

Abstract

Starlike molecules with arms consisting of a tert-butyldimethylsilyloligothienylenedimethylsilyl unit, MeSi[SiMe2(T)nSiMe2(t-Bu)]3 (7−11; n = 2−6, T = thienylene) were prepared by the reactions of tris(chlorodimethylsilyl)methylsilane, which was chosen as a core, with the tert-butyldimethylsilyl-substituted lithiooligothienylenes used for construction of the arms. UV−visible absorption and fluorescence properties of 7−11 have been studied in a dioxane solution. The molecules 7−11 showed high fluorescence quantum yields with respect to the corresponding oligothiophenes. Compounds 7 and 8 revealed longer lifetimes than those of bi- and terthiophene. The results of X-ray crystallographic analysis of the bromo derivative 12 are described. The density functional theoretical calculations were also carried out to compare the geometrical structures and the excitation energies with the available experimental data.