Nanosized starlike molecules. Synthesis and optical properties of tris- and tetrakis[oligo(disilanylenebithienylene)dimethylsilyl]benzene

The syntheses of two types of starlike molecules with the arms that extend to three and four directions have been reported. The molecules with the arms consisting of a regular alternating arrangement of a silicon–silicon bond and bithienylene unit that extend to three directions were synthesized by the reactions of 1,3,5-tris(chlorodimethylsilyl)benzene, which was chosen as a core, with the lithio[oligo(disilanylenebithienylene)] derivatives. The starlike molecules with extended arms to four directions were prepared by the reaction of 1,2,4,5-tetrakis(fluorodimethylsilyl)benzene used as a core, with lithio[oligo(disilanylenebithienylene)]s. UV–Vis absorption and fluorescence properties of these starlike molecules have been investigated in a dioxane solution. The present molecules showed absorption maxima in a range of 321–337 nm, and revealed higher fluorescence quantum yields than that of the corresponding linear polymer, poly[(tetraethyldisilanylene)bithiophene].