Nanosized starlike molecules. Synthesis and optical properties of 2,4,6-tris(disilanylenebithienylene)-1,3,5-triazine derivatives

Starlike molecules (5) and (7) that have a triazine unit as a core and arms consisting of an alterative arrangement of an Si–Si bond and bithienylene unit were prepared by the Pd-catalyzed reactions of 2,4,6-tris[5-(1,3-dioxa-4,4,5,5-tetramethyl-2-borolanyl)-2-thienyl]triazine with 5-bromothienylpentamethyldisilane and with 1-(5-bromothienyl)-2-bithienyltetramethyldisilane, respectively. In the UV–vis absorption and fluorescence spectra, 5 and 7 showed absorption maxima in a range of 398–399 nm, and revealed higher fluorescence quantum yields than that of 2,4,6-tris(bithienyl)triazine.