Synthesis and Photophysical Properties of Two Strongly Fluorescent Bis(diquinaldinatoalumino)-9-silafluorenes

Two novel highly fluorescent blue light emitting compounds were synthesized: 9,9-bis(diquinaldinatoalumino)-1,3-diphenyl-9-silafluorene (4) and 9,9-bis(diquinaldinatoalumino)-9-silafluorene (7). Combining silafluorene and quinaldinate aluminum moieties resulted in molecules with high quantum yield efficiency both in solution (31–34%) and in the solid state (79–92%). 4 showed intense electroluminescence, 4090 cd/m2 at 15 V, and the mechanochromism of 7 was revealed.