Synthesis and properties of blue light-emitting, silicon-containing, regio- and stereoregular conjugated polymers

This article concerns the hydrosilylation polyaddition of 1,4-bis(dimethylsilyl)benzene (1) with 4,4′-diethynylbiphenyl, 2,7-diethynylfluorene (2b), and 2,6-diethynylnaphthalene with RhI(PPh ₃)₃ catalyst. Trans-rich polymers with weight-average molecular weights (M_w's) ranging from 19,000 to 25,000 were obtained by polyaddition in o-Cl₂C₆H₄ at 150-180°C, whereas cis-rich polymers with M_w's from 4300 to 34,000 were obtained in toluene at 0°C-r.t. These polymers emitted blue light in 4-81% quantum yields. The cis polymers isomerized into trans polymers upon UV irradiation, whereas the trans polymers did not. The device having a layer of polymer trans-Sb obtained from 1 and 2b demonstrated electroluminescence without any dopant.