Synthesis of Siloles Condensed with Benzothiophene and Indole Rings

Compounds having a silole ring condensed with benzothiophene and N-methylindole units (BBTS and BMIS) were prepared. The electronic states of BBTS and BMIS were examined with respect to their UV and emission spectra and CV measurements, in comparison with those of bibenzothiophene and bi-N-methylindole, indicating that the existence of the silole ring in BBTS and BMIS affects the electronic states to decrease the HOMO−LUMO energy gaps. The results of MO calculations on model compounds agree well with the experimental observations.