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.