Heteroaryldisilenes: heteroaryl groups serve as electron acceptors for Si[double bond, length as m-dash]Si double bonds in intramolecular charge transfer transitions.

Abstract

Although many stable disilenes (silicon-silicon doubly-bonded compounds) containing organic π-electron systems have been reported, stable disilenes with heteroaromatic groups remain rare. Herein, we report the synthesis of monodisilenyl-substituted thiophene 1, anthracene 4, acridine 5, and mesitylene 7 and bis(disilenyl)-substituted thiophene 2, 2,2'-bithiophene 3, and anthracene 6via reactions of dialkylmesityldisilenide 8 with the corresponding haloarenes. Disilenes 1-7 show absorption bands with contributions of intramolecular charge transfer (ICT) transitions from π(disilene) to π*(aryl). In the ICT transitions, (bi)thienyl groups as well as anthryl and acrydinyl groups serve as electron acceptors for the Si[double bond, length as m-dash]Si double bonds.