Preparation, Structure, and Properties of Tris(trimethylsilyl)silyl-substituted Anthracenes: Realization of Ideal Conformation for σ–π Conjugation Involving Eclipse of Si–Si σ-Bond with p-Orbital of Aromatic Ring

Abstract

Abstract Synthesis and X-ray diffraction analysis of 9- and 9,10-tris(trimethylsilyl)silyl (TTMSS)-substituted anthracenes were carried out to disclose that one of the Si–Si σ-bonds in the TTMSS-substituted anthracenes were perpendicular to the aromatic rings. The introduction of the TTMSS groups induced red shift of UV absorption and fluorescence emission maxima as compared with the parent and 9-pentamethyldisilanylated anthracenes. Theoretical calculation suggests LUMO levels of the TTMSS-substituted anthracenes are lowered by σ*–π* orbital interaction.