Cooperation of σ-π and σ*-π* Conjugation in the UV/Vis and Fluorescence Spectra of 9,10-Disilylanthracene

In 1996, we reported that silyl groups of 9,10-disilylanthracenes significantly affect the UV/Vis and fluorescence spectra. Although the results indicate that the silyl groups have strong electronic effects on anthracene, the details of the mechanisms responsible for this have not yet been clarified. This article describes the analysis of the UV/Vis and fluorescence spectra of 9,10-bis(diisopropylsilyl)anthracene by theoretical calculations. This study reveals that pi conjugation of anthracene is extended by cooperation of sigma-pi and sigma*-pi* conjugation between the silyl groups and anthracene. This effect increases the transition moment of the pi-pi* transition of anthracene. As a result, the molecular extinction coefficient of the L-1(a) band and the fluorescence quantum yield are increased.

Automated summary

This study analyzed the UV/Vis and fluorescence spectra of 9,10-bis(diisopropylsilyl)anthracene through theoretical calculations. It revealed that the cooperation between the silyl groups and anthracene extended the pi conjugation of anthracene, resulting in increased molecular extinction coefficient and fluorescence quantum yield.