Synthesis and Optical Evaluation of Fused Azo-bisboronComplexes Having Expanded Conjugated Systems through AzoGroups

摘要

In general,the extension of π-conjugation through repeating units via vinylene groups,such as poly(p-phenylene vinylene),contributes to enhancing emission performances.Onthe other hand,by replacing with azo groups involving nitrogen-nitrogen double bonds,emission is no longer observed due to emission annihilation through photoiosmerization.Therefore,only absorption and photoswitching behaviors have been focused.In ourprevious research,based on the tridentate ligand,2,2'-dihydroxyazobenzene,we constructedthe compounds having ring-fused structures with the boron-nitirogen coordination.Accordingly,photoluminescence was obtained because of the suppression of thephotoisomerization.1 In this research,we synthesized azo-bisboron complexes havingextended π-conjugated systems via two azo groups.From detailed evaluation with thesecompounds,effect on optical properties was clarified.