1-Carbazolyl Spirobifluorene: Synthesis, Structural, Electrochemical, and Photophysical Properties

Abstract

The present work reports one of the rare examples of a new emerging family of spirobifluorene derivatives, namely, 1-substituted spirobifluorenes. We report the synthesis and the structural, electrochemical, and photophysical properties of 9-(9,9′-spirobi[fluorene]-1-yl)-9H-carbazole 1-Cbz-SBF, constructed from the connection of the widely known electron-rich carbazole fragment at the C1 position of spirobifluorene. We show with 1-Cbz-SBF that the substitution at C1 induces two important characteristics which drive the electronic properties. First, there is a complete π-conjugation breaking between the pending substituent, herein, carbazole, and the substituted fluorene. Second, there is a through-space interaction between the carbazole and its cofacial fluorene. Thanks to a structure–property relationship approach with its constituting building blocks 9,9′-spirobifluorene SBF and carbazole Cbz, we show how some electronic properties are driven by the carbazole unit such as the highest occupied molecular ...