Electron‐Deficient Conjugated Materials via p–π* Conjugation with Boron: Extending Monomers to Oligomers, Macrocycles, and Polymers

Abstract

Among conjugated hybrid materials, tricoordinate boranes are attracting ever increasing attention because the empty p‐orbital on boron not only provides for significant Lewis acidity, but interactions with neighbouring pi‐electron systems produce unique optical and electronic properties. In this review, we systematically discuss the development of pi‐extended organoboranes from both theoretical and experimental perspectives. A key question is how the electronic structure of organoboranes changes upon extension from molecules to oligomers, macrocycles, and polymers. An analysis of the p‐pi* conjugation, and of mutual interactions between electron‐deficient boron centers across p ‐conjugated linkers, allows for important structure‐property relationships to be deduced. We also illustrate how the unique properties of these boron‐containing pi‐conjugated systems are exploited in the field of organic optical and optoelectronic device materials.