Rethinking boron's role in intramolecular charge transfer: from an acceptor to a donor–acceptor regulator

Abstract

In-depth exploration of charge transfer contributes directly to the comprehension of the microscopic mechanisms underlying life processes while accelerating progress in the cutting-edge fields of organic electronics. At the molecular level, the boron atom with its unique empty p-orbital has been widely exploited to construct intramolecular charge transfer (ICT) molecules. This perspective seeks to thoroughly examine the types and emerging mechanisms of ICT in both tricoordinate and tetracoordinate organoboron-based ICT molecules (OBCTs), thereby clarifying boron's role in the ICT process. With respect to three-coordinated OBCTs, organoboron molecules with distinct CT pathways and distances are discussed in terms of their development history, CT mechanisms and structure–property relationships, which can provide guidance for designing highly sought-after molecules. For four-coordinated OBCTs, emerging CT mechanisms and the role of coordination in modulating CT properties are discussed, indicating substantial opportunities for the development of CT in these systems. In addition, the development of novel CT mechanisms or the integration of multiple CT processes holds promise for overcoming existing limitations in current OBCTs. Coupling the advancement of CT mechanisms with the discovery of innovative application scenarios is poised to propel the future progression of OBCTs.