Selective charge transfer in donor/acceptor systems bridged by Tröger base derivatives

• Tröger base motif is tested as a bridge connecting either hole or electron transfer.
• It is, although aliphatic (σ bridge), an excellent hole transporter.
• However and interestingly, it is very bad in coupling electron transport.
• This selective behavior could be exploited for designing new molecular devices.
• A calculation protocol is proposed for accurate predictions on the redox processes.

Recently, unusual charge transfer properties of two triarylamines bridged through an aliphatic bridge (Tröger base) have been reported. The donor/acceptor couple was shown to have an important electronic coupling between its centers for the hole transfer, although in the absence of a π linker. In contrast, we here show, by combining first principles calculations with experimental studies, that the bridge has a practically null role in coupling the electron transfer. This sharp contrast might present an interesting potential in the design of molecular devices.

A Tröger base bridge effectively couples the redox centers for hole transfer but not for electron transfer.Figure optionsDownload as PowerPoint slide