Dirhodium C-H Functionalization of Hole-Transport Materials

Hole-transport materials (HTMs) based on triarylamine derivatives play important roles in organic electronics applications including organic light-emitting diodes and perovskite solar cells. For some applications, triarylamine derivatives bearing appropriate binding groups have been used to functionalize surfaces, while others have been incorporated as side chains into polymers to manipulate the processibility of HTMs for device applications. However, only a few approaches have been used to incorporate a single surface-binding group or polymerizable group into triarylamine materials. Here, we report that Rh-carbenoid chemistry can be used to insert carboxylic esters and norbornene functional groups into sp2 C-H bonds of a simple triarylamine and a 4,4 '-bis(diarylamino)biphenyl, respectively. The norbenene-functionalized monomer was polymerized by ring-opening metathesis; the electrochemical, optical, and charge-transport properties of these materials were similar to those of related materials synthesized by conventional means. This method potentially offers straightforward access to a diverse range of HTMs with different functional groups.

Automated summary

Hole-transport materials (HTMs) based on triarylamine derivatives are important in organic electronic applications. This study presents a method to incorporate carboxylic esters and norbornene functional groups into sp2 C-H bonds of triarylamine materials using Rh-carbenoid chemistry. The resulting materials exhibit similar properties to those synthesized by conventional means and offer a straightforward approach to diverse HTMs with different functional groups.