Tailored Functional Monolayers Made from Mesoionic Carbenes

Significant progress has been made over the last decades in surface functionalization of coinage metals using thiols and more recently N-heterocyclic carbenes. As shown in this work, mesoionic carbenes (MICs) provide straightforward access to a novel class of surface ligands and thus materials. Importantly, MICs are easily accessed from triazolium salts (TS) onto which functional groups may be attached with little synthetic effort. Here, we present a library of TS that were further converted into MICs, in situ, and grafted to gold surfaces. The modified surfaces were thoroughly characterized by advanced spectroscopic methods and electrochemistry for MICs bearing electroactive moieties. We also prepared mixed MIC/thiol self-assembled monolayers, which opens the route to multifunctional surfaces.