Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited.

ABSTRACT: Iron N-heterocyclic carbene (FeNHC) complexes with long-lived charge transfer states are emerging as a promising class of photoactive materials. We have synthesized [Fe^II(ImP)₂] (ImP = bis(2,6-bis(3-methylimidazol-2-ylidene-1-yl)phenylene)) that combines carbene ligands with cyclometalation for additionally improved ligand field strength. The 9 ps lifetime of its ³MLCT (metal-to-ligand charge transfer) state however reveals no benefit from cyclometalation compared to Fe(ii) complexes with NHC/pyridine or pure NHC ligand sets. In acetonitrile solution, the Fe(ii) complex forms a photoproduct that features emission characteristics (450 nm, 5.1 ns) that were previously attributed to a higher (²MLCT) state of its Fe(iii) analogue [Fe^III(Im

SUBMITTER: Johnson CE 

PROVIDER: S-EPMC10530338 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature