Heteroleptic Pyridyl‐Carbene Iron Complexes with Tuneable Electronic Properties

Abstract

Abstract New heteroleptic iron complexes mixing a terpyridine bearing a protonable pyridyl substituent (pytpy) and a pyridyl carbene ligand (carb) have been prepared and characterised by UV/Vis spectroscopy, cyclic voltammetry and TD‐DFT computations. The absorption spectrum of [Fe(carb)(pytpy)] 2+ showed a notable redshift compared with the homoleptic [Fe(carb) 2 ] 2+ complex. The MLCT transition occurred at even lower energy when the pendant pyridine was protonated, leading to a wide absorption domain in the 450–650 nm range. Calculations revealed the strong propensity of excited electrons to move from the metal to the pytpy ligand in the complex. This new family of complexes is a promising addition to the arsenal of iron‐based chromophores with tuneable electronic properties.