A new record excited state 3MLCT lifetime for metalorganic iron(ii) complexes†
Abstract
Herein we report the synthesis and time-resolved spectroscopic characterization of a homoleptic Fe(II) complex exhibiting a record 3MLCT lifetime of 26 ps promoted by benzimidazolylidene-based ligands. Time dependent density functional molecular modeling of the triplet excited state manifold clearly reveals that, at equilibrium geometries, the lowest 3MC state lies higher in energy than the lowest 3MLCT one. This unprecedented energetic reversal in a series of iron complexes, with the stabilization of the charge-transfer state, opens up new perspectives towards iron-made excitonic and photonic devices, hampering the deactivation of the excitation via metal centered channels.