Distinct photodynamics of κ-N and κ-C pseudoisomeric iron(ii) complexes

Abstract

Two closely related FeIIcomplexes with 2,6-bis(1-ethyl-1H-1,2,3-triazol-4yl)pyridine and 2,6-bis(1,2,3-triazol-5-ylidene)pyridine ligands are presented to gain new insights into the photophysics of bis(tridentate) iron(ii) complexes. The [Fe(N^N^N)2]2+pseudoisomer sensitizes singlet oxygen through a MC state with nanosecond lifetime after MLCT excitation, while the bis(tridentate) [Fe(C^N^C)2]2+pseudoisomer possesses a similar3MLCT lifetime as the tris(bidentate) [Fe(C^C)2(N^N)]2+complexes with four mesoionic carbenes.