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

Two closely related Fe^II complexes 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 similar ³MLCT lifetime as the tris(bidentate) [Fe(C^C)₂(N^N)]²⁺ complexes with four mesoionic carbenes. [ABSTRACT FROM AUTHOR]