Aryl, bi-functionalised imidazo[4,5-f]-1,10-phenanthroline ligands and their luminescent rhenium(I) complexes

Autor: R. Owen Bonello, Mateusz B. Pitak, Graham J. Tizzard, Simon J. Coles, Ian A. Fallis, Simon J.A. Pope
Rok vydání: 2022
Předmět:
Zdroj: Polyhedron. 228:116179
ISSN: 0277-5387
DOI: 10.1016/j.poly.2022.116179
Popis: Five new imidazo[4,5-f]-1,10-phenanthroline based ligands (1–5) have been synthesised and characterised. The facile synthesis of 1–5 allows two regiochemical points of structural variety allowing highly conjugated and bulky aryl groups of varying functionalities, including azobenzene, trityl and terpyridine constituents, to be attached to the ligand core. 1–5 are fluorescent (λem = 410–415 nm), and react readily with [ReBr(CO)5] in toluene to give neutral coordination complexes of the form fac-[ReBr(CO)3(1–5)]. The series of complexes was characterised using a variety of spectroscopic and analytical techniques. Two examples of this series were characterised in the solid state using single crystal X-ray diffraction which confirmed the octahedral geometry and formulation. Photophysical studies showed that fac-[ReBr(CO)3(1–5)] are phosphorescent in solution under ambient conditions, revealing visible emission (558–585 nm) in aerated solution with corresponding lifetimes in the range 149–267 ns. These attributes are consistent with a triplet metal to ligand charge transfer (3MLCT) emitting state.
Databáze: OpenAIRE