Microsecond Excited-State Lifetimes in Bistridentate Ruthenium-Terpyridine Complexes

Brown, Douglas; Sanguantrakun, Nawaporn; Schulze, Benjamin; Schubert, Ulrich S.; Berlinguette, Curtis

Abstract:

A series of heteroleptic bis(tridentate) ruthenium(II) complexes, each bearing a substituted 2,2′:6′,2″-terpyridine (terpy) ligand, is characterized by room temperature microsecond excited-state lifetimes. This observation is a consequence of the strongly σ- donating and weakly π-accepting tridentate carbene ligand, 2′,6′-bis(1-mesityl-3-methyl-1,2,3-triazol-4-yl-5-idene)- pyridine (C∧N∧C), adjacent to the terpy maintaining a large separation between the ligand field and metal-toligand charge transfer (MLCT) states while also preserving a large 3MLCT energy. The observed lifetimes are the highest documented lifetimes for unimolecular ruthenium- (II) complexes and are four orders in magnitude higher than that associated with [Ru(terpy)2]2+.

Year:

2012

Type of Publication:

Article

Journal:

Journal of the American Chemical Society

Volume:

134

Pages:

12354 - 12375