title: Luminescence of ruthenium halide complexes containing a hemilabile phosphine pyrenyl ether ligand.
abstract: A series of Ru(II) complexes, tcc-RuX2(POC4Pyr-P,O)2 (X = Cl (3), Br (4), I (5)), containing the hemilabile phosphine pyrenyl ether ligand 4-{2-(diphenylphosphino)phenoxy}butylpyrene (POC4Pyr (1)) are reported. The synthesis and spectroscopic properties of both the ligand, POC4pyr (1), and ligand oxide, P(=O)OC4pyr 2, and the solid-state structure of 1 are reported. Complexes 3-5 react rapidly with CO to give complexes ttt-RuX2(CO)2(POC4pyr-P)2 (X = Cl (6), Br (7), I (8)). No pyrene excimer emission is detected from 3-5; however, different intensities of excimer emission are observed for 6-8. The intensity of excimer emission decreases through the series, with 6 showing the most intense response. The emission is solely due to intramolecular pyrene excimers at low concentrations (< or =10(-4) M). Comparison of the UV-vis and steady-state fluorescence spectra shows overlap between the low energy d-d absorption of 7 and 8 with excimer emission (480 nm), suggesting nonradiative energy transfer may be occurring. Once excess CO is removed, complexes 6-8 isomerize to cis-dicarbonyl complexes cct-RuX2(CO)2(POC4Pyr-P)2 (X = Cl (9), Br (10), I (11)). The intensity of excimer emission from 9-11 increases with respect to the excimer emission observed for 6-8, with 9 showing a significant increase in excimer intensity.
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Matkovich
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Thorne
authors.forename: Michael O
authors.initials: MO
authors.lastname: Wolf
authors.forename: Tamara C S
authors.initials: TC
authors.lastname: Pace
authors.forename: Cornelia
authors.initials: C
authors.lastname: Bohne
authors.forename: Brian O
authors.initials: BO
authors.lastname: Patrick