title: Ultrafast ligand exchange: detection of a pentacoordinate Ru(II) intermediate and product formation.
abstract: The ultrafast kinetics of ligand exchange of cis-[Ru(bpy)(2)(CH(3)CN)(2)](2+) were measured in H(2)O and CH(3)CN. The formation of the (3)MLCT excited-state and a five-coordinate intermediate are observed in both solvents within 2 ps after excitation (310 nm, fwhm approximately 300 fs). The (3)MLCT excited-state undergoes vibrational cooling (5-6 ps), then decays to regenerate the ground-state with a lifetime of approximately 50 ps. In CH(3)CN, ligand recombination takes place in 28 ps, while the formation of cis-[Ru(bpy)(2)(CH(3)CN)(H(2)O)](2+) in H(2)O takes place with tau = 77 ps.
authors.affiliation: Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.forename: David B
authors.initials: DB
authors.lastname: Turner
authors.forename: Tanya N
authors.initials: TN
authors.lastname: Singh
authors.forename: Alfredo M
authors.initials: AM
authors.lastname: Angeles-Boza
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Chouai
authors.forename: Kim R
authors.initials: KR
authors.lastname: Dunbar
authors.forename: Claudia
authors.initials: C
authors.lastname: Turro