title: Simple Cu(I) complexes with unprecedented excited-state lifetimes.
abstract: This report describes new, readily accessible copper(I) complexes that can exhibit unusually long-lived, high quantum yield emissions in fluid solution. The complexes are of the form [Cu(NN)(POP)]+ where NN denotes 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) or 2,9-di-n-butyl-1,10-phenanthroline (dbp) and POP denotes bis[2-(diphenylphosphino)phenyl] ether. Modes of characterization include X-ray crystallography and cyclic voltammetry. The complexes each have a pseudotetrahedral coordination geometry and a Cu(II)/Cu(I) potential upward of +1.2 V vs Ag/AgCl. In room-temperature dichloromethane solution, charge-transfer excited states of the dmp and dbp derivatives exhibit respective emission quantum yields of 0.15 and 0.16 and corresponding excited-state lifetimes of 14.3 and 16.1 mus, respectively. Despite the fact that coordinating solvents usually quench charge-transfer emission from copper systems, the photoexcited dmp (dbp) complex retains a lifetime of 2.4 mus (5.4 mus) in methanol.
authors.affiliation: Department of Chemistry, Purdue University, 1393 Brown Building,West Lafayette, Indiana 47907-1393, USA.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Cuttell
authors.forename: Shan-Ming
authors.initials: SM
authors.lastname: Kuang
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Fanwick
authors.forename: David R
authors.initials: DR
authors.lastname: McMillin
authors.forename: Richard A
authors.initials: RA
authors.lastname: Walton