Luminescent molecular copper(I) alkynyl open cubes: Synthesis, structural characterization, electronic structure, photophysics, and photochemistry

Abstract

A novel class of tetranuclear copper(I) alkynyl complexes with an "open-cube" structure was synthesized. The crystal structure of [Cu4{P(p-MeC6H4)3} 4(μ3-η1,η1, η2-C ≡ C-p-MeO-C6H4) 3]PF6 was determined. These complexes were found to display dual emission behavior. Through systematic comparison studies on the electronic absorption and photoluminescence properties of a series of [Cu 4(PR3)4(μ3-η1, η1,η2-C ≡ CR′)3] + complexes, together with density functional theory (DFT) calculations at the PBE1PBE level on the model complex [Cu4(PH 3)4-(μ3-η1,η1, η2-C ≡ C-p-MeOC6H4)3] +, the nature of their emission origins was probed. Their photochemical properties were also investigated by oxidative quenching experiments and transient absorption spectroscopy. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.