Synthesis, structure, photophysics, time-resolved emission spectroscopy and electrochemistry of luminescent copper(I) acetylide complexes
Abstract
A series of soluble trinuclear copper(I) complexes containing mono- and bi-capped µ3-η1-acetylides [Cu3(dppm)3(µ3-η1-CCR)]2+ and [Cu3(dppm)3(µ3-η1-C
CR)2]+(dppm = Ph2PCH2PPh2, R = Ph or But) have been synthesized and shown to exhibit long-lived dual luminescent behaviour. Their photophysics and electrochemistry and those of a mixed halide–acetylide capped trinuclear copper(I) complex [Cu3(dppm)3(µ3-η1-C
CBut)(µ3-Cl)]+ have been investigated. The origin of the low-energy emission (λem 525–700 nm) is ascribed to states of ds/l.m.c.t. admixture with large l.m.c.t. (ligand to metal charge transfer) character. The crystal structure of [Cu3(dppm)3(µ3-η1-C
CBu t)][PF6]2 has been determined. The complex consists of an isosceles triangular array of copper atoms with Cu–Cu distances of 2.910(1), 2.941(2) and 3.175(1)Å.