Dual photoemissions from the room temperature solutions of the tetranuclear copper(I) clusters Cu4I4(py-X)4(py-X = substituted pyridine)

Abstract

The time-resolved emission spectra of the tetranuclear clusters Cu₄I₄(py-X)₄(X = H, 3-Cl, 4-Ph, 4-PhCH₂, or 4-Bu^t) at 296 K in toluene each display separate, uncoupled emissions from two states, a short-lived (0.13–0.56 µs) metal-to-ligand charge transfer in the range 473–537 nm and a much more intense and longer lived (10–13 µs) metal cluster centred (MCC) emission in the range 678–698 nm; for X = 4-Ph the MCC emission exhibits an unusual, temperature dependent rise-time.