An organic-ligand-free thermochromic luminescent cuprous iodide trinuclear cluster: evidence for cluster centered emission and configuration distortion with temperature

An organic-ligand-free cuprous iodide trinuclear cluster with significant temperature-dependent structural distortion has been synthesized and characterized, which shows thermochromic luminescence originating from a single cluster-centered triplet due to the absence of an organic ligand. This compound also shows interesting reversible temperature dependent phase transition from chiral to centro-symmetric space groups.