Synthesis, X‐ray Structures, and Photoluminescence of the Octahedral Cu4I4 Cluster with Bulky Bidentate Bis(phosphanyl)amine Ligand

Abstract

The reaction of C10H7‐1‐N(PPh2)2 (1) with two equivalents of CuI in acetonitrile resulted in the formation of octahedron Cu4I4[1]2 complex (2). The crystal structure of 2 showed it adopted a rare octahedral arrangement. The rectangular Cu4 plane is μ4‐capped by two of the iodides and is placed in axial positions above and below the Cu4‐plane form an octahedron, whereas the other two iodides are bonded to two copper atoms in a μ2‐fashion. The luminescence of complex 2 arises from a triplet halide‐to‐ligand charge transfer (3XLCT) excited state and 3CC (Cu4I4 cluster‐centered) excited state are not involved in the luminescence by the rigid bidentate ligand 1 in spite of the short CuI–CuI bond length. Complex 2 was identified and characterized by multinuclear NMR (1H, 13C, 31P NMR) and IR spectroscopy. Crystal structure determinations of 1 and 2 were carried out.