Synthesis, X‐ray Structures, and Photoluminescence of the Octahedral Cu 4 I 4 Cluster with Bulky Bidentate Bis(phosphanyl)amine Ligand

The reaction of C 10 H 7 ‐1‐N(PPh 2 ) 2 ( 1 ) with two equivalents of CuI in acetonitrile resulted in the formation of octahedron Cu 4 I 4 [ 1 ] 2 complex ( 2 ). The crystal structure of 2 showed it adopted a rare octahedral arrangement. The rectangular Cu 4 plane is μ 4 ‐capped by two of the iodides and is placed in axial positions above and below the Cu 4 ‐plane form an octahedron, whereas the other two iodides are bonded to two copper atoms in a μ 2 ‐fashion. The luminescence of complex 2 arises from a triplet halide‐to‐ligand charge transfer ( 3 XLCT) excited state and 3 CC (Cu 4 I 4 cluster‐centered) excited state are not involved in the luminescence by the rigid bidentate ligand 1 in spite of the short Cu I –Cu I bond length. Complex 2 was identified and characterized by multinuclear NMR ( 1 H, 13 C, 31 P NMR) and IR spectroscopy. Crystal structure determinations of 1 and 2 were carried out.