A Heptanuclear Copper Iodide Nanocluster

Nanoscale molecular clusters are attractive for the design of materials exhibiting original functions and properties. In particular, copper iodide clusters of high nuclearity are well-known for their stimuli-responsive luminescence properties. The synthesis and characterization of an unprecedented copper(I) iodide molecular cluster based on an original heptanuclear inorganic core are reported. This nanometer-size cluster is formulated as [Cu₇I₇(P(C₆H₄CF₃)₃)₆(CH₃CN)] and its novel structure has been characterized by X-ray diffraction and multinuclear solid-state ⁶³Cu, ³¹P, ¹³C, ¹⁹F, and ¹H NMR spectroscopy. The photoluminescence properties of this cluster have been studied at variable temperature. Density functional theory calculations have been performed on this large molecular structure and allow one to rationalize the observed luminescence properties. This study highlights the crucial role of cuprophilic interactions in molecular copper iodide clusters for exhibiting photoactive properties.