Synthesis, structural studies, and photophysical properties of heteroleptic inverse-coordination clusters

Abstract

Two series of hyper-coordinated halide-centered M₁₂ cuboctahedral clusters, [M₁₂(μ₁₂-X){S₂P(OⁿPr)₂}₆{CCPh}₄](PF₆), 1a–c and 2a–c (where M = Cu, 1; Ag, 2; X = Cl, a; Br, b; I, c), were synthesized and fully characterized by ESI-MS, multi-NMR spectroscopy, IR and UV-Vis spectroscopy, photoluminescence analysis, and single-crystal X-ray crystallography. Structures 1c, 2b, and 2c show a twelve-coordinated halide encapsulated in the M₁₂ cage, which is stabilized by six dithiophosphate and four alkynyl ligands. Compound 2b is the first Ag(I) cluster containing a twelve-coordinated bromide. The structural features of all six clusters are highly similar, providing a comparison basis of the inverse coordination for halides. Besides, the detailed structural analysis illustrates how the inverse coordination of a halide has influenced the size of the cuboctahedral M₁₂ framework.