Facile Self‐Assembly Synthesis and Characterization of Diselenophosphinato Octanuclear CuI Clusters Inscribed in a Twelve‐Vertex Selenium Polyhedron

Abstract

AbstractThe self‐assembly synthesis and structural characterization of the first representatives of diselenophosphinato octanuclear CuI clusters inscribed in a twelve‐vertex selenium polyhedron are reported herein. An extremely facile (room temp., THF, 1 h) reaction between [Cu(MeCN)4](PF6) and ammonium diselenophosphinate, [NH4][Se2P(CH2CH2Ph)2] (1), in a 4:3 molar ratio resulted in the self‐assembly of copper(I) cluster [Cu8{Se2P(CH2CH2Ph)2}6](PF6)2 (2) containing an empty Cu8 cubic core. Meanwhile, when the reactants were allowed to react in the presence of appropriate anion sources, new anion‐centered octanuclear copper(I) clusters self‐assembled. Thus, the interaction of [Cu(MeCN)4](PF6) with diselenophosphinate 1 in the presence of [Cs4(P2Se6)(H2O)4] as Se2– source under the same conditions gave neutral selenide‐centered octanuclear copper cluster [Cu8(Se){Se2P(CH2CH2Ph)2}6] (3). Three novel anion‐centered Cu8 clusters of general formula [Cu8(X){Se2P(CH2CH2Ph)2}6](PF6) [X = H (4), Cl (5), or Br (6)] were synthesized in high yields by self‐assembly reactions between Cu[(MeCN)4]PF6 and diselenophosphinate 1 in the presence of the corresponding anion sources (NaBH4 for H–, Bu4NCl for Cl–, and [Bu4N]Br forBr–) under exceptionally mild conditions (room temp., THF, 4 h). X‐ray diffraction studies showed structures 3, 5, and 6 to consist of an anion‐centered cubic Cu8 core capped by six diselenophosphinate ligands, whereas cluster 4 contains a tetracapped tetrahedral Cu8 cage with an interstitial hydride anion. In all the clusters, each of the six diselenophosphinate ligands exhibits a tetrametallic tetraconnective (μ2,μ2) coordination pattern.