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

The self‐assembly synthesis and structural characterization of the first representatives of diselenophosphinato octanuclear Cu I clusters inscribed in a twelve‐vertex selenium polyhedron are reported herein. An extremely facile (room temp., THF, 1 h) reaction between [Cu(MeCN) 4 ](PF 6 ) and ammonium diselenophosphinate, [NH 4 ][Se 2 P(CH 2 CH 2 Ph) 2 ] ( 1 ), in a 4:3 molar ratio resulted in the self‐assembly of copper(I) cluster [Cu 8 {Se 2 P(CH 2 CH 2 Ph) 2 } 6 ](PF 6 ) 2 ( 2 ) containing an empty Cu 8 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 ](PF 6 ) with diselenophosphinate 1 in the presence of [Cs 4 (P 2 Se 6 )(H 2 O) 4 ] as Se 2– source under the same conditions gave neutral selenide‐centered octanuclear copper cluster [Cu 8 (Se){Se 2 P(CH 2 CH 2 Ph) 2 } 6 ] ( 3 ). Three novel anion‐centered Cu 8 clusters of general formula [Cu 8 (X){Se 2 P(CH 2 CH 2 Ph) 2 } 6 ](PF 6 ) [X = H ( 4 ), Cl ( 5 ), or Br ( 6 )] were synthesized in high yields by self‐assembly reactions between Cu[(MeCN) 4 ]PF 6 and diselenophosphinate 1 in the presence of the corresponding anion sources (NaBH 4 for H – , Bu 4 NCl for Cl – , and [Bu 4 N]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 Cu 8 core capped by six diselenophosphinate ligands, whereas cluster 4 contains a tetracapped tetrahedral Cu 8 cage with an interstitial hydride anion. In all the clusters, each of the six diselenophosphinate ligands exhibits a tetrametallic tetraconnective (μ 2 ,μ 2 ) coordination pattern.