Novel silver diselenophosphate clusters: structures of Ag10(µ10-Se)[Se2P(OEt)2]8 and {Ag[Se2P(OPri)2]}6Metal dialkyl diselenophosphates. Part 5. For preceding paper see ref. 1.

Abstract

Two types of clusters, [Ag(Se2P(OR)2)]n (R = Et, n = ∞, 1a; R = Pri, n = 6, 1b) and Ag10(μ10-Se)[Se2P(OR)2]8 (2a, 2b) were obtained from the reaction of stoichiometric amounts of Ag(CH3CN)4PF6 and NH4Se2P(OR)2 in (C2H5)2O at −20 °C. These new silver(I) clusters containing diselenophosphate (dsep) ligands were characterized by elemental analysis, NMR spectroscopy, fast-atom bombardment mass spectrometry (FAB-MS) for 2, and, in the case of 1b, and 2a, by X-ray crystallography. The structure of 1b reveals a hexameric aggregate {Ag[Se2P(OPri)2]}6 where six silver atoms are located at the corners of a pseudohexagonal prism alternating with selenium atoms in two Ag3Se3 rings interconnected vertically by the P–Se bridges of the dsep ligands but not by additional Ag–Se bonding. The dsep ligands are organized in a paddle-wheel fashion about an Ag6Se6 pseudohexagonal prismatic core. The decasilver clusters 2 contain an encapsulated selenium atom in a distorted, cis-bicapped trapezoidal-prismatic geometry and are surrounded by eight dsep ligands having three different types of coordination pattern. Furthermore, the hypercoordinated selenide ion, Se2−, in 2 was unequivocally identified by the solution 77Se{1H} NMR spectrum with a chemical shift centered at −1396 ppm.