Isolation, Optical Properties and Core Structure of a Water-soluble, Phosphine-stabilized [Au₉]³⁺ Cluster

Abstract

Abstract A water-soluble, crystalline Au 9 cluster compound stabilized with sodium (m-sulfonatophenyl) diphenylphosphine (TPPMSNa) was obtained during the NaBH 4 reduction of [Au(TPPMSNa)Cl] H 2 O in ethanol. Characterization by optical extinction spectroscopy, singlecrystal X-ray diffraction in combination with energy dispersive X-ray diffraction led to the preliminary formula Na (8-x) [Au 9 (TPPMS)8]Cl(3-x) nH 2 O (0 ≤ x ≤ 3, n ≈ 16) with the cluster core in crown conformation. 31 P{ 1 H} nuclear magnetic resonance spectroscopy revealed one singlet at 57:3 ppm. This is the first example where gold clusters stabilized by TPPMSNa formed crystals which where suitable for core structure determination