Isolation, optical properties and core structure of a water-soluble, phosphine-stabilized [Au_9]~(3+) cluster

摘要

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_2O in ethanol. Characterization by optical extinction spectroscopy, single-crystal 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_2O (0 ≤ x ≤ 3, n ≈ 16) with the cluster core in crown conformation. ~(31)P{ ~1H} 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.