Synthesis of a tri(gold)boride complex (Cy3P)B[AuP(o-Tol) 3]3

Abstract

A tri(gold)boride of the formula B[AuP(o-Tol)3]3 (2) is generated in the reaction of the silylated phosphine borane Cy 3PBH2SiMe3 with the tri(gold)oxonium tetrafluoroborate [(o-Tol)3PAu]3O+ BF 4- and isolated as its stable 1: 1 complex with tricyclohexylphosphine: Cy3PB[AuP(o-Tol)3]3. The composition of the product has been confirmed by elemental analyses and mass spectrometry. Solution NMR data of 2 indicate a molecular structure with C 3v symmetry which has been confirmed by MP2 calculations for the model system H3PB(AuPH3)3. The compound is a rare case of a trimetallated boride which is isolobal with the simple phosphineborane Cy3PBH3. With reagents bearing less bulky substituents (R3 = iPr3, MePh2, Ph3), the reactions proceed to salts with the tetra-aurated cations [Cy3PB(AuPR3)4]+. © 2013 Verlag der Zeitschrift für Naturforschung, Tübingen.