Syntheses and structures of the heterometallic clusters [(Ph 3PAu) 3Re(CO) 4], [(Ph 3PAu) 4Re(CO) 4] +, [(Ph 3PAu) 6AuRe 2(CO) 8] +, and [(Ph 3PAu) 6Re(CO) 3] +

Abstract

The reaction of [HRe 3(CO) 12] 2− with an excess of Ph 3PAuCl in CH 2Cl 2 yields [(Ph 3PAu) 4Re(CO) 4] + as the main product, which crystallizes as [(Ph 3PAu) 4Re(CO) 4]PF 6 · CH 2Cl 2 ( 1 · CH 2Cl 2) after the addition of KPF 6.The crystal structure determination reveals a trigonal bipyramidal Au 4Re cluster with the Re atom in equatorial position. If [(Ph 3PAu) 4Re(CO) 4] + is reacted with PPh 4Cl, a cation [Ph 3PAu] + is eliminated as Ph 3PAuCl, and the neutral cluster [(Ph 3PAu) 3Re(CO) 4] ( 2) is formed.It combines with excess [(Ph 3PAu) 4Re(CO) 4] + to afford the cluster cation, [(Ph 3PAu) 6AuRe 2(CO) 8] +. It crystallizes from CH 2Cl 2 as[(Ph 3PAu) 6AuRe 2(CO) 8]PF 6 · 4CH 2Cl 2 ( 3 · 4CH 2Cl 2). In [(Ph 3PAu) 3Re(CO) 4] the metal atoms are arranged in form of a lozenge while in [(Ph 3PAu) 6AuRe 2(CO) 8] + two Au 4Re trigonal bipyramids are connected by a common axial Au atom. The treatment of [(Ph 3PAu) 4Re(CO) 4] + with KOH and Ph 3PAuCl in methanol yields the cluster cation [(Ph 3PAu) 6Re(CO) 3] +, which crystallizes with PF 6 - from CH 2Cl 2 as [(Ph 3PAu) 6Re(CO) 3]PF 6 · CH 2Cl 2 ( 4 · CH 2Cl 2). The metal atoms in this cluster form a pentagonal bipyramid with the Re atom in the axial position.