Syntheses and structures of the heterometallic clusters [(Ph3PAu)3Re(CO)4], [(Ph3PAu)4Re(CO)4]+, [(Ph3PAu)6AuRe2(CO)8]+, and [(Ph3PAu)6Re(CO)3]+

The reaction of [HRe3(CO)12]2− with an excess of Ph3PAuCl in CH2Cl2 yields [(Ph3PAu)4Re(CO)4]+ as the main product, which crystallizes as [(Ph3PAu)4Re(CO)4]PF6 · CH2Cl2 (1 · CH2Cl2) after the addition of KPF6.The crystal structure determination reveals a trigonal bipyramidal Au4Re cluster with the Re atom in equatorial position.If [(Ph3PAu)4Re(CO)4]+ is reacted with PPh4Cl, a cation [Ph3PAu]+ is eliminated as Ph3PAuCl, and the neutral cluster [(Ph3PAu)3Re(CO)4] (2) is formed.It combines with excess [(Ph3PAu)4Re(CO)4]+ to afford the cluster cation, [(Ph3PAu)6AuRe2(CO)8]+. It crystallizes from CH2Cl2 as[(Ph3PAu)6AuRe2(CO)8]PF6 · 4CH2Cl2 (3 · 4CH2Cl2). In [(Ph3PAu)3Re(CO)4] the metal atoms are arranged in form of a lozenge while in [(Ph3PAu)6AuRe2(CO)8]+ two Au4Re trigonal bipyramids are connected by a common axial Au atom.The treatment of [(Ph3PAu)4Re(CO)4]+ with KOH and Ph3PAuCl in methanol yields the cluster cation [(Ph3PAu)6Re(CO)3]+, which crystallizes with PF6- from CH2Cl2 as [(Ph3PAu)6Re(CO)3]PF6 · CH2Cl2 (4 · CH2Cl2). The metal atoms in this cluster form a pentagonal bipyramid with the Re atom in the axial position.

The new heterometallic rhenium gold clusters [(Ph3PAu)3Re(CO)4], [(Ph3PAu)4Re(CO)4]+, [(Ph3PAu)6AuRe2(CO)8]+, and [(Ph3PAu)6Re(CO)3]+ have been synthesized and structurally characterized.[(Ph3PAu)4Re(CO)4]+ is obtained from [HRe3(CO)12]2− and Ph3PAuCl.It reacts with Cl− to yield the neutral cluster [(Ph3PAu)3Re(CO)4] and Ph3PAuCl.[(Ph3PAu)3Re(CO)4] and [(Ph3PAu)4Re(CO)4]+ condense to form the larger cluster [(Ph3PAu)6AuRe2(CO)8]+.The famous base reaction is used to obtain [(Ph3PAu)6Re(CO)3]+ from [(Ph3PAu)4Re(CO)4]+, Ph3PAu+ and OH−.Figure optionsDownload as PowerPoint slide