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

Article abstract of DOI:10.1016/j.ica.2005.02.022

The reaction of [HRe₃(CO)₁₂]^2- with an excess of Ph₃PAuCl in CH₂Cl₂ yields [(Ph ₃PAu)₄Re(CO)₄]⁺ as the main product, which crystallizes as [(Ph₃PAu)₄Re(CO) ₄]PF₆·CH₂Cl₂ (1·CH₂Cl₂) after the addition of KPF ₆.The crystal structure determination reveals a trigonal bipyramidal Au₄Re cluster with the Re atom in equatorial position. If [(Ph ₃PAu)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 [(Ph ₃PAu)₄Re(CO)₄]⁺ to afford the cluster cation, [(Ph₃PAu)₆AuRe₂(CO) ₈]⁺. It crystallizes from CH₂Cl₂ as[(Ph₃PAu)₆AuRe₂(CO)₈]PF ₆·4CH₂Cl₂ (3·4CH ₂Cl₂). 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 [(Ph ₃PAu)₆Re(CO)₃]PF₆·CH ₂Cl₂ (4·CH₂Cl₂). The metal atoms in this cluster form a pentagonal bipyramid with the Re atom in the axial position.