Heteronuclear Hexaplatinum Cluster Complexes: Structure as a Function of Electron Count.

The 84-electron hexaplatinum cluster complex [Pt(6)(&mgr;-CO)(6)(&mgr;-dppm)(3)], 1, dppm = Ph(2)PCH(2)PPh(2), reacts in a 1:2 molar ratio with either 0-electron metalloligands LM(+) (L = Ph(3)P, M = Cu, Ag, Au; L = iPr(3)P, M = Au) or InX(3) (X = Cl, Br) or 2-electron metalloligands Tl(+) and Hg to give the corresponding 84-electron clusters Pt(6)(&mgr;(3)-ML)(2)(&mgr;-CO)(6)(&mgr;-dppm)(3) or [Pt(6)(&mgr;(3)-InX(3))(2)(&mgr;-CO)(6)(&mgr;-dppm)(3)] or 88-electron clusters Pt(6)(&mgr;(3)-Tl)(2)(&mgr;-CO)(6)(&mgr;-dppm)(3) and [Pt(6)(&mgr;(3)-Hg)(2)(&mgr;-CO)(6)(&mgr;-dppm)(3)], respectively. The mercury cluster is oxidized by CH(2)I(2) to give the known 86-electron cluster [Pt(6)(&mgr;(3)-HgI)(2)(&mgr;-CO)(6)(&mgr;-dppm)(3)]. Reaction of 1 with Ir(CO)(4) occurs in a 1:1 ratio only to give the 98-electron anionic cluster Pt(6){&mgr;(3)-Ir(CO)(2)}(&mgr;-CO)(6)(&mgr;-dppm)(3), which reacts with Ph(3)PAu to give [Pt(6){&mgr;(3)-Ir(CO)(2)}(&mgr;(3)-AuPPh(3))(&mgr;-CO)(6)(&mgr;-dppm)(3)]. The new cluster complexes are characterized by NMR and IR spectroscopies, and Pt(6)(&mgr;(3)-AuPiPr(3))(2)(&mgr;-CO)(6)(&mgr;-dppm)(3) is also characterizedby an X-ray structure determination.