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

The 84-electron hexaplatinum cluster complex [Pt(6)(-CO)(6)(-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)((3)-ML)(2)(-CO)(6)(-dppm)(3)](2+) or [Pt(6)((3)-InX(3))(2)(-CO)(6)(-dppm)(3)] or 88-electron clusters [Pt(6)((3)-Tl)(2)(-CO)(6)(-dppm)(3)](2+) and [Pt(6)((3)-Hg)(2)(-CO)(6)(-dppm)(3)], respectively. The mercury cluster is oxidized by CH(2)I(2) to give the known 86-electron cluster [Pt(6)((3)-HgI)(2)(-CO)(6)(-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){(3)-Ir(CO)(2)}(-CO)(6)(-dppm)(3)](-), which reacts with [Ph(3)PAu](+) to give [Pt(6){(3)-Ir(CO)(2)}((3)-AuPPh(3))(-CO)(6)(-dppm)(3)]. The new cluster complexes are characterized by NMR and IR spectroscopies, and [Pt(6)((3)-AuPiPr(3))(2)(-CO)(6)(-dppm)(3)](2+) is also characterizedby an X-ray structure determination.