[PT-2(DPPF)(2)(MU-S)(2)] AS A HETEROMETALLIC LIGAND - SIMPLE ASSEMBLYOF AN ELECTROACTIVE INTERPOLYMETALLIC COMPLEX [PT2TL(DPPF)(2)(MU(3)-S)(2)]X (X=NO3, PF6) (DPPF=1,1'-BIS(DIPHENYLPHOSPHINO)FERROCENE)

Facile complexation of a heterometallic ligand Pt-2(dppf)(2)(mu-S)(2) (dppf = 1,1'-bis(diphenylphosphino)ferrocene) with TlNO3 gives [Pt2Tl( dppf)(2)(mu(3)-S)(2)]NO3, which metathesizes with NH4PF6 to give its P F6- salt. This Lewis acid-base addition forms the basis of an assembly of electroactive interpolymetallic aggregates which are constituted o f an unsaturated fragment of a p-block metal and two redox-active Pt-I I cores, linked by two flexible sulfide bridges. Intermetallics of oth er metals, viz. Pt-2(dppf)(2)(mu(3)-S)(2)InCl3 and [Pt-2(dppf)(2)(mu(3 )-S)(2)Pb(NO3)]NO3, are similarly assembled. The X-ray molecular struc ture of [Pt2Tl(dppf)(2)(mu(3)-S)(2)]PF6 reveals a side-on attachment o f the ligand thereby exposing an ''empty space'' on the Tl-I atom. [Pt 2Tl{(C(5)H(4)PPh(2))(2)Fe}(2)(S)(2)]PF6: a 17.795(4), b 10.553(2), c 1 7.936(4) Angstrom; monoclinic; P2/n; Z 2. No direct Pt-Tl bonding is e nvisaged but the close contacts between the two atoms (3.389(1) Angstr om) enable Pt-195-Tl-203/205 coupling to be observed in the Pt-195 NMR spectrum. The electrochemical behavior of this complex is examined by cyclic voltammetry in 1,2-dichioroethane. The complex undergoes an ap parently irreversible two-electron-transfer process of the Tl+ center and a quasi-reversible two-electron-transfer process involving two non interacting ferrocenyl moieties.