Inorganic Chemistry, Vol.34, No.26, 6425-6429, 1995
(Pt-2(Dppf)(2)(Mu-S)(2)) as a Heterometallic Ligand - Simple Assembly of 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 PF6- salt. This Lewis acid-base addition forms the basis of an assembly of electroactive interpolymetallic aggregates which are constituted of an unsaturated fragment of a p-block metal and two redox-active Pt-II cores, linked by two flexible sulfide bridges. Intermetallics of other 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 structure of [Pt2Tl(dppf)(2)(mu(3)-S)(2)]PF6 reveals a side-on attachment of the ligand thereby exposing an "empty space" on the Tl-I atom. [Pt2Tl{(C(5)H(4)PPh(2))(2)Fe}(2)(S)(2)]PF6 : a 17.795(4), b 10.553(2), c 17.936(4) Angstrom; monoclinic; P2/n; Z 2. No direct Pt-Tl bonding is envisaged but the close contacts between the two atoms (3.389(1) Angstrom) 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 apparently irreversible two-electron-transfer process of the Tl+ center and a quasi-reversible two-electron-transfer process involving two noninteracting ferrocenyl moieties.
Keywords:PLATINUM SULPHIDO-COMPLEXES;BRIDGING SULFIDO-LIGANDS;GROUP LEWIS-ACIDS;MAIN-GROUP;HETEROPOLYMETALLIC COMPLEXES;MOLECULAR-STRUCTURES;CRYSTAL-STRUCTURES;CHEMISTRY;PT2(MU-S)2(PPH3)4;METALLOLIGAND