Open-Ended Metallodithiolene Complexes with the 1,2,4,5-Tetrakis(diphenylphosphino)benzene Ligand: Modular Building Elements for the Synthesis of Multimetal Complexes.

Open-ended, singly metalated dithiolene complexes with 1,2,4,5-tetrakis(diphenylphosphino)benzene (tpbz) are prepared either by ligand transfer to [ClM(tpbz)] from (RCS)SnR' (R = CN, R' = Me; R = Me, R' = Bu) or by a direct reaction between tpbz and [M(SCR)] (M = Ni, Pd, Pt; R = Ph, -anisyl) in a 1:1 ratio. The formation of dimetallic [(RCS)M(tpbz)M(SCR)] attends these syntheses in modest amounts, but the open-ended compounds are readily separated by silica chromatography. As affirmed by X-ray crystallographic characterization of numerous members of the set, the [(RCS)M(tpbz)] compounds show dithiolene ligands in their fully reduced ene-1,2-dithiolate form conjoined with divalent Group 10 ions.

Redox-Active Metallodithiolene Groups Separated by Insulating Tetraphosphinobenzene Spacers.

Compounds of the type [(SCR)M(μ-tpbz)M(SCR)] (R = CN, Me, Ph, p-anisyl; M = Ni, Pd, Pt; tpbz = 1,2,4,5-tetrakis(diphenylphosphino)benzene) have been prepared by transmetalation with [(SCR)SnR'] reagents, by direct displacement of dithiolene ligand from [M(SCR)] with 0.5 equiv of tpbz, or by salt metathesis using Na[SC(CN)] in conjunction with XM(μ-tpbz)MX (X = halide). X-ray crystallography reveals a range of topologies (undulating, chair, bowed) for the (SC)M(PCP)M(SC) core.

Synthesis, structures, and properties of 1,2,4,5-benzenetetrathiolate linked group 10 metal complexes.

Dimetallic compounds [(P-P)M(S(2)C(6)H(2)S(2))M(P-P)] (M = Ni, Pd; P-P = chelating bis(phosphine), 3a-3f) are prepared from O=CS(2)C(6)H(2)S(2)C=O or (n)Bu(2)SnS(2)C(6)H(2)S(2)Sn(n)Bu(2), which are protected forms of 1,2,4,5-benzenetetrathiolate. Selective monodeprotections of O=CS(2)C(6)H(2)S(2)C=O or (n)Bu(2)SnS(2)C(6)H(2)S(2)Sn(n)Bu(2) lead to [(P-P)Ni(S(2)C(6)H(2)S(2)C=O)] or [(P-P)Ni(S(2)C(6)H(2)S(2)Sn(n)Bu(2))]; the former is used to prepare trimetallic compounds [(dcpe)Ni(S(2)C(6)H(2)S(2))M(S(2)C(6)H(2)S(2))Ni(dcpe)] (M = Ni (6a) or Pt (6b); dcpe = 1,2-bis(dicyclohexylphosphino)ethane). Compounds 3a-3f are redox active and display two oxidation processes, of which the first is generally reversible.