A Ditopic Phosphane-decorated Benzenedithiol as Scaffold for Di- and Trinuclear Complexes of Group-10 Metals and Gold

The ability of 3-(diphenylphosphinomethyl)-benzene-1,2-dithiol (pbdtH(2)) to act as ditopic ligand was probed in reactions with selected group-10-metal complexes. Reactions with [(cod)PdCl2] afforded a mixture of products identified as [Pd(pbdtH)(2)], [Pd-2(mu(2)-pbdt)(2)] and [Pd-3(mu(2)-pbdt)(2)Cl-2]. The polynuclear complexes could be isolated after suitably adjusting the reaction conditions, and heating of a mixture in a microwave reactor effected partial conversion into a further complex [Pd-3(mu(2)-pbdt)(3)]. Reaction of pbdtH(2) with [Ni(H2O)(6)Cl-2] gave rise to a complex [Ni-2(mu(2)-pbdt)(2)], which was shown to undergo two reversible 1e(-)-reduction steps. Reaction of [Pd(pbdtH)(2)] with [Au(PPh3)Cl] afforded heterotrinuclear [PdAu2(mu(2)-pbdt)(2)(PPh3)]. All complexes were characterized by analytical, spectroscopic and single-crystal X-ray diffraction studies. Their molecular structures confirm the ability of the pbdt(2-) unit to support simultaneous P,S- and S,S-chelating coordination to two metal centers.Peer reviewe

New Selective Synthesis of Dithiaboroles as a Viable Pathway to Functionalized Benzenedithiolenes and Their Complexes

A synthetic protocol to synthesize 2-bromobenzo-1,3,2-dithiaboroles in one step from easily accessible benzene bis­(isopropyl thioether)­s has been developed. The reaction is remarkably specific in converting substrates with two adjacent ^<i>i</i>PrS moieties while leaving isolated thioether functions and other functional groups intact. On the basis of the spectroscopic detection or isolation of reaction intermediates, a mechanistic explanation involving a neighbor-group-assisted dealkylation as a key step is proposed. The resulting products featuring one or two dithiaborole units were isolated in good yields and fully characterized. Subsequent methanolysis, which was carried out either as a separate reaction step or in the manner of a one-pot reaction, gave rise to functionally substituted benzenedithiols. The feasibility of a methylphosphoryl-substituted benzenedithiol to act as a dianionic S,S-chelating ligand was demonstrated with the formation of paramagnetic Ni­(III) and Co­(III) complexes. Selective reduction of the phosphoryl group afforded a rare example of a phosphino dithiol which was shown to act as a monoanionic P,S-bidentate ligand toward Pd­(II). All complexes were characterized by spectral data and X-ray diffraction studies, and the paramagnetic ones also by superconducting quantum interference device magnetometry