PPh(2-C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF> as a Pincer Ligand in Nickel(II) and Palladium(II) Complexes — X-ray Structure of [Ni{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}(PPh<INF>2</INF>Me)], [Pd<INF>2</INF>(μ-dppe){PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}<INF>2</INF>] and [Ni{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}]<INF>2</INF>

The phosphanylthiol PPh(2-C<INF>6</INF>H<INF>4</INF>SH)<INF>2</INF> reacts with the Ni^II and Pd^II complexes [MCl<INF>2</INF>L<INF>2</INF>] in the presence of NaOEt to give the mononuclear derivatives [M{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}L] [M = Ni, L = PPh<INF>3</INF> (1), PPh<INF>2</INF>Me (2); M = Pd, L = PPh<INF>3</INF> (3)]. The analogous reaction starting with complexes containing bidentate ligands [MX<INF>2</INF>(L-L)] produces different results depending on the ligand used. The complexes [M{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}(dppm)] [M = Ni (4), Pd (5)], with an unligated phosphorus atom in the diphosphane are obtained with bis(diphenylphosphanyl)methane (dppm), while the dinuclear complexes [M<INF>2</INF>(μ-dppe){PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}] [M = Ni (6), Pd (7)] are isolated in the case of 1,2-bis(diphenylphosphanyl)ethane (dppe). With 1,10-phenanthroline (phen), the complexes [M{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}(phen)] [M = Ni (8), Pd (9)] are obtained, but when 2,2'-bipyridine is used the dinuclear compounds [M{PPh(C<INF>6</INF>H<INF>4</INF>S)<INF>2</INF>}]<INF>2</INF> [M = Ni (10), Pd (11)] are isolated instead. Complexes 10 and 11, which can be obtained starting from NiCl<INF>2</INF> or [PdCl<INF>2</INF>(NCPh)<INF>2</INF>] respectively, afford complexes 1−7 when treated with the respective phosphanes in the appropriate stoichiometries. The structures of 2, 7 and 10 have been confirmed by X-ray analysis.