PPh(2-C6H4S)2 as a pincer ligand in nickel(II) and palladium(II) complexes — x-ray structure of [Ni{PPh(C6H4S)2}(PPh2Me)], [Pd2(µ-dppe){PPh(C6H4S)2}2] and [Ni{PPh(C6H4S)2}]2

The phosphanylthiol PPh(2-C 6 H 4 SH) 2 reacts with the Ni II and Pd II complexes [MCl 2 L 2 ] in the presence of NaOEt to give the mononuclear derivatives [M{PPh(C 6 H 4 S) 2 }L] [M = Ni, L = PPh 3 (1), PPh 2 Me (2); M = Pd, L = PPh 3 (3)]. The analogous reaction starting with complexes containing bidentate ligands [MX 2 (L-L)] produces different results depending on the ligand used. The complexes [M{PPh(C 6 H 4 S) 2 }(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 2 (μ-dppe){PPh(C 6 H 4 S) 2 }] [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 6 H 4 S) 2 }(phen)] [M = Ni (8), Pd (9)] are obtained, but when 2,2′-bipyridine is used the dinuclear compounds [M{PPh(C 6 H 4 S) 2 }] 2 [M = Ni (10), Pd (11)] are isolated instead. Complexes 10 and 11, which can be obtained starting from NiCl 2 or [PdCl 2 (NCPh) 2 ] 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.