DIFFERENT COORDINATION MODES OF THE LIGAND SPPH2!- IN COMPLEXES OF PD-II AND PT-II - CRYSTAL-STRUCTURES OF (PD(MU-SPPH2)(C6F5)(PPH3))2! AND PD(SPPH2)(PPH3)2!CLO4.CH2CL2

The neutral complexes {M(mu-SPPh2)(C6F5)(PR3)}2! (M = Pd or Pt; PR3 = PPh3 or PPh2Et) containing the P,S-bridging SPPh2!- have been synthe sised by reaction of the corresponding acetylacetonate (acac) derivati ves M(C6F5)(acac-O,O')(PR3)! with HP(S)Ph2. However, the reaction of the cationic complexes M(acac-O,O')(PPh3)2!ClO4 (M = Pd or Pt) with H P(S)Ph2 affords mononuclear M(SPPh2)(PPh3)2!ClO4 in which the SPPh2! - ligand is co-ordinated as a P,S-chelate. The anionic complex NBu4!2 {Pd(mu-SPPh2)(C6F5)2}2! has also been synthesised. The crystal struct ures of {Pd(mu-SPPh2)(C6F5)(PPh3)}2! and Pd(SPPh2)(PPh3)2!ClO4.CH2Cl 2 have been determined by X-ray diffraction methods; the former adopts a boat conformation.