NEUTRAL AND ANIONIC BINUCLEAR PERHALOGENOPHENYL PLATINUM SILVER COMPLEXES WITH PT-]AG BONDS UNSUPPORTED BY COVALENT BRIDGES - MOLECULAR-STRUCTURES OF ((THT)(C6CL5)(C6F5)2- PTAG(PPH3)), (NBU4)((C6F5)4PTAG(THT)) AND (NBU4)-(CIS-(C6CL5)2(C6F5)2PTAG(THT)) (THT = TETRAHYDROTHIOPHENE)

Heterobinuclear complexes of general formula [L(C6Cl5)3-x(C6F5)xPtAg(PPh3)] [x = 2-0; L = tht (tetrahydrothiophene), PPh3 or pyridine (py)] 14-21 have been prepared by treating the anionic platinum derivatives [NBu4][PtL(C6F5)x(C6Cl5)3-x] with [Ag(OClO3)(PPh3)] (molar ratio 1:1) in dichloromethane. The anionic [NBu4][(C6F5)4PtAgL] (L = OEt2, PPh3 or tht) 22-24 and [NBu4][cis-(C6Cl5)2(C6F5)2PtAg(tht)] 25 have been obtained from the corresponding [NBu4]2[Pt(C6X5)2(C6X'5)2] and [Ag(OClO3)L] (molar ratio 1:1) in CH2Cl2-diethyl ether. The reaction between [NBu4][Pd(C6F5)3(tht)] and [Ag(OClO3)(PPh3)] renders Ag(C6F5) and cis-[Pd(C6F5)2(PPh3)(tht)]. The salts [NBu4]2[Pt(C6Cl5)4] and [NBu4]2[Pd(C6F5)4] react with [Ag(OClO3)(tht)] yielding [NBu4][Pt(C6Cl5)3(tht)] and [NBu4][Pd(C6F5)3(tht)], respectively. The reactions between [NBu4]2[Pt(C6F5)4] and [Ag(OClO3)(tht)] or [Ag(OClO3)(PPh3)] (molar ratio 1:2) render in the first case complex 24 while in the second an unstable material which evolves to [(Ph3P)(C6F5)3PtAg(PPh3)] 27 is obtained. The reaction between [NBu4]2[trans-PtCl2(C6X5)2] (X = F or Cl) and [Ag(OClO3)(tht)] or [Ag(tht)2]ClO4 have also been studied. The structures of [(tht)(C6Cl5)(C6F5)2PtAg(PPh3)] 14, [NBu4][(C6F5)4PtAg(tht)] 24 and [NBu4][cis-(C6Cl5)2(C6F5)2PtAg(tht)] 25 have been established by single-crystal X-ray diffraction studies. The complexes contain a strong Pt-->Ag bond [2.650(2), 14; 2.641(1), 24; and 2.692(2) angstrom, 25] unsupported by covalent bridges, and short contacts between the o-F or o-Cl atoms of the C6X5 (X = F or Cl) groups and the Ag atom are present. The relative strength of such contacts is discussed. Methods for the synthesis of mixed pentachloro-pentafluorophenyl starting complexes 1-13 have been investigated.