ABSTRACT
Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the dialkylating agents ClCH(2)C(O)CH(2)Cl or ClCH(2)C(=NNHC(O)NH(2))CH(2)Cl gives the dicationic di-µ-thiolate complexes [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+) or [Pt(2){µ-SCH(2)C(=NNHC(O)NH(2))CH(2)S}(PPh(3))(4)](2+), isolated as BPh(4)(-) salts and characterised by ESI mass spectrometry, NMR spectroscopy and single-crystal X-ray crystallography. Treatment of the complex [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+), which contains a [6.6.4] bicyclic system, with hydroxide ions results in deprotonation of a CH(2) group and rearrangement of the resulting monocation, giving [Pt(2)(µ-SCH(2)C(O)CHS}(PPh(3))(4)](+), isolated as its PF(6)(-) salt. An X-ray structure determination shows the complex to have a novel rearranged [6.5.5] bicyclic system containing a Pt-S-Pt-S-C five-membered ring with a Pt-C bond. The alkyl ligand has a high trans-influence, manifest in a long trans Pt-P bond and small (1)J(PtP) coupling constant to the trans PPh(3) ligand. Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the 2,4-dinitrophenylhydrazone derivative of 1,3-dichloroacetone leads to the closely related complex [Pt(2){µ-SCH(2)C(=NNHAr)CHS}(PPh(3))(3)Cl] [Ar = C(6)H(3)(NO(2))(2)] in which a PPh(3) ligand is substituted by a chloride.
ABSTRACT
The reactivity of the metalloligand [Pt2(micro-S)2(PPh3)4] towards a variety of copper(II)-ligand systems has been studied. Reaction of [Pt2(mu-S)2(PPh3)4] with copper(II) halide complexes [CuCl2L](L = 2,2'-bipyridine and 1,10-phenanthroline) gave trinuclear dicationic products [Pt2(mu-S)2(PPh3)4CuL]2+, and the 8-hydroxyquinolinate (hq) complex [Cu(hq)2] gave [Pt2(mu-S)2(PPh3)4Cu(hq)]+, isolated as their BPh4- or PF6- salts. Related cationic complexes with other ancillary amine ligands (1,2-diaminoethane, 1,2-diaminopropane, 1,2-diaminocyclohexane) were obtained by reactions of [Pt2(mu-S)2(PPh3)4] with CuCl2 and the amine. In contrast, reaction of [Pt2(mu-S)2(PPh3)4] with CuCl2 and NH3 in methanol gave the intensely blue methoxy-bridged dicopper complex [{Pt(2)(mu-S)2(PPh3)4Cu(OMe)}2]2+, isolated as its hexafluorophosphate salt. Copper beta-diketonate complexes reacted with [Pt2(mu-S)2(PPh3)4] giving [Pt2(mu-S)2(PPh3)4Cu(beta-diketonate)]+PF6- complexes, with the CH3COCHCOCH3(acac) and CF3COCHCO(2-thienyl)(tta) derivatives characterised by X-ray structure determinations. The local Cu(II) environment ranges from distorted square-planar to an intermediate form of square-planar and tetrahedral. The beta-diketonate derivatives show varying stability towards methanolysis, giving [{Pt2(mu-S)2(PPh3)4Cu(OMe)}2]2+.
