Ruthenium(II) Dihalogeno-complexes with (C6H5)2P(CH2)2SR Ligands (R = CH3, C2H5, and cyclo-C6H11) and their Reactions with Carbon Monoxide and Acetonitrile. The Crystal Structure of trans,cis,cis-[RuCl2{(C6H5)2P(CH2)2S(cyclo-C6H11)-P,S}2]

The reaction between cis-[RuCl2(dmso)(4)] (dmso=dimethylsulfoxide) and the phosphine-thioether ligands Ph2P(CH2)(2)SR(PSR;R=Me PSMe, R=Et PSEt, or R=cyclo-C6H11 PSCy) affords the ruthenium(II) six-coordinate derivatives [RuCl2(PSR-P,S)(2)]. All complexes have been characterised by means of UV-Vis, IR and H-1, C-13 and P-31 NMR spectroscopy. Three of the five possible isomers (cis,cis,cis,cis,cis,trans and trans,cis,cis) of the octahedral complexes have been obtained. The crystal structure of trans,cis,cis-[RuCl2(PSCy-P,S)(2)] has been determined by single-crystal X-ray diffraction analysis. Also cis,cis,trans-[RuI2(PSR-P,S)(2)] derivatives have been prepared from the corresponding dichloro-compounds by halide metathesis. The reaction of [RuCl2(PSR-P,S)(2)] with carbon monoxide gives cationic [RuCl(CO)(PSR-P,S)(2)](+) or neutral [RuCl2(CO)(PSCy-P)(PSCy-P,S)] derivatives via Ru-Cl or RuS bond cleavage, respectively. in the case of the diiodo-derivatives the corresponding monocarbonyls [RuI(CO)(PSR-P,S)(2)](+) are obtained. The reaction of cis,cis,cis-and cis,cis,trans-[RuCl2(PSMe-P,S)(2)] isomers with acetonitrile has also been investigated, and both cis,cis- and cis,trans-[Ru(MeCN)(2)(PSMe-P,S)(2)](2+) have been obtained. Both diacetonitrile compounds slowly react with CO yielding the corresponding [Ru(CO)(MeCN)(PSMe-P,S)(2)](2+) derivatives with retention of configuration.