Reaction of [Ru(CO) 2Cl 2] n with ligands Ph 2P(CH 2)nP(S)Ph 2 (n0/1(a), 2(b), 3(c), 4(d)) in 1:1 molar ratio produces complex cis[Ru(CO)
2Cl 2(PS/S)](1a)(PS/S0/h 2-(P, S) coordinated) and cis-[Ru(CO)2Cl2(P/S)](1b/d)(P/S0/h 1-(P) coordinated), while 1:2
molar ratio yields complex of the type cis-[Ru(CO) 2Cl 2(P/S) 2](2a/d). The complex 2a undergoes partial decarbonylation reaction
inCH 2Cl 2/hexanesolutiontogiveanewchelatedcomplex[Ru(CO)Cl(PS/S) 2]Cl(2a?).AbstractionofhalidewithAgClO 4fromthe
non-chelated complexes 1b/d and 2a/d afford corresponding chelated complexes [Ru(CO) 2Cl(PS/S)](ClO 4)(3b/d) and
[Ru(CO) 2(PS/S) 2](ClO 4)2(4a/d). The molecular structure of the complex 2a? has been determined by single crystal X-ray
diffraction. The ruthenium atom is at the centre of slightly distorted octahedral structure having the two phosphorus atoms of the
twochelatedP,Scoordinatedligandsattrans toeachother,oneCOgroupandClatomcompletingthecoordinationsphere.Other
complexes have been characterized by elemental analysis, IR, 1H and 31P {H} NMR spectroscopy
