Enantiomeric discrimination in coordination of sulfoxides to platinum(II): X-ray structure of the kinetically over thermodynamically favoured erythro cis-dichloro-bis(methyl-p-tolylsulfoxide)platinum(II)

The erythro bis-sulfoxide complex cis-[PtCl2{R-S(O)MeTol(p)}{S-S(O)MeTol(p)}] has been isolated, as the kinetically preferred product, in the reaction of K2PtCl4 with methyl-p-tolylsulfoxide in water/methanol. The crystal and molecular structure of the title complex has been determined by X-ray diffraction methods and compared with those of the thermodynamically preferred three species cis-[PtCl2{S(O)R'R ''}(2)] (R' = Me, R '' = Ph or Tol(p)). Crystal data: monoclinic, space group P2(1)/n, a = 19.081(3), b = 5.992(1), c = 19.398(3) Angstrom, beta = 119.05(2)degrees, Z = 4, R = 0.0355. The kinetics of isomerization in chloroform of the erythro cis-[PtCl2{S(O)MeTol(p)}(2)] to a 1:3 mixture of erythro and threo species has been investigated. (C) 1997 Elsevier Science S.A.