STEREOSELECTIVE OXIDATIVE-ADDITION REACTION OF MOLECULAR-IODINE AND MERCURY(II) HALIDES TO RHODIUM DITHIOLATE COMPOUNDS - CRYSTAL-STRUCTURE OF [RH-2(MU-S(CH2)(2)S)CL-2(CO)(2)(PPH(3))(2)]

The binuclear complexes [Rh2{mu-S(CH2)(2)S}(L(2))(2)][L(2) = cycloocta-1.5-diene (cod) 1, L(2) = (CO)(2) 2] and [Rh-2{mu-S(CH2)(2)S}(CO)(2)(PR(2))(2)] (R = Ph 3 or OPh 4) have been prepared and oxidative addition of the etectrophiles I-2 and HgX(2) (X = Cl or I) investigated. Compounds 3 and 4 undergo stepwise addition of molecular iodine to yield the symmetrical complexes [Rh-2{mu-S(CH2)(2)S}I-n(CO)(2)(PR(3))(2)] [n = 2. R = Ph 5, R = OPh 6; n = 4, R = Ph 7, R = OPh 8]. However, interaction of 3 with HgX(2) (X = Cl or I) affords the unsymmetrical compounds [Rh-2{mu-S(CH2)(2)S}X(2)(CO)(2)(PPh(3))(2)] (X = Cl 9 or I 10). The crystal structure of 9 has been determined by X-ray diffraction methods.