OXIDATIVE ADDITIONS OF DICHLOROMETHANE AND CYCLO-OCTASULFUR TO RHODIUM(I) COMPLEXES CONTAINING (2-AMINOETHYL)-DIMETHYLPHOSPHINE OR (2-AMINOETHYL)-DIPHENYLPHOSPHINE

The oxidative-addition reactions of dichloromethane and cyclo-octasulf ur with rhodium(I) complexes containing (2-aminoethyl)dimethylphosphin e (edmp) or (2-aminoethyl)diphenylphosphine (edpp) have bees examined. The reactions of [{RhCl(cod)}(2)] (cod = cycloocta-1,5-diene) with ed mp and with edpp in dichloromethane yield cationic adducts trans(Cl,C) cis(P,P')-[RhCl(CH2Cl)(edmp)(2)](+) and trans(Cl,C)cis(P,P')-[RhCl(CH2 Cl)(edpp)(2)](+) 2, respectively. X-Ray analyses of these complexes re vealed that the Rh-CI bond lengths are considerably elongated compared with those of the corresponding dichloro complexes trans(Cl,Cl')cis(P ,P')-[RhCl2(edmp)(2)](+) and trans(CI,Cl')cis(P,P')-[RhCl2(edpp)(2)]() due to the strong trans influence of the chloromethyl donor group. T he Rh-C bonds in complexes 1, 2 and trans-[RhCl(CH2Cl)(dmpe)(2)](+) ar e 2.050(7) < 2.078(7) < 2.162(2) Angstrom, respectively, This order re flects the differences in the steric bulk around rhodium(III) centre a s well. as the strength of the trans influence toward the trans-positi oned Rh-CI bond. Complex 2 reacted further with S-g to give a mixture of trans(P,N)-[Rh(S-4)(edpp)(2)](+) 3a and trans(P,N)-[Rh(S-5)(edpp)(2 )](+) 3b, however such a reaction does not occur for 1. On the other h and, direct addition of S-g to [Rh(edmp)(2)](+) in methanol resulted i n the formation of trans(N,N')-[Rh(S-4)(edmp)(2)](+) 4a and a small am ount of the S-5 complex 4b. The analogous reaction with [Rh(edpp)(2)]( +) gave a mixture of 3a and 3b. X-Ray analyses revealed that 3a and 3b are cocrystallized in the ratio of 1 : 1. The preparation of trans(N, N')-[Rh(O-2)(edmp)(2)](+) 5 is also described.