SUBSTITUTION OF CO BY PICOLINES AND AMINES IN RHCL(CO)(PR3)2 - SYNTHESIS AND CRYSTAL-STRUCTURE OF CIS-RHCL(3-PIC)(P(OPH)3)2

The title complex, cis-RhCl(3-pic){P(OPh)3}2 (3-pic = 3-picoline), has been prepared with two other isostructural rhodium complexes, respectively with 4-picoline and CH2 = CH-CH2NH2. The RhCl(3-pic){P(OPh)3}2 compound crystallizes in space group P1BAR with a = 10.531(6), b = 12.025(9), c = 15.943(8) angstrom, alpha = 83.01(5), beta = 79.46(4), gamma = 86.33(5)-degrees; Z = 2. The RhCl(amine){P(OPh)3}2 complexes were obtained in the reactions of [Rh(mu-OMe)(cod)]2, [Rh(mu-Cl)(cod)]2 (cod = cycloocta-1,5-diene) or RhCl(CO){P(OPh)3}2 with amines. CO substitution by amines in RhCl(CO)(PR3)2 complexes [PR3 = P(OMe)3, P(OPh)3, P(O-o-MeC6H4)3, P(O-m-MeC6H4)3, PEt2Ph, PEtPh2, PMe2Ph, PMePh2 or PPh3] is limited by steric properties of amine and PR3 ligands. 3-Picoline substitutes CO only in complexes with PR3 ligands with cone angle theta less-than-or-equal-to 140-degrees [16]. The rate of CO substitution by 2-picoline is less than half that by 3-picoline.