Mixed carbonylcyclooctene complexes of rhodium(I). cis-cyclooctene as ligand

Abstract

The substitution reactions of carbonyl groups in [Rh(CO) 2Cl] 2, Rhacac(CO) 2, Rhoxq(CO) 2 (acac = acetylacetonate, oxq = 8-hydroxyquinolinate) by cis-cyclooctene, leading to the formation of [Rh(C 8H 14)(CO)Cl] 2, Rhacac- (C 8H 14)CO, Rhoxq(C 8H 14)CO respectively, are described. Other monoolefins examined do not displace carbonyl groups from rhodium(I) complexes. Mixed carbonylcyclooctene complexes are also formed in the ligand exchange reactions [Rh(CO) 2Cl] 2 + [Rh(C 8H 14) 2Cl] 2 and Rhacac(CO) 2 + Rhacac(C 8H 14) 2. On reaction with triphenylphosphine and triphenylstibine the mixed complexes give Rhacac(L)CO and Rhoxq(L)CO. (Stibine derivatives of this type have not previously been obtained). The chemical and spectroscopic evidence, as well as the thermodynamic data cited from the literature indicate that cyclooctene exhibits comparatively strong donor properties.