CHIRAL METAL-COMPLEXES .43. COBALT(III) COMPLEXES OF NOVEL ASYMMETRICTETRADENTATE AND PENTADENTATE AMINOPOLYPICOLYL LIGANDS

The syntheses of the two novel chiral amines, N,N'-di(2-picolyl)-1R, 3 S-diamino-1,2,2-trimethylcyclopentane (R,S-pictmcp) and -di(2-picolyl) -amino-N-(2-picolyl)hexahydroazepine (S-ahazterpy), and their complexe s with Co(III) are reported. Coordination of the tetradentate R,S-pict mcp is shown to be highly stereoselective, with only the Delta-beta is omer of [Co(R,S-pictmcp)CO3]ClO4)(2) . 2H(2)O, 2H(2)O, being isolated. Assignment of stereochemistry was made using a combination of CD and NMR techniques. In the preparation of [Co(S-ahazterpy)Cl] (ClO4)(2) . 2H(2)O, containing the pentadentate polyamine, a single isomer (trans- equatorial) was obtained. The yield, however, was low, and no inferenc e is made as to the extent of any stereoselectivity in this case. CD a nd NMR data are presented for both species and discussed in relation t o assigned stereochemistries.