Metal Complexes Containing Six-membered Chelate Rings V. Preparation and Structure of Oxalato Complexes of Cobalt(III) with Substituted 3,7-Diaza- 1,9-nonanediamine Derived from 2,4-Pentanediamine

Abstract

Abstract The syntheses, resolution and structure of three oxalato complexes of cobalt(III) with tetramine ligand, R(4), R(6)- and R(4), S(6)-4,6-dimethyl-1,9-nonanediamine (RR- and RS-2,3″, 2-tet), and R(6), S(8)-6,8-dimethyl-2,5,9,12-tetraazatridecane (N,N′-Me2-RS-2,3″,2-tet) are reported. Only one geometrical isomer (cisβ) was isolated for each complex, [Co(ox)(N,N′-Me2-RS-2,3,″,2-tet)]+, [Co(ox)RS-2,3″,2-tet]+ and [Co(ox)RR-2,3″,2-tet]+· The central six-membered chelate rings of (−)546-cis β-[Co(ox)(N,N′-Me2-RS-2,3″,2-tet]+ and (−)546-cis β-[Co(ox)(RS-2,3″,2-tet)]+ take a chair conformation with two equatorial methyl groups, and that of (−)546-cis β-[Co-(ox)(RR-2,3″,2-tet)]+ a chair conformation with an axial and equatorial methyl group.