Transition metal complexes of the novel tridentate di-2-pyridylmethanamine (dipa)

The transition metal complexes (M(dipa)2)n+, where dipa = di-2-pyridylmethanamine and M = Fe(III), Fe(II), Co(III), Ni(II) and Cu(II) were synthesized. An equilibrated mixture of rac and meso isomers were identified in (M(dipa)2)n+. Pyridyl groups were found to stabilize more types of complexes than its triamine analog. Moreover, molecular mechanics calculations showed that steric effects determined preference for the rac isomer.