A novel chelate-assisted C−C bond formation on a Cd(II) complex of an asymmetric heptadentate(N7) tripodal Schiff base ligand

Cadmium(II) complexes of some potentially heptadentate tripodal Schiff base ligands with the general formula N{(CH2)nNdouble bond; length as m-dashCHC5H4N}2{(CH2)mNdouble bond; length as m-dashCHC5H4N}) (where n = m = 2, L222; n = 2, m = 3, L322; n = 3, m = 2, L332) have been studied. These ligands are products of the full condensation of a number of tripodal tetraamines with 2-pyridinecarboxaldehyde. An unusual reaction of an additional 2-pyridine-carboxaldehyde with a methylene group adjacent to the imine bond only during template preparation of [Cd(L332)]2+ was observed. The latter reaction is a novel chelate-assisted C−C bond formation because it is occurred only where a rigid five-membered chelate ring is present.