Manganese(II) complexes containing the tridentate ligands 2,6-bis[1-(phenylimino)ethyl]pyridine, L1, or 2,6-bis[1-(4-methoxyphenylimino)ethyl]pyridine, L2. The molecular structures of five-co-ordinate [MnBr2L1] and the zinc analogue [ZnCl2L1]