Structural characterisation of metal complexes containing 1-[(4-methylphenyl)sulfonamido]-2-[(2-pyridylmethylene)amino]benzene

The interaction of 2-pyridinecarboxaldehyde with N-tosyl-1,2-diaminobenzene leads to the isolation of two different products, (3-[ethoxy(2-pyridyl)methyl]-1-[(4-methylphenyl)sulfonyl]-2-(2-pyridyl)-2,3-dihydro-1H- benzo[d]imidazole), L-1, and {1-[(4-methylphenyl)sulfonyl]-2-(2-pyridyl)-2,3-dihydro-1H-benzo[d]imidazole}, L-2, but not to the expected Schiff base 1-[(4-methylphenyl)sulfonamidol-2-[(2-pyridylmethylene) amino]benzene, HL3. Two kinds of complexes, containing the potentially tridentate and monoanionic [L-3](-) as a ligand, were obtained by different routes. ML3(p-Tos(H2O)(n) complexes (p-TosH = p-toluenesulfonic acid; M = Co, Cu, Zn; n = 1-3) have been isolated by electrolysis of a solution phase composed of L-1 and p-toluenesulfonic acid, using metal plates as the anode. Metal complexes of composition ML23(H2O)(n) (M = Mn, Co, Cy Zn; n = 0-2) were obtained by template synthesis from M(acac)(2), 2-pyridinecarboxaldehyde and N-tosyl-1,2-diaminobenzene. All these compounds have been characterised by elemental analyses, magnetic measurements, IR, mass spectrometry and, in the case of M = Zn, by H-1 NMR spectroscopy. CuL3(p-Tos(H2O), 1, ZnL3(p-Tos)(H2O), 2, CoL23,3, CuL23,4 and ZnL23. 2CH(3)CN, 5, were also crystallographically characterised.