Structural characterisation of metal complexes containing 1-[(4-methylphenyl)sulfonamido]-2-[(2-pyridylmethylene)amino]benzene
Abstract
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}, L1, and {1-[(4-methylphenyl)sulfonyl]-2-(2-pyridyl)-2,3-dihydro-1H-benzo[d]imidazole}, L2, but not to the expected Schiff base 1-[(4-methylphenyl)sulfonamido]-2-[(2-pyridylmethylene)amino]benzene, HL3. Two kinds of complexes, containing the potentially tridentate and monoanionic [L3]− 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 L1 and p-toluenesulfonic acid, using metal plates as the anode. Metal complexes of composition ML32(H2O)n (M = Mn, Co, Cu, 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 1H NMR spectroscopy. CuL3(p-Tos)(H2O), 1, ZnL3(p-Tos)(H2O), 2, CoL32, 3, CuL32, 4 and ZnL32·2CH3CN, 5, were also crystallographically characterised.