Syntheses and single-crystal X-ray structures of a series of monosubstituted cis,cis-1,3,5-triaminocyclohexane-based complexes

The four triimine compounds cis,cis-1,3,5-tris[(E)-(X)-benzylideneamino]cyclohexane [X = H (1); 3-hydroxy (2); 3,5-dimethoxy (3); 4-acetamido (4)] are synthesized by the condensation of cis,cis-1,3,5-triaminocyclohexane with a substituted aromatic aldehyde. Complexation of these ligands with metal salts (1 with Ni, Cu, and Zn salts; 2 and 3 with Cu salts; 4 with a Zn salt) causes a selective hydrolysis reaction producing new monoimine complexes. The resulting complexes are characterized by a combination of infrared spectroscopy, elemental analysis, mass spectrometry and, in the cases of the zinc complexes, H-1 NMR spectroscopy. The structures of all six complexes are confirmed by single-crystal X-ray crystallographic studies.