Synthesis, Characterization and Identification of Mononuclear Transition Metals Complexes 1, 3-Bis-((5-methyl-1H-Imidazol-4-yl) Methyleneamino) Propan-2-ol Ligand

Abstract

The ligand 1,3-bis-((5-methyl-1H-imidazol-4-yl)methyleneamino)propan-2-ol (H3L) derived from 1,3-diaminopropan-2-ol and 5-methyl-1H-imidazole-4-carbaldehyde has been synthetized and used to prepare five complexes in which the ligand acts in tetradentate fashion. Complexes formulated as [Mn(H3L)(H2O)2].2SCN (1), [(Co(H3L)].2SCN (2), [(Ni(H3L)].2SCN (3), [(Cu(H3L)(NO3)].(NO3).2H2O (4), and [(Zn(H3L)].2SCN (5) were synthesized by mixing an equimolar amount of an methanol solution containing the appropriate nitrate salt and KSCN, in 1:2 ratio, in the case of 1, 2, 3 and 5 and an ethanol solution containing the appropriate ligand H3L. The complex 4 has been synthetized in the absence of KSCN. In all the complexes the ligand acts in its neutral form and in tetradentate fashion, its hydroxy group remaining free and non-deprotonated. The ligand is coordinated to metal ion through two azomethine nitrogen atoms and two pyrazole sp2 nitrogen atoms. The complexes are characterized by elemental analysis, conductance and room temperature magnetic moments measurements, UV–Vis and IR spectroscopic studies. The structure of the copper(II) complex 4 is confirmed by X-ray diffraction. 4 crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 8.5459 (3) Å, b = 10.9177 (3) Å, c = 22.4562 (6) Å, b = 96.954 (3)°, V = 2079.79 (11) Å3, Z = 4, R1 = 0.050 and wR2 = 0.131. The CuII cation in N4O inner is situated in a distorted square pyramidal environment.