Structural Study and Antimicrobial Evaluation of Some Transition Metal Complexes with Pyrazole Base Ligand 5-{[(E)-(1,4-Diphenyl-1H-Pyrazol-3-Yl) Methylidene]Amino}-1,3-Thiazol-4-Ol

Anew poly dentate ligand5-{[(E)-(1,4-diphenyl-1H-pyrazol-3-yl)methylidene]amino}-1,3-thiazol-4-ol was prepared by stepwise reactions of phenylhydrazone derivative A with POCl₃ in DMF as oxidizing agent to afford 1,4-diphenyl-1H-pyrazole derivative A2 followed condensation reaction with 2-amino-1,3,4-thiazol-4-4y-ol. The present pyrazole LH was used as bidentate Lewis base to prepare solid complexes with manganese (II), cobalt (II), nickel (II), copper (II) and cadmium (II). All the complexes have identified with the help of (C.H.N. elemental analyses), flame atomic absorption spectroscopy and spectral techniques of H,C¹³ NMR, FTIR and UV-visible spectra. Furthermore the molar conductance of 0.001 M solutions in acetonitrile and magnetic susceptibility were performed to elucidate the proposed geometry and structures of the prepared complexes. The antimicrobial activity of the ligand and complexes solutions in DMSO control were screened via two positive and two negative bacteria. The observed results of inhibition zone in millimeters units revealed the enhancement of activity of copper and cadmium (II) complexes of 20 ppm in compared with the low biological activity of the free ligand.