Synthesis, characterization, and 3D-molecular modeling and analysis of some copper(II) chelates in O, N-donor coordination pattern involving Schiff bases derived from 4-butyryl-3-methyl-1-phenyl-2-pyrazolin-5-one and some sulfa drugs

The synthesis of five new chelates of copper(II) of the general formula[Cu(LH)2(Cl)2], where LH = N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one)sulfamethoxazole (bumphp-smzH, I), N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one)sulfadimidine (bumphp-sdmH, II), N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one)sulfanilamide (bumphp-snmH, III), N-(4′-butyrylidine-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one)sulfamoxole (bumphp-smlH, IV) or N-(4′-butyrylidine-3′-methyl-1’-phenyl-2′-pyrazolin-5′-one)sulfaguanidine (bumphp-sgdH, V) has been carried out. The complexes have been characterized by elemental analyses, copper determination, molar conductance, magnetic and decomposition temperature measurements, electron spin resonance, thermogravimetry, infrared, and electronic spectral studies. A trans octahedral structure has been proposed for these complexes. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out for one of the representative compound,[Cu(bumphp-snmH)2(Cl)2] (3) to substantiate the proposed structure.