Synthesis, Characterization, Study of antimicrobial activity and Evaluation of stability constants of Cu(II) complexes with ligands 2-(4,5dihydro-1,5-diphynyl-1H-pyrazole-3yl)phenol derivatives

Abstract

The synthesis and characterization of an unique tetradentate Schiff bases were presented in this report namely: 2-(4,5dihydro-1,5-diphynyl-1H-pyrazole-3-yl)phenol (HL 1 ) and 2-(4,5dihydro-5-(4-methoxyphenyl)-1-phynyl-1H-pyrazole-3yl)phenol (HL 2 ) and their copper complexes. On the basis of elemental analysis, magnetic susceptibility, conductivity, electronic, IR, ESR spectral data and powder X-ray powder diffraction observations indicated that for investigated complexes have been proposed octahedral geometry. The stability constants were determined using the p H metric technique. At various temperatures, a series of titrations using standard NaOH solution were performed. a temperature of 25°C and 30 0 C. On the basis of experimental results and analysis it is observed that the values of proton-ligand stability constants and metal-ligand stability constants were found to decrease with increase in temperature. The antimicrobial and antifungal activities of the studied ligands as well as their copper complexes were evaluated using the cup plate technique at various doses in DMSO solvent using the minimum inhibitory concentration (MIC) method. The research indicates that Cu(II) complexes have high microbial activity, whereas ligands (HL 1 ) and (HL 2 ) have moderate activity.