Seven novel transitional metallic copper complexes of seven new acyl pyrazolone Schiff bases have been synthesized in the nonaqueous solvent. These seven Schiff bases were derived from 1-(p-chlorophenyl)-3-phenyl-4-benzoyl-pyrazolone-5 and aniline (HS¹), parachloroani-line (HS²), parabromoaniline (HS³), furfuryl amine (HS⁴), p-methoxy aniline (HS⁵), p-ethoxyaniline (HS⁶) and naphthyl-amine (HS⁷), respectively. The general formula of complexes was confirmed to be [Cu(S)₂] (S＝S¹, S², S³, S⁴, S⁵, S⁶, S⁷) based on elemental analysis, complexometric titration, mass spectra and molar conductance value. Their molecular structures were characterized by IR, TG, ¹HNMR and liquid chromatography coupled with mass spectrometry, and the antibacterial ac-tivities of these seven Schiff bases and their complexes were also investigated with the oxford cup plate as-say method. The characterization results showed that the isomers of seven ligands existed differently under different testing conditions. The ketoform structure might change into the enolform structure after coordina-tion and bonded with copper central ion by enolic oxygen negative ion losing one proton and nitrogen atom of imine group in bis-cog form. The results of antibacterial activity experiment indicated that all compounds were all resistant to four different bacteria with various degrees under different concentrations. The antibac-terial action of the complexes was generally stronger than that of the ligands. The varying trend of antibacte-rial capability followed the concentration effect, the maximal diameter could be 16.0 mm under the concen-tration of 3.0 mg•mL^－1.

Key words: Schiff base, copper complex, synthesis, antibacterial activity