Two chelate-forming Schiff bases derived from 4-aminoantipyrine with 4-aminobenzoic acid and benzoin, namely (Z)-4-(4-amino-1,5-
dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylideneamino)benzoic acid (HL
1
) and 4-((E)-4-((E)-((R)-2-hydroxy-1,2-diphenylethylidene)amino)-
1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylideneamino)benzoic acid (H2L
2
) were prepared and complexed with copper(II), nickel(II),
cobalt(II), manganese(II) and mercury(II)chlorides in ethanol. The M(HL1
)2Cl2 and M(HL
2
)2 type complexes could be isolated. The ligands
and theirs metal complexes were characterized using elemental analysis, infrared and electronic,
1H and 13C NMR spectroscopy, molar
conductance and magnetic moment measurements. The measurements showed that the HL1
ligand is coordinated in their complexes with
N,N-bidendate mode, while HL2
ionic ligand in NNO tridentate pattern through the azomethine nitrogen, amino-group and the depotonated
hydroxyl group of benzoin. The stability constants of complexes were determined spectrophotometricaly. All the studies reveal a six
coordinated octahedral structure of M(HL
2
)2 type complexes. In vitro tests for antibacterial and antifungal activities showed that most of the
prepared compounds display a good activity towards S. aureus, E. coli, B. subtilis, P. aureginosa, A. niger, A. flavus, R. stolonifer and C.
albicans .
Key words: Benzoin; 4-aminobenzoic acid; 4-aminoantipyrine; Schiff bases, metal complexes; biological activity
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