Synthesis, spectral and biological investigations of 5(2′-hydroxyphenyl)-3-(4-substituted-phenyl) pyrazolinates of cobalt(II) and their addition complexes with N, P donor ligands

Abstract

5(2 0 -Hydroxyphenyl)-3-(4-substituted-phenyl)pyrazolinates of cobalt(II) of the type (C 15 H 12 N 2 OX) 2 Co [here substituted group X is -H, -Cl, -CH 3 or -OCH 3 ] have been synthesized by reaction of anhydrous cobalt(II)chloride with the sodium salt of the pyrazolines in 1 : 2 molar ratio. Their addition complexes with N and P donor ligands [2, 2 0 -bipyridine, 1, 10-phenanthroline and triphenylphosphine] were prepared in 1 : 1 molar ratio. The newly synthesized complexes were characterized by elemental analyses, molecular weight measurement, magnetic susceptibility, IR, electronic, 31 P NMR and FAB mass spectra. All complexes are amorphous as determined by XRD. Tetrahedral geometry around cobalt(II) has been suggested, confirming the presence of two pyrazoline bidentate ligands, cobalt(II)5-(2 0 -hydroxyphenyl)-3-(4-substituted-phenyl)pyrazolinates. Upon ligand addition, pyrazoline changes to monodentate. The bidentate and monodentate behavior of pyrazoline ligands was confirmed by IR spectral data. The metal complexes and their adducts exhibit good antibacterial and antifungal activity, better than the pyrazolines.

Synthesis, spectroscopic and biological studies on the new symmetric Schiff base derived from 2,6-diformyl-4-methylphenol with N-aminopyrimidine

“…Additionally, when all the antimicrobial MIC values were compared, the ligand and Cu(II) complex displayed the highest antimicrobial efficacy with MIC values ranging between 20-40 mg mL À1 . Accordingly, the data obtained from this investigation were in good agreement with the previous studies that expressed the metal complexes with Schiff bases have greater activity toward microorganisms [7][8][9]. Finally, it suggested that the reason for this higher antimicrobial efficacy can be related to the inhibition several structural enzymes, which play a key role in vital metabolic pathways of the microorganisms.…”

“…The results of this investigation revealed that the ligand, Cu(II), Ni(II) and Co(II) complexes possessed higher antimicrobial activity, although it was generally reported that free ligands shown lower activity than complexes [7][8][9]27,28]. Additionally, when all the antimicrobial MIC values were compared, the ligand and Cu(II) complex displayed the highest antimicrobial efficacy with MIC values ranging between 20-40 mg mL À1 .…”

“…On the other hand, purines and pyrimidines and their derivatives are known for growth factor analogs and they have been used for treatment of bacterial, viral and fungal infections. In recent years, several studies were reported that metal complexes with Schiff bases are extremely important due to their considerable antifungal, antibacterial and antitumor activities [7][8][9]. A number of previous studies proposed that pyrimidines and their complexes displayed effective and selective antimicrobial activity against bacteria, fungi and virus [10][11][12].…”