Jiten C. Patel

Dicoumarol complexes of Cu(II) based on 1,10-phenanthroline: Synthesis, X-ray diffraction studies, thermal behavior and biological evaluation

A series of Cu(II) complexes containing dicoumarol derivatives and 1, 10-phenanthroline have been synthesized. Structural and spectroscopic properties of ligands were studied on the basis of mass spectra, NMR ((1)H and (13)C) spectra, FT-IR spectrophotometry and elemental analysis, while physico-chemical, spectroscopic and thermal properties of mixed ligand complexes have been studied on the basis of infrared spectra, mass spectra, electronic spectra, powder X-ray diffraction, elemental analysis and thermogravimetric analysis. X-ray diffraction study suggested the suitable octahedral geometry for hexa-coordinated state. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S(*)), pre-exponential factor (A), enthalpy (H(*)) and Gibbs free energy (G(*)) have been calculated using Freeman-Carroll method. Ferric-reducing antioxidant power (FRAP) of all complexes were measured. All the compounds were screened for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Bacillus subtilis, while antifungal activity against Candida albicans and Aspergillus niger have been carried out. Also compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.

Thermal, kinetic, spectroscopic studies and anti-microbial, anti-tuberculosis, anti-oxidant properties of clioquinol and benzo-coumarin derivatives mixed complexes with copper ion

A series of six Cu(II) complexes of clioquinol with benzo-coumarin derivatives have been synthesized. Physico-chemical, spectroscopic, and thermal properties of the complexes have been studied on the basis of infrared spectra, mass spectra, NMR spectra, electronic spectra, elemental analyses, and thermogravimetric analyses. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S*), pre-exponential factor (A), enthalpy (H*), and Gibbs free energy (G*) have been calculated using Freeman-Carroll method. All the compounds were screened for their anti-bacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes, Bacillus subtilis, and anti-fungal activity against Candida albicans and Aspergillus niger. Ferric-reducing anti-oxidant power of all complexes were measured. Also the compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.Graphical abstractStructural, spectroscopic, and biological aspects of ligands and its metal complexes have been studied on the basis of mass spectra, NMR, FT-IR spectrophotometry, and elemental analyses. Thermal behavior and kinetic properties of complexes were discussed. The structure of compounds has been monitored for their in vitro anti-microbial, anti-oxidant, and anti-tuberculosis activity.

Cu(II) and Ni(II) complexes of coumarin derivatives with fourth generation flouroquinolone: synthesis, characterization, microbicidal and antioxidant assay

New Cu(II) and Ni(II) complexes of acetyl coumarin derivatives with gatifloxacin were synthesized. Characterization of the complexes was carried out by elemental analysis, FT-IR, FAB-MS, electronic spectra and magnetic measurement along with thermo gravimetric studies. Thermal study reveals the absence of coordinated water molecule in case of Cu(II) complexes. All the Cu(II) complexes were found more potent antibacterial activity compared to Ni(II) complexes. The antituberculosis data have shown that copper conjugation may be advantageous in designing highly effective drugs for antitubercular therapy. These complexes were also found to be potent antioxidizing agents comprising radical scavenging capability and ferric reducing abilities.

Cross-linked polyimides containing phenolic residue

Cross-linked polyimides containing phenolic residue were prepared by Diels–Alder (DA) reaction of Phenol-furfural resin with various bis(maleimides), in presence of tetrahydro-furan-acetone (50:50 v/v) mixture solvent and without solvent. The so-called DA adduct tetrahydrophthalimide intermediates obtained were aromatized in the presence of acetic anhydride. The resultant cross-linked polyimides were characterized by elemental analyses, IR spectral studies and thermogravimetry. The results show that produced polyimides exhibit good thermal stability. The glass reinforcement of produced cross-linked polyimides system affords the laminates with good mechanical properties.

Synthesis, Thermal, and Biological Studies of Newly Synthesized Cu(II) Complexes With Ciprofloxacin Based on Bromo-Coumarins Derivatives

The authors describe synthesis, characterization, and biological evaluation of Cu(II) complexes. Characterization of ligands has been carried out by elemental analysis, melting point, mass spectra, (1H & 13C) NMR, and FT-IR, while structure of metal complexes was confirmed by electronic spectra and FAB-mass spectral studies. Spectral studies confirm ligands is mono functional bidentate and octahedral environment around metal ions. Thermal behavior of Cu(II) complexes were investigated by means of TGA and magnetic measurements. The kinetic parameters are reported using the Freeman-Carroll method. Complexes were found significant potent antimicrobial and antioxidant activities compared to parent ligands employed for complexation. Supplemental materials are available for this article. Go to the publishers online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.