Narayan S. Bhave

Magnetic and spectral properties of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Pd(II) chelates of 2′-hydroxy-3′-bromo-4-methoxy-5′-methylchalkone oxime (HBMMCO)

Abstract A number of chelates of the transition metal ions Fe2+, Fe3+, Co2+, Ni2+, Cu2+ and Pd2+ with 2′-hydroxy - 3′ - bromo - 4 - methoxy - 5′ - methylchalkone oxime (HBMMCO) have been synthesised. Attempts have been made to assign their probable structures on the basis of elemental analysis, molar conductance, thermal analysis, absorption and reflectance spectra, IR spectra and magnetic data. The magnetic susceptibility of the Co(II) chelate follows the Curie-Weiss law and the observed temperature dependance is in favour of an octahedral configuration. The Ni(II) chelate exhibits a 6-coordinate octahedral structure, whilst distorted octahedral geometry is suggested for the Cu(II) chelate. The Fe(II) and Fe(III) chelates have high spin octahedral configurations and the dimagnetic behaviour of the Pd(II) complex indicates a square planer configuration.

Microwave Assisted Synthesis and Antimicrobial Study of Schiff Base Vanadium(IV) Complexes of Phenyl Esters of Amino Acids

Schiff base vanadium(IV) complexes of phenyl esters of the two acidic amino acids, i.e., aspartic and glutamic acid, were synthesized. The phenyl esters of these amino acids were synthesized by conventional method whereas the Schiff base vanadium(IV) complexes were synthesized using microwave irradiation. The complexes were characterized by spectroscopic tools such as IR, 1 H NMR, mass (ES), ESR, and UV visible spectroscopy. All the complexes were studied for antibacterial and antifungal activity and found to be moderately active.

Kinetics Study of Thermal Degradation of Resin Derived from Salicylaldehyde, Ethylenediamine and Formaldehyde

The present paper reports the synthesis and kinetics of thermal degradation studies of resin salicylicldehyde -ethylenediamine -formaldehyde (SdEDF) derived by the condensation of salicylicldehyde and ethylenediamine with formaldehyde in the presence of catalyst hydrochloric acid in 1:1:2 molar proportions of reactants. Detailed thermal degradation studies of the SdEDF resin has been carried out to ascertain its thermal stability. Thermal degradation curve has been discussed in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change, and apparent energy change. Freeman - Carroll and Sharp- Wentworth methods have been applied for the calculation of kinetic parameters while the data from the Freeman - Carroll methods have been used to determine various thermodynamic parameters.

Synthesis, Characterization and Thermal Degradation Study of Terpolymer-derived from p-Hydroxybenzoic Acid, Diaminonaphthelein with Formaldehyde

Resin pHDNF has been synthesized by the condensation of p-hydroxybenzoic acid and diaminonaphthelein with formaldehyde in the presence of catalyst hydrochloric acid in 1 : 1 : 2 molar proportions of reactants. The purity of newly synthesized terpolymer has been tested and confirmed by the thin layer chromatography (TLC) technique. Detailed thermal degradation studies of the pHDNF resin have been carried out to ascertain its thermal stability. The thermal degradation curve was examined in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change and apparent energy change. The Freeman—Carroll and Sharp—Wentworth methods were applied for the calculation of kinetic parameters and the data from the Freeman—Carroll method was been used to determine various thermodynamic parameters. The terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and UV-visible spectral studies. The number-average molecular weight of the resin was determined by non-aqueous conductometric titration.

Synthesis of resin I: salicylic acid, hexamethylene diamine and formaldehyde and its ion-exchange properties

Abstract The terpolymer resin salicylic acid-hexamethylenediamine-formaldehyde (SHMF) was synthesized by the condensation of salicylic acid and hexamethylenediamine with formaldehyde in the presence of a hydrochloric acid catalyst. The number average molecular weight of the resin was determined by non-aqueous conductometric titration. Terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and UV- Visible spectral studies. Chelation ion exchange properties have also been studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ions employing a batch equilibrium method. It was employed to study the selectivity of metal ion uptake involving the measurements of distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over wide pH range and in the media of various ionic strengths. The terpolymer showed a higher selectivity for Fe3+, Cu2+ and Ni 2+ions than for Co2+, Zn2+, Cd2+, and Pb2+ ions.

Microwave-assisted aqueous phase synthesis and single crystal study of oxovanadium(IV) (2-hydroxybenzylideneamino) acetate

Single crystal of oxovanadium(IV) (2-hydroxybenzylideneamino) acetate was synthesized by template method in aqueous phase using microwaves as the source of energy. A fine crystalline complex was obtained in high yield within a few minutes. All bond distances and angles were observed to study the effect of bonding of vanadium and distortion from normal. Other spectroscopic data are also reported.

Separation of Copper(II), Nickel(II), Palladium(II), and Cobalt(II) Chelates with 4-S-Benzyl-l-p-Cl-phenyl-5-phenyl-2,4-isodithiobiuret (BPPTB) from Their Binary Mixture by Adsorption Thin-Layer Chromatography

Abstract In the present work a suitable solvent system for the separation of Cu(II), Ni(II), Co(II), and Pd(II) as their chelates with 4-S-benzyl-1-p-Cl-phenyl-5-phenyl-2,4-isodithiobiuret (BPPTB) from their binary mixtures has been suggested. The most applicable solvent system has been found to be benzene-cyclohexane (3: 1). The best separation is achieved within 15 min. RF values of Ni-(BPPTB)2 and Co-(BPPTB)2 decrease with time. The substitution of benzene in a benzene–cyclohexane (1:1) solvent mixture by toluene decreases the RF value of metal chelates. Cu-(BPPTB)2 and Pd-(BPPTB)2 chelates do not migrate even with an increase in temperature. The RF value of Ni(BPPTB)2 chelate increases with temperature, whereas the RF value of Co-(BPPTB)2 remains practically constant.

Microwave Assisted Synthesis and Antioxidant Activity of Vanadium(IV) Complexes of Amino Acid Schiff Bases

Synthesis of some amino acid Schiff base complexes of vanadium(IV) was done using microwave mode of synthesis and aqueous/semiaqueous medium as solvent. Complexes were characterized by using common analytical and spectroscopic tools such as IR, 1H NMR, EI Mass, ESR, and magnetic susceptibility measurements. Single-crystal X-ray analysis of one of the complexes was carried out. Antioxidant activity of the complexes was studied using the DPPH scavenging method. The present work attempts to establish a possible structure and antioxidant activity correlation of the synthesized complexes. Some of the complexes show comparable activity to that of the standard reference (i.e., ascorbic acid).

Ion exchange study of some new biphenol–thiourea–formaldehyde terpolymer resins

Abstract Terpolymer resins, synthesized by reacting 2,2′-dihydroxybiphenyl with thiourea and formaldehyde in presence of HCl as catalyst, proved to be selective chelating ion-exchange resins for certain metal ions. Chelating ion-exchange properties of these terpolymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ ions. A batch equilibrium method has been employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The terpolymer showed higher selectivity for Fe3+, Cu2+ and Ni2+ ions than for Co2+, Zn2+, Cd2+ and Pb2+ ions.