A series of monomers were prepared by reacting (meth)acryloyl chloride with 2,4-dihydroxybenzophenone, 2,4-dihydroxybenzaldehyde, and 2,4-dihydroxyacetophenone, respectively. The monomers were polymerized in dimethylformamide (DMF) at 70°C using benzoyl peroxide as an initiator. Polymer-metal complexes were obtained from DMF solutions of polymers with an aqueous solution of metal ions. The polymers and polymer-metal complexes were characterized by elemental analysis and spectral studies. The IR spectra of these complexes suggest that the metals are coordinated through the oxygen of the carbonyl group and the oxygen of the phenolic-OH group. The electronic spectra, electron paramagnetic resonance (EPR) spectra, and magnetic moments of polychelates showed an octahedral and square planar structure for Ni(II) and Cu(II) complexes, respectively. X-ray diffraction studies revealed that polychelates are highly crystalline. The thermal and electrical properties, catalytic activity, and structure-property relationships are discussed.
A novel polymeric Schiff base was synthesized by the reaction of a Schiff base from 2,4-dihydroxy benzaldehyde and aniline with acryloyl chloride and was polymerized in methyl ethyl ketone at 70°C with benzoyl peroxide as a free-radical initiator. Polychelates were obtained in an alkaline solution of poly(2-hydroxy-4-acryloyloxy-N-phenylbenzylidine) with aqueous solutions of metal ions such as Cu(II), Ni(II), Co(II), Ca(II), Cd(II), Mn(II), and Zn(II). The polymeric Schiff base and polychelates were characterized with elemental analysis and spectral studies. The elemental analysis of the polychelates suggested that the metal-to-ligand ratio was 1:2. The IR spectral data of the polychelates indicated that the metals were coordinated through the nitrogen and oxygen of the phenolic OOH group. Diffuse reflectance spectra, electron paramagnetic resonance, and magnetic moment studies revealed that the polychelates of the Cu(II) complex were squareplanar, those of the Ni(II), Mn(II), and Co(II) complexes were octahedral, and those of the Ca(II), Cd(II), and Zn(II) complexes were tetrahedral. X-ray diffraction studies revealed that the polychelates were highly crystalline. The thermal properties of the Schiff base and polychelates were also examined.
Articles you may be interested inThermal effect on magnetic parameters of high-coercivity cobalt ferrite J. Appl. Phys. 116, 033901 (2014); 10.1063/1.4890033Structural and ambient/sub-ambient temperature magnetic properties of Er-substituted cobalt-ferrites synthesized by sol-gel assisted auto-combustion method Variations in conductivity with particle size have been observed in cobalt ferrite, when synthesized by solgel auto-combustion method. Impedance analysis reveals metallic and semiconducting behavior at room temperature for a particle size of 6 nm and 52 nm, respectively. Upon thermal activation, metallic to semiconducting phase transition has been observed as a function of particle size and vice-versa. Grainboundary Resistance (R gb ), increased drastically with particle size (19 MX for 6 nm and 259 MX for 52 nm) at room temperature. AC conductivity and dielectric constants exhibit similar metallic to semiconducting phase transition at 6 nm and semiconducting behavior at 52 nm with temperature in the selected frequencies. Enhanced magnetic moment with an increase in the grain size along with decreased coercivity (1444 G to 1146 G) reveals transition from single domain to multi-domain. Increased inter-particle interaction is responsible for metallicity at the nano level and on the contrary semiconductivity is attributed to bulk. V C 2013 AIP Publishing LLC. [http://dx.
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