NOPR Collection:

Kinetics and mechanism of oxidation of aliphatic and aromatic alcohols by in situ generated bromine in reaction between oxone and bromide ion

2016-02-15T17:50:35Z

Title: Kinetics and mechanism of oxidation of aliphatic and aromatic alcohols by in situ generated bromine in reaction between oxone and bromide ion Authors: Thombare, Malharrao R; Gokavi, Gavisiddappa S Abstract: Oxidation of aliphatic and aromatic alcohols by oxone catalyzed by bromide ions has been studied in acidic medium, to avoid formation of alkoxide. Since no prior protonation equilibrium is involved, the rate of the reaction is independent of pH. The reaction is initiated by the oxidation of bromide to bromine, which abstracts a hydride ion from the alcohol in a rate determining step to form R₁R₂COH⁺ cation. This cation loses a proton to give the corresponding carbonyl compound in a fast step. A mechanism for the bromide ion mediated oxidation is proposed and the rate law is derived based on the mechanism. Effect of relative permittivity, ionic strength and temperature is also studied; these effects also support the proposed mechanism. Page(s): 182-186

Oxygen reduction reaction of manganese oxide/graphene oxide nanocomposite

2016-02-01T00:00:00Z

Title: Oxygen reduction reaction of manganese oxide/graphene oxide nanocomposite Authors: Pravinkumar, K; Balaji, S; Manichandran, T; Anandakumar, M; Kumaraguruparan, G Abstract: MnO₂/graphene oxide composite coating has been prepared by electrochemical anodic deposition method. Optimization of current density and deposition efficiency is reported. The formation of α-MnO₂/graphene oxide nanocomposite is elucidated through X ray diffraction and infrared reflection measurements. Morphological studies reveal the increase in porosity and exfoliation of graphene oxide by MnO₂ particles. The extent of oxygen reduction reaction occurring at the surface of MnO₂/graphene oxide composite coating have been analyzed by cyclic voltammetry and electrochemical impedance spectroscopy in aqueous 1 M Li₂SO₄ solution. The composite coating is observed to possess better catalytic properties towards oxygen reduction. Page(s): 177-181

Tetraaquabis(4-methoxyphenylacetato-O') magnesium(II) dihydrate and catena-poly[[(diaqua)manganese(II)]- bis(μ₂-4-methoxyphenylacetato-O,O')]: A monomeric and a two-dimensional coordination polymer based on 4-methoxyphenylacetic acid

2016-02-15T17:43:12Z

Title: Tetraaquabis(4-methoxyphenylacetato-O') magnesium(II) dihydrate and catena-poly[[(diaqua)manganese(II)]- bis(μ₂-4-methoxyphenylacetato-O,O')]: A monomeric and a two-dimensional coordination polymer based on 4-methoxyphenylacetic acid Authors: Dhavskar, Kiran T; Srinivasan, Bikshandarkoil R Abstract: The synthesis and characterization of tetraaquabis(4-methoxyphenylacetato-O')magnesium(II) dihydrate (1) and catena-poly[[(diaqua)manganese(II)]bis(μ₂-4-methoxyphenylacetato-O,O')] (2) based on 4-methoxyphenylacetic acid (4-mpaH) ligand is reported. In 1, the unique 4-mpa functions as a monodentate ligand for Mg(II) situated on an inversion centre, resulting in a monomeric Mg(II) complex. The Mn(II) in 2 is also located on an inversion centre and the μ₂-bridging bidentate coordination mode of the unique 4-mpa ligand results in the formation of a two-dimensional manganese coordination polymer. Page(s): 170-176

Micellar parameters and thermodynamics of interaction of fluoroquinolone drugs with cetyldimethylethylammonium bromide

2016-02-15T17:41:10Z

Title: Micellar parameters and thermodynamics of interaction of fluoroquinolone drugs with cetyldimethylethylammonium bromide Authors: Ahsan, Sk. Md. Ali; Hossain, Mohammed Delwar; Hoque, Md. Anamul; Khan, Mohammed Abdullah Abstract: Interaction of fluoroquinolone antibiotic drugs, viz., ciprofloxacin hydrochloride, levofloxacin hemihydrate and lomefloxacin hydrochloride, with the cationic surfactant cetyldimethylethylammonium bromide (CDMEAB) has been studied by conductance measurements in water and in the presence of salts such as NaCl, Na₂SO₄ and Na₃PO₄·12H₂Oover the temperature range of 298.15–318.15 K. Two critical micelle concentrations (c*) are obtained for drug-CDMEAB systems in all the cases. The change of c* values of CDMEAB due to the addition of the drugs is indicative of the interaction between drugs and CDMEAB. Favourable micellization of drug-CDMEAB systems is observed in the presence of salts. The ∆G⁰_m values were negative in all the cases. The values of ∆H⁰_m and ∆S⁰_m reveal that the binding interactions between drug and CDMEAB in water are both electrostatic and hydrophobic in nature. The existence of linear correlation between ∆H⁰_m and ∆S⁰_m values is observed in all cases. Page(s): 160-169

NOPR Collection:

Kinetics and mechanism of oxidation of aliphatic and aromatic alcohols by in situ generated bromine in reaction between oxone and bromide ion

Oxygen reduction reaction of manganese oxide/graphene oxide nanocomposite

Tetraaquabis(4-methoxyphenylacetato-O') magnesium(II) dihydrate and catena-poly[[(diaqua)manganese(II)]- bis(μ2-4-methoxyphenylacetato-O,O')]: A monomeric and a two-dimensional coordination polymer based on 4-methoxyphenylacetic acid

Micellar parameters and thermodynamics of interaction of fluoroquinolone drugs with cetyldimethylethylammonium bromide

Tetraaquabis(4-methoxyphenylacetato-O') magnesium(II) dihydrate and catena-poly[[(diaqua)manganese(II)]- bis(μ₂-4-methoxyphenylacetato-O,O')]: A monomeric and a two-dimensional coordination polymer based on 4-methoxyphenylacetic acid