Indian Journal of Chemistry

Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical

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CODEN: ICACEC; ISSN: 0376-4710 (Print), 0975-0975 (Online)

 

 

 

 

VOLUME 55A

NUMBER 2

FEBRUARY 2016

 

CONTENTS

 

 

137

 

Synthesis, crystal structure, redox property and theoretical studies of a pyrrole containing cobalt(III) Schiff base compound

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Anangamohan Panja* & Tarun Kanti Mandal

 

 

 

A mononuclear cobalt(III) complex with a pentadentate Schiff base ligand derived from the condensation of N-(3-aminopropyl)-propane-1,3-diamine with pyrrole-2-aldehyde has been synthesised. X-ray crystallography reveals that the geometry of cobalt(III) ion is a distorted octahedron in which the triamine part of the pentadentate ligand occupies the meridional positions, while two pyrrole nitrogen atoms are in cis dispositions.

 

molecule.jpg

 

 

 

145

 

Synthesis of zinc porphyrins and effect of peripheral substituents on the coordination reaction

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Shujun Wang*, Yuling Peng, Chenggen Zhang, Yongbing Li & Chao Liu

 

 

 

Free-base porphyrins modified with Boc-d-threonine and their zinc porphyrins have been synthesized. The reaction is spontaneous, with coordinated bonds formed between zinc porphyrins and imidazole derivatives. The ability to form complexes is related to the peripheral substituents in zinc porphyrins and the structure of imidazole derivatives. The zinc porphyrin synthesized with 4-chlorobenzaldehyde and
N-methylimidazole shows the highest association constant.

 

Graphical abstract.tif

 

 

 

153

 

Humic acid-induced synthesis of hierarchical basic copper carbonate/AlOOH microspheres and its enhanced catalytic activity for 4-nitrophenol reduction

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wenjin Zhang, Zhengbin Tian, Lijian Chen &
Shiyun Ai
*

 

 

 

The urchin-like HA-BBC/AlOOH (0.62 min-1) shows better performance than pure BBC/AlOOH microspheres with flower-like structure (0.39 min-1) for reduction of 4-nitrophenol to
4-aminophenol with excess NaBH4 as a model reaction. Also, addition of humic acid during synthesis of the catalysts greatly enhances the catalytic efficiency.

 

 

 

 

 

160

 

Micellar parameters and thermodynamics of interaction of fluoroquinolone drugs with cetyldimethylethyl-ammonium bromide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sk. Md. Ali Ahsan, Mohammed Delwar Hossain,
Md. Anamul Hoque* & Mohammed Abdullah Khan

 

 

 

Interaction of fluoroquinolone antibiotic drugs, viz., ciprofloxacin hydrochloride, levofloxacin hemihydrate and lomefloxacin hydrochloride, with the cationic surfactant, cetyldimethylethyl-ammonium bromide, is studied by conductance measurements in water and in the presence of salts such as NaCl, Na2SO4 and Na3PO4.12H2O over the temperature range of 298.15318.15 K. Addition of drug alters the micellization behaviour of the surfactant. Favourable micellization is observed in the presence
of salts
. Thermodynamic parameters reveal that drug-CDMEAB interactions are mainly hydrophobic and electrostatic in nature.

 

 

 

Notes

 

170

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

Kiran T Dhavskar & Bikshandarkoil R Srinivasan*

 

 

 

In tetraaquabis(4-methoxyphenylacetato-O')magnesium(II) dehydrate, the 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 catena-poly[[(diaqua)-manganese(II)]-bis(μ2-4-methoxy-phenylacetato-O,O')] is also located on an inversion centre and the
μ2-bridging bidentate coordination mode of the ligand results in formation of a two-dimensional Mn(II) coordination polymer.

GA10_CrystalPacking.BMP

 

 

 

177

 

Oxygen reduction reaction of manganese oxide/graphene oxide nanocomposite

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K Pravinkumar, S Balaji*, T Manichandran,
M Anandakumar & G Kumaraguruparan

 

 

 

MnO2/graphene oxide composite coating has been prepared by electrochemical anodic deposition method. Morphological studies reveal the increase in porosity and exfoliation of graphene oxide
by MnO2 particles.
The MnO2/GO composite coating has low
over-potential for oxygen reduction as compared to MnO2.

 

 

 

 

182

 

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

 

 

 

 

 

 

 

Malharrao R Thombare & Gavisiddappa S Gokavi*

 

 

 

 

 

Authors for correspondence are indicated by (*)

 

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Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 137-144

 

 

Synthesis, crystal structure, redox property and theoretical studies of
a pyrrole containing cobalt(III) Schiff base compound

Anangamohan Panjaa,* & Tarun Kanti Mandalb

a Postgraduate Department of Chemistry, Panskura Banamali College, Panskura RS, West Bengal 721 152, India

b Department of Biotechnology, Haldia Institute of Technology, Hatiberia, Haldia, West Bengal 721 657, India

Email: ampanja@yahoo.co.in

Received 10 June 2015; revised and accepted 1 February 2016

A new mononuclear cobalt(III) complex with a pentadentate Schiff base ligand derived from the condensation of N-(3-aminopropyl)-propane-1,3-diamine with pyrrole-2-aldehyde has been synthesized and structurally characterized by X-ray crystallography. Structural analysis shows that the geometry of cobalt(III) ion is a distorted octahedron in which triamine part of the pentadentate ligand occupies the meridional positions, while two pyrrole nitrogen atoms are in cis disposition. Despite the potentially interesting similarities of pyrrole-based ligands to porphyrin systems, the present complex is inactive towards the oxidation of
o-aminophenol, while analogous systems with pyridine containing ligands have proven to be efficient functional models for phenoxazinone synthase.
Although the electrospray ionization mass spectral study clearly indicates the formation of a complex-substrate aggregate, the inability towards oxidation of o-aminophenol by the present complex can be explained electrochemically, where strong electron donating ability of the deprotonated pyrrole moiety reduces the possibility of reduction of cobalt(III) to cobalt(II).

Keywords: Coordination chemistry, Schiff bases, Pyrrole ligands, Cobalt, X-ray crystal structures,
Density functional calculations, Cyclic voltammetry, Mass spectroscop

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 145-152

 

 

Synthesis of zinc porphyrins and effect of peripheral substituents
on the
coordination reaction

Shujun Wang*, Yuling Peng, Chenggen Zhang, Yongbing Li & Chao Liu

College of Chemistry and Materials Science, Langfang Teachers University, Langfang 065000, China

Email: d022036@mail.nankai.edu.cn

Received 28 August 2015; revised and accepted 22 January 2016

Three free-base porphyrins, modified with Boc-d-threonine and their zinc porphyrins have been synthesized using benzaldehyde, 4-chlorobenzaldehyde, and 4-methoxybenzaldehyde. The effects of peripheral substituents on the coordination reactions between zinc porphyrins and imidazole derivatives have been studied by UV-visible spectroscopy, fluorescence spectrometry, and theoretical calculations. The results show that the coordination reaction forms a Zn-N bond between zinc porphyrins involving different peripheral substituents and imidazole derivatives. The association coordination constants decrease (N-MeIm > Im) due to the change in enthalpy; the zinc porphyrin synthesized using 4-chlorobenzaldehyde and N-methylimidazole shows the largest association constant. Fluorescent quenching is observed during the coordination process with the zinc porphyrin synthesized using 4-methoxybenzaldehyde and N-methylimidazole showing the largest Stern-Volmer quenching rate constant. In addition, theoretical calculations have been used to investigate essential characteristics of the reaction, charges, bond lengths, and bond energies for each system.

Keywords: Coordination chemistry, Theoretical chemistry, Porphyrins, Zinc porphyrins,
UV-visible spectroscopy, Fluorescence quenching

 

 

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 153-159

 

 

Humic acid-induced synthesis of hierarchical basic copper carbonate/AlOOH microspheres and its enhanced catalytic activity
for 4-nitrophenol reduction

Wenjin Zhang, Zhengbin Tian, Lijian Chen & Shiyun Ai*

College of Chemistry and Material Science, Shandong Agricultural University, Taian, 271018, PR China

Email: ashy@sdau.edu.cn

Received 7 July 2015; revised and accepted 15 January 2016

One-pot synthesis of basic copper carbonate/AlOOH microspheres with hierarchical structure in the absence and presence of humic acid is presented. The synthesized microspheres are characterized by SEM, EDS, TEM, XRD, FT-IR and TGA data. The catalytic ability of these hierarchical structures has been evaluated with reduction of 4-nitrophenol to 4-aminophenol with excess amount of NaBH4 as a model reaction. The reduction is regarded as a pseudo first-order reaction and the activation energy calculated to from the Arrhenius plots. The urchin-like HA-BBC/AlOOH shows better catalytic performance than the pure BBC/AlOOH samples with flower-like structure.

Keywords: Catalysts, Reduction, Nitrophenol reduction, Microspheres, BCC/AlOOH microspheres,
Humic acid, Hierarchical structure

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 160-169

 

 

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

Sk. Md. Ali Ahsan, Mohammed Delwar Hossain, Md. Anamul Hoque* & Mohammed Abdullah Khan

Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh

Email: ahoque_ju@yahoo.com

Received 1 September 2015; revised and accepted 18 January 2016

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 Na3PO412H2O over the temperature range of 298.15318.15 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 ∆G0m values were negative in all the cases. The values of ∆H0m and ∆S0m reveal that the binding interactions between drug and CDMEAB in water are both electrostatic and hydrophobic in nature. The existence of linear correlation between ∆H0m and ∆S0m values is observed in all cases.

Keywords: Solution chemistry, Surfactants, Micellization, Drug-surfactant interactions,
Surfactant-drug interactions, Hydrophobic interactions, Thermodynamic parameters, Cetyldimethylethylammonium bromide, Fluoroquinolones

 

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 170-176

 

 

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

Kiran T Dhavskar & Bikshandarkoil R Srinivasan*

Department of Chemistry, Goa University, Goa 403 206, India

Email: srini@unigoa.ac.in

Received 2 November 2015; accepted 2 February 2016

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.

Keywords: Coordination polymer, Two-dimensional coordination polymers, Monodentate ligands,
Bridging bidentate ligands, Methoxyphenylacetic acid, Manganese, Magnesium

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 177-181

 

 

Oxygen reduction reaction of manganese oxide/graphene
oxide nanocomposite

K Pravinkumara, S Balajib, *, T Manichandranb, M Anandakumarb & G Kumaraguruparana

aDepartment of Mechanical Engineering, Thiagarajar College of Engineering, Madurai 625 015, Tamilnadu, India

bMaterials Technology Lab, Thiagarajar Advanced Research Centre, Thiagarajar College of Engineering,
Madurai 625 015, Tamilnadu, India

Email: sbalaji@tce.edu

Received 17 July 2015; revised and accepted 29 January 2016

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.

Keywords: Nanocomposites, Oxides, Graphene oxides, Oxygen reduction reaction, Manganese oxide

 

 

 

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 55A, February 2016, pp. 182-186

 

 

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

Malharrao R Thombare & Gavisiddappa S Gokavi*

Department of Chemistry, Shivaji University, Kolhapur 416004, Maharashtra, India

Email: gsgokavi@hotmail.com

Received 7 December 2015, revised and accepted 1 February 2016

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.

Keywords: Kinetics, Reaction mechanism, Oxidation, Oxone, Bromide ion, Alcohols, Aliphatic alcohols, Aromatic alcohols