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 53A

NUMBER 1

JANUARY 2014

 

CONTENTS

 

 

9

 

In silico architecturing of novel hetero-aromatic bicyclic copolymers using particle swarm optimization algorithm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Priyanka Thakral, Vinita Kapoor &
A K Bakhshi
*

 

 

 

 

 

 

 

17

 

Intramolecular proton transfer of 2-hydroxy-1-naphthaldehyde semicarbazone and thiosemicarbazone in ground and lowest excited singlet states:
A comparative experimental and computational study

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Debosreeta Bose & Nitin Chattopadhyay*

 

 

 

Intramolecular proton transfer of 2HNS and 2HNT takes place in the lowest excited singlet state, but not in the ground state.

 

 

 

 

 

27

 

Simultaneous reductive azo cleavage and nucleophilic addition of pyridyl imide to coordinated CO in a ruthenium complex. Isolation and characterization of new carbamoyl complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ipsita Chatterjee, Pradip Ghosh, Harashit Datta & Sreebrata Goswami*

 

 

 

An unusual Ru(0) mediated transformation involving in situ generated pyridylamide dianion and coordinated CO is described. The reference chemical transformation is followed by isolation and complete characterization of the ruthenium carbamoyl complexes.

 

 

 

 

 

 

 

 

34

 

Organoselenium compounds based on substituted acetanilides: Synthesis, characterization and antioxidant activity

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Prasad P Phadnis, Ananda S Hodage,
K I Priyadarsini & Vimal K Jain
*

 

 

Organoselenium compounds comprising substituted acetanilides are synthesized and evaluated for their antioxidant activities. The selenide analogous to paracetamol, (p-HOC6H4NHCOCH2)2Se, exhibits the highest antioxidant activity.

 

 

 

 

 

 

Notes

 

41

 

Catalysis of TBHP oxidation of styrene and diphenylmethane by a supported cobalt(III)-oxo cluster

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Purabi Sarmah & Birinchi K Das*

 

 

 

A cobalt(III) complex, supported on chemically modified mesoporous silica, efficiently catalyzes the TBHP oxidation of styrene as well as diphenylmethane.

 

 

 

 

 

 

 

 

46

 

pH-driven structure modulations in cobalt(II) coordination polymers constructed from
2,2
-bipyridine-5,5-dicarboxylic acid

 

 

 

 

 

 

 

 

 

 

Dibyendu Bhattacharya

 

 

 

 

 

 

 

 

52

 

Effect of secondary growth conditions on orientation and thickness of TS-1 membranes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Xiaodong Wang, Shaoni Li, Jing Yan, Xiaoyan Chen & Wei Huang*

 

 

 

 

 

57

 

Electrocatalytic oxidation of ascorbic acid by immobilized silver nanoparticles on self-assembled
L-cysteine monolayer modified gold electrode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Koushik Barman & Sk Jasimuddin*

 

 

 

Silver nanoparticles embedded Au/L-cysteine self-assembled monolayer electrode selectively determines ascorbic acid in presence of physiologically common interferents and has excellent detection limits of the order of 210-12 M.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

62

 

On the primary yield of radical products of anodic contact glow discharge electrolysis

 

 

 

 

 

 

Yamini Srivastava, Shilpi Jaiswal, Om Prakash Singh & Susanta K Sen Gupta*

 

 

 

Scavenging effects of Fe2+ on OH and H2O2 generated by anodic contact glow discharge electrolysis in acidic media are investigated. In the competing reactions of OH with different species in a Fe2+ containing system, the primary yield of for OH and H in the liquid phase reaction zone of anodic CGDE is found to be 11 mol(mol electron)-1 each. A comparison with the radiolytic yield of radicals suggests that the average energy of gaseous H2O+ ions bombarding the liquid H2O molecules and producing the radicals is substantially above 100 eV.

 

 

 

 

 

 

66

 

Guide to Authors

 

 

 

 

 

Authors for correspondence are indicated by (*)

 

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 9-16

 

 

In silico architecturing of novel hetero-aromatic bicyclic copolymers using
particle swarm optimization algorithm

Priyanka Thakrala, Vinita Kapoora & A K Bakhshia, b,*

aDepartment of Chemistry, University of Delhi, Delhi 110 007, India

bUP Rajarshi Tandon Open University, Shantipuram (Sector F), Phaphamau, Allahabad 211 013, India

Email: akbakhshi2000@yahoo.com

Received 3 July 2013; revised and accepted 6 December 2013

Using the ab initio Hartree Fock crystal orbital band structure results of the homopolymers, viz., polypyrrolo[3,4-C]pyrrole, polythieno[3,4-C]thiophene and polyfurano[3,4-C]furan, the electronic properties of their novel binary and ternary copolymers have been investigated using particle swarm optimization algorithm in combination with simple negative factor counting and inverse iteration method. The in silico architecturing of each copolymer has efficiently returned optimal composition corresponding to the lowest band gap and maximum delocalized configuration. The nature of the hetero-atom is found to predominantly influence the electronic properties of the copolymers. Moreover, the component with lowest ionization potential is found to be present maximally in the optimum solutions of the respective copolymers. The fused bicyclic copolymers are predicted to be better intrinsic conductors than their constituent homopolymers due to the enhanced delocalization and quinoidal character in these systems.

Keywords: Theoretical chemistry, Electrically conducting polymers, Conducting polymers, Electronic properties, Band gap, Particle swarm optimization, Copolymers, Bicyclic copolymers, Heteroaromatic copolymers

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 17-26

 

 

Intramolecular proton transfer of 2-hydroxy-1-naphthaldehyde semicarbazone and thiosemicarbazone in ground and lowest excited
singlet states: A comparative experimental and computational study

Debosreeta Bose & Nitin Chattopadhyay*

Department of Chemistry, Jadavpur University, Kolkata 700 032, India

Email: nitin.chattopadhyay@yahoo.com

Received 4 October 2013; revised and accepted 23 December 2013

Photophysics of 2-hydroxy-1-naphthaldehyde semicarbazone (2HNS) and the corresponding thiosemicarbazone (2HNT) are explored in n-heptane and methanol as solvents, focusing on the intramolecular proton transfer (IPT) in the ground (S0) and the first excited singlet (S1) states using absorption, steady state and time-resolved fluorometric techniques. The feasibility of the IPT process in the two molecular systems has also been compared. Experiments confirm that for both the compounds IPT takes place in the lowest excited singlet state (S1), but not in the ground state (S0). Ab-initio quantum chemical calculations provide support to the experimental findings. Simulated potential energy curves (PEC) in the two electronic states imply that the IPT process is endothermic in the S0 state but becomes exothermic in the S1 state for both the probes. PECs also reveal that compared to the ground state the activation barrier for the IPT process is reduced appreciably in the S1 state. The IPT process, thus, becomes feasible both thermodynamically and kinetically in the S1 state but not in the S0 state. The experiments and calculations, however, reveal that the excited state intramolecular proton transfer process is relatively more viable for 2HNS compared to 2HNT. Further, the work demonstrates that any of the suitably chosen structural parameters leading to the unique transition state and yielding the same values of the reaction parameters can be taken as the reaction coordinate to follow the progress of the intramolecular prototropic process.

Keywords: Intramolecular proton transfer, Tautomers, Fluorescence, Potential energy curves

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 2733

 

 

Simultaneous reductive azo cleavage and nucleophilic addition of pyridyl imide to coordinated CO in a ruthenium complex. Isolation and
characterization of new carbamoyl complexes

Ipsita Chatterjee, Pradip Ghosh, Harashit Datta & Sreebrata Goswami*

Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India

Email: icsg@iacs.res.in

Received 25 October 2013; revised and accepted 23 December 2013

Reactions of Ru3(CO)12 with 2-(arylazo)pyridines (L1a-c) in boiling toluene afford the violet complexes,
RuII(L1a-c)(L2)(CO)Cl (1a-c, [L2] = N-(pyridin-2-yl)formamide). This reaction exemplifies an unusual transformation wherein the anionic bidentate ligand [L2] is formed by the nucleophilic attack of phenyl imide fragment (formed in situ by the rupture of -N=N-) on coordinated carbon monoxide. The Ru-carbamoyl complexes are characterized by X-ray crystallographic structure analysis of one of a representative complex (1b), nuclear magnetic resonance spectra, cyclic voltammetry, ultraviolet-visible spectroscopy, electron paramagnetic resonance spectroscopy, and density functional theory. The complexes display one reversible cathodic response near -0.60 V along with an irreversible anodic response near 1.40 V. The response at cathodic potential is due to reduction of the coordinated azo-function while that in anodic potential is presumably due to oxidation of RuII-center. The reversible reductive process is characterized by EPR spectroscopy. Density functional theory calculations have been employed to confirm structural features and to support their spectral and redox properties.

Keywords: Coordination chemistry, Reductive azo cleavage, Nucleophilic addition, X-ray structure,
Redox properties, Ruthenium

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 34-40

 

 

Organoselenium compounds based on substituted acetanilides:
Synthesis, characterization and antioxidant activity

Prasad P Phadnisa, Ananda S Hodagea, K I Priyadarsinib & Vimal K Jaina, *

aChemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India

bRadiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India

Email: jainvk@barc.gov.in

Received 30 September 2013; received and accepted 19 December 2013

A series of organoselenium compounds based on substituted acetanilides of compositions, Se{(CH2)nCONHC6H4X}2 (n = 1, 2) and (SeCH2CH2CONHC6H4X)2 (X = OH/ NH2) have been synthesized and characterized by microanalyses, IR, NMR (1H, 13C{1H}, 77Se{1H}) spectroscopy and mass spectrometry. Antioxidant activity of these compounds has been evaluated against DPPH radicals in vitro. Some of these compounds exhibit better inhibition of DPPH radicals than standard BHT. The selenide, analogous to paracetamol, (p-HOC6H4NHCOCH2)2Se, exhibits the highest antioxidant capacity in a given series.

Keywords: Coordination chemistry, Organoselenium compounds, Acetanilides, Antioxidant activity, Selenium

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 41-45

 

 

Catalysis of TBHP oxidation of styrene and diphenylmethane by a supported cobalt(III)-oxo cluster

Purabi Sarmaha & Birinchi K Das*

Department of Chemistry, Gauhati University Guwahati 781 014, Assam, India

Email: das_bk@rediffmail.com (BKD)/
purabi_chem@yahoo.co.in (PS)

Received 29 August 2013; revised and accepted 18 December 2013

The supported catalyst produced by immobilising the cobalt(III)-oxo cluster Co4O4(O2CMe)4(py)4 on chemically modified mesoporous silica shows very good activity in the tert-butyl hydroperoxide oxidation of styrene and diphenylmethane. While complete conversion of styrene takes place to yield styrene epoxide at moderate selectivity, diphenylmethane is completely converted to obtain benzophenone at excellent selectivity.

Keywords: Catalysts, Supported Catalysts, Immobilised catalyst, Cubane clusters, Cobalt-oxo clusters,
Mesoporous silica, Oxidation, Epoxidation, Diphenylmethane, Styrene

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 46-51

 

 

pH-driven structure modulations in cobalt(II) coordination polymers
constructed from 2,2
-bipyridine-5,5-dicarboxylic acid

Dibyendu Bhattacharya

Chemistry and Biomimetics Group, CSIR-Central Mechanical Engineering Research Institute,
Mahatma Gandhi Avenue, Durgapur 713 209, India

Email: drdibyendubhattacharya@gmail.com

Received 19 March 2013; revised and accepted 10 December 2013

Two new Co(II) coordination polymers, viz., [{Co(bpdc)(H2O)}CH3OH] (1) and [Co(bpdc)(H2O)3] (2) (H2bpdc = 2,2-bipyridine-5,5-dicarboxylic acid) are obtained in quantitative yields from the reaction of CoCl26H2O and H2bpdc in a water-rich environment in the presence of KOH at ambient temperature. While at pH = 5, compound (2) showing a 1D zigzag chain is obtained, at pH = 2, compound (1) is obtained which has a 2D rhombic grid-work from two sets of parallel {Co(H2O)(bpdc)} chains which cross at the Co(II) sites at an angle of 70 with (4,4)-topology. Hence, the pH of the solution is found to be an important factor in determining the coordination mode and dimensionality in the self-assembly of Co(II) and H2bpdc under mild conditions.

Keywords: Coordination chemistry, Coordination polymer, Carboxylate ligands, Cobalt, Crystal engineering,
Self-assembly

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 52-56

 

 

Effect of secondary growth conditions on orientation and
thickness of TS-1 membranes

Xiaodong Wang, Shaoni Li, Jing Yan, Xiaoyan Chen & Wei Huang*

Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province,
Taiyuan University of Technolog
y, Taiyuan, 030024, PR China

Email: huangwei@tyut.edu.cn

Received 11 March 2013; revised and accepted 4 December 2013

The b-oriented TS-1 membranes have been synthesized by controlling alkalinity and hydrothermal reaction time in the secondary growth process. The results of SEM and XRD show that in the 1TEOS: 0.008TBOT: xTPAOH: 77H2O system, with higher alkalinity (x = 0.21), the b-orientation of the seed layer is maintained only at short reaction time (12 h), and the membranes formed are asymmetric. With moderate alkalinity (x = 0.13) and lower alkalinity (x = 0.09), a longer time period (24 and 36 h is needed to prepare a compact b-oriented membrane; this membrane is symmetric. On prolonging the hydrothermal reaction time, the orientation of the seed layer is lost and the membranes are a&b oriented. With the alkalinity x = 0.13 and hydrothermal reaction time of 24 h, the membrane is at the highest quality, and is compact, symmetric, b-oriented and ca. 3 μm thick.

Keywords: Membranes, Zeolite membranes, MFI membranes, Hydrothermal synthesis, Channel orientation,
B-oriented membranes, Membranes orientation, Secondary growth method

 

 

Indian Journal of Chemistry

Vol. 53A, January 2014, pp. 57-61

 

 

Electrocatalytic oxidation of ascorbic acid by immobilized silver nanoparticles on self-assembled L-cysteine monolayer modified
gold electrode

Koushik Barman & Sk Jasimuddin*

Department of Chemistry, Assam University Silchar 788 011, Assam, India

Email: j.seikh@gmail.com

Received 23 April 2013; revised and accepted 26 December 2013

The electrocatalytic oxidation of ascorbic acid in phosphate buffer solution (pH 7.0) by immobilized silver nanoparticles (Ag@CTAB) on L-cysteine modified gold electrode is reported. The modified electrode has been characterized electrochemically using redox couple [Fe(CN)6]3-/4-. The electrocatalytic activity of the prepared electrodes is studied using cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical measurements show that the modified electrode (Au/L-cysteine/AgNPs) is highly active towards ascorbic acid oxidation. The oxidation peak of ascorbic acid at the Au/L-cysteine/AgNPs electrode is highly stable upon repeated potential cycling. The oxidation current of ascorbic acid increases upon each increment (0.05−0.35 mM) in differential pulse voltammetry experiments. The oxidation current shows a linear relationship with the concentration of ascorbic acid with a correlation coefficient of 0.996. The detection limit of ascorbic acid was found to be 210-12 M. Common physiological interferents such as glucose, tartaric acid, citric acid and cysteine do not show any interference within the detection limit of ascorbic acid. The silver nanoparticles modified gold electrode has been used to determine the amount of ascorbic acid present in fruit and vegetable juices.

Keywords: Electrocatalytic oxidation, Ascorbic acid, Silver nanoparticles, L-Cysteine, Self-assembled monolayer,
Gold electrode

 

 

Indian Journal of Chemistry

Vol 53A, January 2014, pp. 62-65

 

 

On the primary yield of radical products of anodic contact glow
discharge electrolysis

Yamini Srivastava, Shilpi Jaiswal, Om Prakash Singh & Susanta K Sen Gupta*

Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India

Email: sksbhuchem@yahoo.co.in

Received 9 July 2013; revised and accepted 23 December 2014

Scavenging effects of Fe2+ on OH and H2O2 generated by anodic contact glow discharge electrolysis in acidic media have been investigated. Analysis of a kinetic scheme involving competing reactions of OH with different species in a Fe2+ containing system leads to a primary yield of 11 mol (mol electron)-1 each for OH and H each in the liquid phase reaction zone of anodic CGDE. This value agrees well with the yields reported in previous studies involving H and other OH scavengers and thus may be accepted as a reliable measure of the primary radical yield of anodic CGDE. A comparison with the radiolytic yield of radicals suggests that the average energy of gaseous H2O+ ions bombarding the liquid H2O molecules and producing the radicals is substantially above 100 eV.

Keywords: Contact glow discharge electrolysis, Ferrous ion scavenger, Non-faradaic yields, Primary radical yield