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 5

MAY 2016

 

CONTENTS

 

 

529

 

DFT studies of intramolecular double proton transfer of 3,6-dihydro-3,6-diimino(siliane or pyridine)-
2,5-diamine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hasan Tahermansouri* & Lida Farhan

 

 

 

Intramolecular double proton transfer of 3,6-dihydro-3,6-diiminosiline-2,5-diamine (A) and 3,6-dihydro-3,6-diiminopyridine-2,5-diamine (B) at DFT (B3LYP) level of theory has been investigated. For both the compounds,  the process of proton transfer is through the stepwise mechanism (TS1), which itself includes two pathways, pathway (1) and pathway (2), involving the resonance forms from side of N-C-C-C-N and N-C-X-C-N atoms (X = Si-H or N), respectively. For compound (A) the process is through pathway (1), while for compound (B), both pathways (1) and (2) are almost similar to each other. In addition, aromaticity of the two compounds has been evaluated based on the nucleus independent chemical shift values to predict dominant resonance structures and the charge distributions in the ring.

 

 

 

 

537

 

Biogenic Ag-nanoparticles as heterogeneous catalyst for synthesis of 2-aryl benzimidazoles at room temperature

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Eramoni Saikia & Bolin Chetia*

 

 

 

Synthesis of silver nanoparticles by reduction of Ag+ ion by Syzygium jambos (L.) Alston leaves extract is reported. Spherical, nanometer-sized particles, with average particle size of 20 nm are formed. The Ag-nanoparticles efficiently catalyze the synthesis
of 2-substituted benzimidazoles by the reaction of aldehydes with o-phenylenediamine in DMSO at room temperature
.

 

 

 

 

544

 

Tuning the physicochemical properties of protic-aprotic ionic liquids upon reciprocal binary mixing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pankaj Bharmoria, Tushar J Trivedi, Naved I Malek* & Arvind Kumar*

 

 

 

The alterations in properties of protic/aprotic (2-hydroxyethyl-ammonium formate)/ 1-butyl-3-methylimidazolium methyl sulfate) ionic liquids, based on reciprocal binary mixing concept ([A][B][X][Y]) indicate a very high level of non-ideality in the mixtures which is required for improved solvent properties.

 

 

 

 

 

Notes

 

554

 

Vapour phase hydrogenation of aqueous levulinic acid to γ-valerolactone over CuZnAlO hydrotalcite

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V Swarna Jaya* & Medak Sudhakar

 

 

 

Vapour phase hydrogenation of levulinic acid to γ-valerolactone has been accomplished in aqueous phase over copper-zinc-aluminum hydrotalcite, prepared by co-precipitation method using nitrate salts as their precursors. The hydrotalcite system exhibits superior activity in the hydrogenation and cyclization of 10% aqueous solution of levulinic acid with >99% selectivity for γ-valerolactone at 275 oC under atmospheric pressure of hydrogen (flow rate of H2: 30 mL/min).

 

Graphical abstract.JPG

 

 

 

560

 

Hydrolytic cleavage of paraoxon and parathion by oximate and functionalized oximate ions: A comparative study

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hitesh K Dewangan, Neha Kandpal, Rekha Nagwanshi & Manmohan L Satnami*

 

 

 

The bimolecular reactions of paraoxon and parathion with oximate and functionalized oximate, 4-(hydroxyimino)methyl)-1-alkylpyridinium bromide ions (alkyl = C10H21 (4-C10PyOx-); alkyl = C12H25 (4-C12PyOx-)) have been investigated in aqueous and cationic micellar media of cetylpyridinium bromide, cetyltrimethylammonium bromide and cetyltetradecyltrimethylammonium bromide at pH 9.5 and 27 oC. Under the micellized condition, a 1.2×103 fold and 9.0×106 fold rate enhancement over the aqueous reaction of paraoxon
(ko = 7.5×10-8 s-1) and parathion (ko = 9.5×10-11) is observed.

 

 

 

 

566

 

Synthesis of heteroatom-doped ZnO nanoparticles as
an efficient visible light photocatalyst and its photoelectrochemical performance

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wenjie Wu, Xiaodan Zhu, Qiaoqiao Yin, Linxiang Tan, Xiaoxia Ke & Ru Qiao*

 

 

 

Zn1-xNixO exhibits better photocatalytic activity than pure ZnO which may be due to longer lifetime and higher separation efficiency of photogenerated charges as shown by the transient photocurrent response and EIS experiments. OH and h+ are primarily responsible for the enhanced photocatalytic performance of Rhodamine B.

 

 

 

 

571

 

Utilization of sodium montmorillonite clay for enhanced electrochemical sensing of amlodipine

 

 

 

 

 

A Mohamed Sikkander, C Vedhi & P Manisankar*

 

 

 

Nanosize surface of sodium montmorillonite has been prepared via sonication and deposited on glassy carbon electrodes for use as working electrode in a highly sensitive electrochemical biosensor for the detection of trace amounts of the calcium channel blocking drug, amlodipine. In alkali medium (pH 13.0), the sensor shows good response. The anodic peak current is linear with analyte concentration at optimum conditions; the detection limit has been determined to be 0.01 μg/mL.

 

 

 

Authors for correspondence are indicated by (*)

 

 

 

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Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 529-536

 

 

DFT studies of intramolecular double proton transfer of
3,6-dihydro-3,6-diimino(siliane or pyridine)-2,5-diamine

Hasan Tahermansouri* & Lida Farhan

Department of Chemistry, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran

Email: h.tahermansuri@iauamol.ac.ir/tahermansuri@yahoo.com

Received 12 November 2015; revised and accepted 26 April 2016

Intramolecular double proton transfer of 3,6-dihydro-3,6-diiminosiline-2,5-diamine (A) and 3,6-dihydro-
3,6-diiminopyridine-2,5-diamine (B) at DFT (B3LYP) level of theory has been investigated. Two mechanisms, stepwise (TS1) and concerted (TS2), are proposed for the process of proton transfer. The stepwise mechanism itself includes two pathways, the pathway (1) and pathway (2), which involve the resonance forms from side of N-C-C-C-N and N-C-X-C-N atoms (X = Si-H or N), respectively. These results show that for both the compounds the process of proton transfer is through the stepwise mechanism. The results indicate that in the case of compound (A) the process is through pathway (1), while for compound (B) the pathways (1) and (2) were almost similar to each other. In addition, aromaticity of the two compounds has been evaluated based on the nucleus independent chemical shift values to predict dominant resonance structures and the charge distributions in the ring.

Keywords: Theoretical chemistry, Density functional calculations, Proton transfer, Intramolecular proton transfer, Double proton transfer, Aromaticity

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 537-543

 

 

Biogenic Ag-nanoparticles as heterogeneous catalyst for synthesis of
2-aryl benzimidazoles at room temperature

Eramoni Saikia & Bolin Chetia*

Department of Chemistry, Dibrugarh University, Dibrugarh 786 004, Assam, India

Email: bolinchetia@dibru.ac.in

Received 26 May 2015; revised and accepted 27 April 2016

A green, straightforward and rapid method of synthesizing silver nanoparticles in an aqueous medium has been developed using Syzygium jambos (L.) Alston (Bogi Jamu) leaves extract and aqueous AgNO3 solution. The silver nanoparticles were characterized by UV–vis spectroscopy, transmission electron microscopy, X-ray diffraction and scanning electron microscopy. The results indicate the formation of spherical, nano-sized particles, with average particle size of 20 nm based on TEM analysis. The Ag-nanoparticles efficiently catalyze the synthesis of 2-substituted benzimidazoles by the reaction of aldehydes with o-phenylenediamine in DMSO at room temperature. Simple workup, mild reaction conditions, low cost, easy separation, and reusability of the catalyst are some advantages of this method.

Keywords: Biogenic synthesis, Catalysts, Heterogeneous catalysts, Nanoparticles, Silver nanoparticles, Benzimidazole

 

 

 

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 544-553

 

 

Tuning the physicochemical properties of protic-aprotic ionic
liquids upon reciprocal binary mixing

Pankaj Bharmoriaa, Tushar J Trivedia, Naved I Malekb, * & Arvind Kumara,c, *

aAcSIR, CSIR-Central Salt and Marine Chemicals Research Institute, GB Marg, Bhavnagar 364 002, India

bApplied Chemistry Department, Sardar Vallabhbhai National Institute of Technology, Surat 395 007, India

cSalt and Marine Chemicals Division, CSIR-Central Salt and Marine Chemicals Research Institute,
GB Marg, Bhavnagar 364 002, India

Email: arvind@csmcri.org/mailme_arvind@yahoo.com

Received 17 September 2015; revised and accepted 27 April 2016

The alterations in properties of protic/aprotic (2-hydroxyethylammonium formate)/ 1-butyl-3-methylimidazolium methyl sulfate) ionic liquids (ILs), based on reciprocal binary mixing concept ([A][B][X][Y]) have been investigated by studying the density, speed of sound, and viscosity of mixtures as a function of temperature. The volume of mixing, isentropic compressibility, excess molar isentropic compressibilities and activation energy of viscous flow have been derived, which indicate a very high level of non-ideality in the mixtures desired to take advantage of improved solvent properties. FTIR spectral analysis and solvatochromic parameters (normalized Reichardt’s parameter, dipolarity/polarizibility, hydrogen bond donor and acceptor coefficients) determined through the solvatochromic probes have been utilized to examine the hydrogen bonding and ion-ion interactions prevailing in the studied systems. Although significant alterations in hydrogen bonding and ion-ion interactions are observed, dispersion type interactions dominate over chemical interactions as indicated by a high positive deviations in the volumes of mixing.

Keywords: Solution chemistry, Ionic liquids, Protic ionic liquids, Aprotic, Reciprocal binary mixing

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 554-559

 

 

Vapour phase hydrogenation of aqueous levulinic acid to γ-valerolactone over CuZnAlO hydrotalcite

V Swarna Jaya* & Medak Sudhakar

Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology,
Hyderabad-500 007, India

Email: swarnajv@gmail.com

Received 29 October 2015; revised and accepted 22 April 2016

Vapour phase hydrogenation of levulinic acid to γ-valerolactone has been accomplished in aqueous phase over copper-zinc-aluminum hydrotalcite, prepared by co-precipitation method using nitrate salts as their precursors. The hydrotalcite system exhibits superior activity in the hydrogenation and cyclization of 10% aqueous solution of levulinic acid with >99% selectivity for γ-valerolactone at 275 oC under atmospheric pressure of hydrogen (flow rate of H2-30 mL/min).

Keywords: Hydrogenation, Vapour phase hydrogenation, Hydrotalcites, Levulinic acid, γ-Valerolactone

 

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 560-565

 

 

Hydrolytic cleavage of paraoxon and parathion by oximate and functionalized oximate ions: A comparative study

Hitesh K Dewangana, Neha Kandpala, Rekha Nagwanshib & Manmohan L Satnamia,*

aSchool of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (CG) 492 010, India

bDepartment of Chemistry, Govt Madhav Science PG College, Ujjain (MP) 456 010, India

Email: manmohanchem@gmail.com

Received 15 December 2015; revised and accepted 20 April 2016

Bimolecular reactions of O,O-diethyl-O-p-nitrophenylphosphate (paraoxon) and O,O-diethyl-O-p-nitrophenyl phosphorothioate (parathion) with oximate (pyridinealdoxime 2-PyOx- and 4-PyOx-) and its functionalized oximate, 4-(hydroxyimino)methyl)-1-alkylpyridinium bromide ions (alkyl = C10H21 (4-C10PyOx-); alkyl = C12H25 (4-C12PyOx-)) have been investigated in aqueous and cationic micellar media of cetylpyridinium bromide, cetyltrimethyl-ammonium bromide and cetyltetradecyltrimethylammonium bromide at pH 9.5 and 27 oC. Under the micellized condition, a 1.2×103 fold and 9.0×106 fold rate enhancement over the aqueous reaction of paraoxon (ko = 7.5×10-8 s-1) and parathion (ko = 9.5×10-11) is observed.

Keywords: Surfactants, Cationic surfactants, Hydrolytic cleavage, Cleavage reactions, Paraoxon, Parathion, Oximate, Functionalized oximate

 

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 566-570

 

 

Synthesis of heteroatom-doped ZnO nanoparticles as an efficient visible light photocatalyst and its photoelectrochemical performance

Wenjie Wu, Xiaodan Zhu, Qiaoqiao Yin, Linxiang Tan, Xiaoxia Ke & Ru Qiao*

College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China

Email: qiaoru@zjnu.cn

Received 21 December 2015; revised and accepted 28 April 2016

Heteroatom-doped ZnO nanoparticles (Zn1-xNixO NPs) have been synthesized by a simple solvothermal approach. The photocatalytic activity of the products has been evaluated by a photoassisted degradation of Rhodamine B in aqueous solution under visible light irradiation. All the heteroatom-doped semiconductors exhibit better photocatalytic activities than pure ZnO, with the 1 mol% Ni2+-doped ZnO showing the best photocatalytic activity. From the transient photocurrent response and electrochemical impedance spectroscopic experiments it is observed that the photogenerated charges of the Ni-doped ZnO show longer lifetime and higher separation than that of pure ZnO, leading to its superior visible light photoactivity. The active species tests indicate that the hydroxyl radical and active holes were primarily responsible for the enhanced photocatalytic performance of Rhodamine B, and the superoxide radical takes part partially in the oxidation process. A possible photocatalytic mechanism is proposed. Good photostability and reusability of the product show that the studied nanoparticles have potential application in dye wastewater treatment.

Keywords: Catalysts, Photocatalysts, Zinc oxide, Ni doping, Nanoparticles, Photoelectrochemical properties

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 55A, May 2016, pp. 571-575

 

 

Utilization of sodium montmorillonite clay for enhanced electrochemical sensing of amlodipine

A Mohamed Sikkandera, C Vedhib & P Manisankarc, *

aDepartment of Chemistry, Velammal Engineering College, Chennai 600 066, Tamil Nadu, India

bDepartment of Chemistry, VO Chidambaram College, Tuticorin 628 008, Tamil Nadu, India

cDepartment of Industrial Chemistry, Alagappa University, Karaikudi 630 003, Tamil Nadu, India

Email: pms11@rediffmail.com/ pmsankarsiva@yahoo.com

Received 30 November 2015; revised and accepted 2 May 2016

Nanosize surface of sodium montmorillonite has been prepared via sonication and deposited on glassy carbon electrodes for use as working electrode in a highly sensitive electrochemical biosensor for the detection of trace amounts of the calcium channel blocking drug, amlodipine. The cyclic voltammetric behaviour of amlodipine is studied in the pH range of 1.0−13.0. In alkali medium (pH 13.0) the sensor shows good response. Cyclic voltammograms show one oxidation peak and one broad reduction peak, which may be due to the oxidation of secondary amino group and reduction of chlorine and nitro groups respectively. Plots of log peak current and potential when correlated with log scan rate, indicate irreversible electron diffusion controlled redox reaction. The optimum conditions have been established by differential pulse stripping voltammetry. The anodic peak current is linear with concentration of the analyte at optimum conditions; the detection limit has been determined to be 0.01 mg/mL. A simple, sensitive and time-saving differential pulse stripping voltammetric procedure has been developed for estimation of amlodipine in its formulations as tablets.

Keywords: Electroanalytical chemistry, Electrochemistry, Sensors, Clays, Sodium montmorillonite,
Cyclic voltammetry, Differential pulse stripping voltammetry, Amlodipine