Indian Journal of Chemistry

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

http://www.niscair.res.in; http://nopr.niscair.res.in

 

Total visitors:2,063 since: 07-09-09

 

VOLUME 48A

NUMBER 9

September 2009

CONTENTS

Rapid Communication

 

1201

 

Use of [PtII(H2O)4]2+ complex for development of ionic-polymer-metal-composite actuators

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Debabrata Chatterjee

 

 

 

 

Platinization of ionic-polymer Nafion has been achieved by using tetraaquaplatinum(II) complex. A micro-actuator has been developed with this ionic-polymer-metal-composite material which actuates under an operating voltage of +3.0 V.

 

 

Papers

 

1204

 

Arylazoimidazole-W(0)-carbonyl complexes: Synthesis, characterization, electrochemistry, photophysical studies and correlation with DFT computed data

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Papia Datta & Chittaranjan Sinha*

 

 

 

Reaction of W(CO)6 and 1-alkyl-2-(arylazo)imidazoles (RaaiR/) yields tetracarbonyl complexes with the composition, [W(CO)4(RaaiR/)]. Electrochemistry of the complexes shows oxidation of tungsten, W(0) ® W(+1), at 0.70-1.00 V. DFT calculations show that the HOMO is composed of W (63%) and CO (34%) orbitals while LUMO is made up of only imidazole characteristics (>75%). The complexes are emissive at room temperature, with [W(CO)4(1-alkyl-2-(naphthyl-b-azo)imidazole)] showing higher  quantum yield (f = 0.50-0.63) than the others.

 

 

1212

 

Synthesis and characterisation of oxomolybdenum(V) and dioxomolybdenum(VI) complexes with Schiff base derived from isonicotinoylhydrazide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M L Harikumaran Nair* & D Thankamani

 

 

 

 

Synthesis of some new oxomolybdenum(V) and dioxomolybdenum(VI) complexes with a Schiff base,
3-methoxysalicylaldehydeisonicotinoylhydrazone, derived from
3-methoxysalicylaldehyde and isonicotinoylhydrazide are reported.

 

 

 

1219

 

Experimental and theoretical vibrational spectroscopic and HOMO, LUMO studies of
1,3-dimethylbarbituric acid

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S Chandra, H Saleem, N Sundaraganesan* &
S Sebastian

 

 

 

 

The Fourier transform gas phase (5000-400 cm-1) and solid phase (4000-400 cm-1) infrared spectra as well as Raman spectra
(3500-50 cm-1) of 1,3-dimethylbarbituric acid have been recorded. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The theoretical FT-IR and FT-Raman spectra for the title molecule have been constructed.

 

 

 

1228

 

Kinetic studies on effects of EDTA and surfactants on reduction of vanadium(V) to vanadium(IV) in sulphuric acid medium

 

 

 

 

 

 

 

 

 

 

 

 

A P Mishra*, Raju Khan & Ravi Ranjan Pandey

 

 

 

 

Reduction kinetics of vanadium(V) to vanadium(IV) by EDTA and effects of surfactant have been studied using thiourea as a reductant at 40±1 °C in acidic medium at 350 nm. Electronic absorption spectra of the reaction products suggest the formation of aqua vanadium(IV) and vanadium(IV)-EDTA complex in the absence and presence of EDTA respectively. The oxidation of thiourea by vanadium(V) has also been studied in the presence of surfactants. Sodium dodecyl sulphate and TritonX-100 catalyze the reaction whereas cetyltrimethylammonium bromide has no effect. The single-electron sequence is confirmed by the formation of vanadium(IV) aqua-ion. The experimentally determined intermediate complex formation constant,
K
es is 34 mol-1 dm3.

 

Notes

 

1235

 

The selectivity of nucleobases in DNA binding by Ru(phenanthroline)3 complex

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P Hazarika, B Bezbaruah, A Gogoi, P Das,
O K Medhi & C Medhi*

 

 

 

 

Interaction of Ru(phenanthroline)3 with various sites of nucleobases like guanine, adenine, cytosine and thymine has
been investigated by ab initio quantum mechanical calculations. The O6 of guanine and O2 of cytosine can form more stable Ru coordinated complexes than N7 of guanine. Formation of bridged hydrogen bonds between polarized atomic sites of this complex and all the nucleobases (except thymine) has been observed.

 

 

 

1242

 

Intermolecular interaction studies of binary mixtures of a ketoester and carbonyl compounds. I: Excess volumes of binary mixtures of ethyl acetoacetate with aliphatic ketones at 298.15K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Welford-Abbey Lolo Izonfuo* &

Ayasen Jermaine Kemeakegha

 

 

 

 

Density data on binary mixtures of ethyl acetoacetate and some aliphatic ketones have been obtained at 298.15K over the entire range of solvent composition. In mixtures where dipole-dipole interactions between like molecules predominate, excess volumes are usually positive. When dipole-dipole interactions between unlike molecules predominate, excess volumes are negative.

 

 

 

1247

 

Studies on complexation between urea and
18-crown-6 in aqueous solutions at 298.15K

 

 

 

 

 

 

 

 

 

 

 

 

Preeti Tomar

 

 

 

 

Osmotic vapor pressure and density measurements have been carried out for binary aqueous urea solutions (0.1m − 1m) and ternary aqueous solutions containing three different concentrations of 18-crown-6 (0.1, 0.2 and 0.5m) at 298.15K. The results are explained in terms of 1:4 stoichiometric complex formation, with urea at the lowest concentration of 18-crown-6 having a small equilibrium constant value. At higher 18-crown-6 concentrations, water forms hydrogen bond with crown ring oxygen atoms and hydrophobic interaction between 18-crown-6 molecules outweighs the interaction of urea with 18-crown-6 molecules, resulting in salting out of urea molecules.

 

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1201-1203

 

Use of [PtII(H2O)4]2+ complex for development of
ionic-polymer-metal-composite actuators

 

Debabrata Chatterjee

 

Chemistry Group, Central Mechanical Engineering Research Institute, Durgapur 713 209, India

Email: dchat57@hotmail.com

 

Received 21 July 2009, accepted 18 August 2009

 

Platinization of ionic-polymer Nafion has been achieved by using tetraaquaplatinum(II) complex. Surface deposition of platinum has been characterized by AMF studies. A micro-actuator has been developed with this ionic-polymer-metal-composite material which actuates under operating voltage of +3.0 V. The results of actuation and force/displacement studies are discussed.

 

Keywords: Composites, Ionic polymer metal composites, Actuators, Platinum, Nafion

 

IPC Code: Int. Cl.9 C07F 15/00

 

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1204-1211

 

Arylazoimidazole-W(0)-carbonyl complexes: Synthesis, characterization, electrochemistry, photophysical studies and correlation with DFT computed data

Papia Datta & Chittaranjan Sinha*

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

Email: c_r_sinha@yahoo.com

Received 26 February 2009; revised and accepted 18 August 2009

Reaction of W(CO)6 and 1-alkyl-2-(arylazo)imidazoles (RaaiR/) yields tetracarbonyl complexes of the composition, [W(CO)4(RaaiR/)]. The complexes have been characterized by different spectroscopic methods (FT-IR,UV-Vis, 1H-NMR and mass spectrometry). Electrochemistry of the complexes shows oxidation of tungsten, W(0) ® W(+1) at potential
0.70-1.00 V. Geometry of representative complexes in each group of ligand optimized by DFT calculations, shows that the HOMO is composed of W (>60%) and CO (>30%) orbitals while LUMO is carrying only azoimidazole characteristics (>75%). [W(CO)4(1-methyl-2-(phenylazo)imidazoles)] shows lowest energy in the series.  The complexes exhibit emission at room temperature, with [W(CO)4(1-alkyl-2-(naphthyl-b-azo)imidazole, b-NaiR)] showing higher  quantum yield
(f = 0.50-0.63) than others.

 

Keywords: Coordination chemistry, Arylazoimidazoles, Fluorescence, DFT calculations, Tungsten

 

IPC Code: Int. Cl.9 C07F11/00

 

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1212-1218

 

Synthesis and characterisation of oxomolybdenum(V) and dioxomolybdenum(VI) complexes with Schiff base derived from isonicotinoylhydrazide

M L Harikumaran Nair* & D Thankamani

Department of Chemistry, University College, Thiruvananthapuram 695 034, India

Email: drmlhnair@gmail.com

Received 11 May 2009; revised and accepted 3 August 2009

Synthesis of some new oxomolybdenum(V) and dioxomolybdenum(VI) complexes with a Schiff base,
3-methoxysalicylaldehydeisonicotinoylhydrazone derived from 3-methoxysalicylaldehyde and isonicotinoylhydrazide are reported. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility data, IR, UV-vis, EPR, 1H NMR and FAB mass spectral studies. The physico-chemical studies and spectral data indicate that the ligand acts as a monovalent tridentate chelating agent. The FAB mass and X-band EPR spectra indicate that the pentavalent Mo in the complex [MoO(MSINH)Cl2] is monomeric in nature. The X-ray diffraction studies of [MoO(MSINH)Cl2] correspond to orthorhombic crystal lattice with unit cell dimensions: a = 8.043Ả, b = 12.49Ả and c = 14.936Ả. All the complexes are found to be neutral with distorted octahedral geometry. The thermal properties of the complex [MoO(MSINH)Cl2] have been investigated by thermogravimetric techniques. The ligand, [MoO(MSINH)Cl2] and [MoO2(MSINH)Cl] have been screened for their in vitro anticancer and antibacterial activity. The complex, [MoO(MSINH)Cl2], exhibits much higher activity than the ligand (MSINH) and its dioxocomplex, [MoO2(MSINH)Cl].

Keywords: Coordination chemistry, Molybdenum, Schiff bases, Anticancer activity, Antibacterial activity

 

IPC Code: Int. Cl.9 C07C251/02; C07F11/00

 

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1219-1227

 

Experimental and theoretical vibrational spectroscopic and HOMO, LUMO studies of 1,3-dimethylbarbituric acid

S Chandra, H Saleem, N Sundaraganesan* & S Sebastian

Department of Physics (Engg.), Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India

Email: sundaraganesan_n2003@yahoo.co.in

Received 30 March 2009; revised and accepted 20 August 2009

The Fourier transform gas phase (5000-400 cm-1), solid phase (4000-400 cm-1) infrared spectra as well as Raman spectra (3500-50 cm-1) of 1,3-dimethylbarbituric acid have been recorded. Quantum chemical calculations of energies, geometrical structure and vibrational wave numbers of 1,3-dimethylbarbituric acid have been made by density functional method with 6-31G(d,p) as basis set. The best level of theory in order to reproduce the experimental wave numbers is B3LYP method with the 6-31G(d,p) basis set. A detailed interpretation of the infrared and Raman spectra of 1,3-DMBA is also reported. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The theoretical FT-IR and FT-Raman spectra for the title molecule have been constructed.

Keywords: Theoretical chemistry, Vibrational spectroscopy, IR spectroscopy, Raman spectroscopy

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1228-1234

 

Kinetic studies on effects of EDTA and surfactants on reduction of vanadium(V)
to vanadium(IV) in sulphuric acid medium

A P Mishraa, *, Raju Khanb & Ravi Ranjan Pandeyb

a Department of Science and Technology, Ministry of Science and Technology,
Technology Bhavan, New Delhi 110 016, India

Email: apmishra@nic.in

bEngineering Material Division, National Physical Laboratory, New Delhi 110 012, India

 

Received 17 April 2009; revised and accepted 19 August 2009

Reduction kinetics of vanadium(V) to vanadium(IV) by EDTA and effects of surfactant have been studied using thiourea as a reductant at 40±1°C in acidic medium at 350 nm. UV-vis and ESR spectral techniques have been used to confirm the reduction product of vanadium(V). Electronic absorption spectra of the reaction products suggest the formation of aqua vanadium(IV) and vanadium(IV)-EDTA complex in the absence and presence of EDTA, respectively. The oxidation of thiourea by vanadium(V) has also been studied in the presence of surfactants. The anionic sodium dodecyl sulphate and
non-ionic TX-100 surfactants catalyze the reaction whereas the cationic surfactant, cetyltrimethylammonium bromide, has no effect. The single electron sequence is confirmed by the formation of vanadium(IV) aqua ion. The experimentally determined intermediate complex formation constant, Kes is 34 mol-1 dm3.

Keywords: Kinetics, Reaction mechanisms, Surfactants, Reductions, EDTA

 

IPC Code: Int. Cl.9 C07B31/00

 

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1235-1241

 

The selectivity of nucleobases in DNA binding by Ru(phenanthroline)3 complex

P Hazarika, B Bezbaruah, A Gogoi, P Das, O K Medhi & C Medhi*

Chemistry Department, Gauhati University, Guwahati 781 014, India

Email:chitrani@sify.com

Received 19 May 2009; revised and accepted 18 August 2009

Interaction ability of Ru(phenanthroline)3 with various sites of nucleobases like guanine, adenine, cytosine and thymine has been investigated by ab initio quantum mechanical calculations. While the N7 of guanine is found to be a susceptible site for binding with Ru metal, the other sites of nucleobases can also bind with this metal centre. The O6 of guanine and O2 of cytosine can form more stable Ru coordinated complexes than N7 of guanine. Formation of bridged hydrogen bonds between polarized atomic sites of this complex and all the nucleobases (except thymine) has been observed. Such hydrogen bonds may also stabilize the complex better than the direct Ru coordinated complexes inside DNA.

 

Keywords: Coordination chemistry, Theoretical chemistry, Ab initio calculations, DNA binding, Sequence specificity, Nucleobases, Ruthenium, Guanine, Adenine, Cytosine, Thymine

 

IPC Code: Int. Cl.9 C07F15/00

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1242-1246

 

Intermolecular interaction studies of binary mixtures of a ketoester and carbonyl compounds. I: Excess volumes of binary mixtures of ethyl acetoacetate with aliphatic ketones at 298.15K

Welford-Abbey Lolo Izonfuo* & Ayasen Jermaine Kemeakegha

Department of Chemical Sciences, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria

Email: Welfordabbey@yahoo.com

Received 26 March 2009; revised and accepted 20 August 2009

Density data on binary mixtures of ethyl acetoacetate and aliphatic ketones containing four to six carbon atoms have been obtained with a single capillary pyknometer at 298.15K over the entire range of solvent composition. Excess volumes of the binary mixtures, calculated from the density data, for the binary mixtures of ethyl acetoacetate with the straight chain ketones, butan-2-one and pentan-3-one are negative over the entire range of solvent composition. The negative excess volumes are attributed to volume reductions arising from the fitting of the ketone molecules having smaller molecular volumes into the ethyl acetoacetate molecules with larger molecular volumes. The excess volumes of the branched aliphatic ketones, 3-methylbutan-2-one and 4-methylpentan-2-one are negative in some regions of solvent composition and positive in other regions of solvent composition. The negative excess volumes in the binary mixtures of ethyl acetoacetate and the branched ketones are attributed to strong dipole-dipole interactions between unlike molecules while the positive excess volumes are attributed to a mutual loosening of dipole-dipole interactions between like molecules.

Keywords:Thermodynamics, Intermolecular interactions, Ketones, Ketoesters, Excess volumes

 

Indian Journal of Chemistry

Vol. 48A, September 2009, pp. 1247-1250

 

Studies on complexation between urea and 18-crown-6 in aqueous solutions
at 298.15K

Preeti Tomar

Department of Engineering Science, JSPM’S Rajarshi Shahu College of Engineering, Tathawade, Pune 411 033, India

Email:preetitomar@gmail.com

Received 5 March 2009; revised and accepted 17 August 2009

Osmotic vapor pressure and density measurements have been made for binary aqueous urea solutions (0.1m-1m) and ternary aqueous solutions containing three different concentrations of 18-crown-6 (0.1, 0.2 and 0.5m) at 298.15K. The molal activity coefficients of urea, water and 18-crown-6 in binary as well as in ternary solutions have been calculated. Thermodynamic equilibrium constant, salting coefficient and molecular interaction parameters have been determined. The results are explained in terms of 1:4 stoichiometric complex formation with urea at the lowest concentration of 18-crown-6 having a small equilibrium constant value. At higher 18-crown-6 concentrations, water forms hydrogen bond with crown ring oxygen atoms and hydrophobic interaction between 18-crown-6 molecules outweighs the interaction of urea with 18-crown-6 molecules, resulting in salting out of urea molecules.

Keywords: Solution chemistry, Complexation, Urea, Crown ethers