Indian Journal of Chemistry

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

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

 

VOLUME 49A

NUMBER 4

April 2010

CONTENTS

 

401

 

CuO, K2O and V2O5 supported on ceria-titania: Synthesis, characterization and application for diesel soot combustion

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K Joseph Antony Raj & B Viswanathan*

 

 

 

 

Diesel soot oxidation with CuO/V2O5/K2O/CeO2-TiO2 catalyst samples is reported. Mixtures of the catalysts with diesel soot lower the oxidation temperature from 601 to 427 °C. Sample with 12.5 % K2O is most active with peak activity at 427 °C. The activity is further improved on incorporation of K-Cu-V, due to the mobility of potassium on melting. Interaction between K2O and titania results in formation of potassium titanate. The samples loaded with higher concentrations of potassium show the formation of solid solutions with the oxides of Ce, K and V. The catalyst with 12.5 wt.% K2O, 7.5 wt.% V2O5 and 2 wt.% CuO exhibits complete combustion at Tmax 427 °C.

 

 

407

 

Azonium-ammonium tautomerism and inclusion complexation of 4-amino-2′, 3-dimethylazobenzene

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A Antony Muthu Prabhu, G Venkatesh,
R K Sankaranarayanan, S Siva & N Rajendiran*

 

 

 

Spectral characteristics of 4-amino-2′, 3-dimethylazobenzene,
4-aminoazobenzene
and azobenzene have been studied in various solvents, varying hydrogen ion concentrations and in
b-cyclodextrin. Solvent study shows that the azo form is present only in GBC and AAB molecules. In acid solutions, an unusual red shift is observed in the monocation, suggesting that the azonium-ammonium tautomer is present in both molecules. The absorption maximum at ~500 nm is due to the azonium cation, while that at ~320 nm originates from the ammonium cation. In b-CD solutions, the increase in the fluorescence intensity and the large bathochromic shift in S1 state indicate that both GBC and
AAB form 2:2 inclusion complexes, whereas AB forms
1:1 inclusion complex.

 

 

 

 

 

 

418

 

Kinetics and mechanism of acid bromate oxidation of substituted 4-oxo acids

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cherkupally Sanjeeva Reddy* & Padma Sunitha Manjari

 

 

 

 

Kinetics and mechanism of oxidation of substituted 4-oxo-4-arylbutanoic acids  by acid bromate (uncontaminated with Br2) in aqueous acetic acid medium has been studied.

 

 

 

 

425

 

Structure-property studies in (0.8-x)MoO3-0.2B2O3-xK2O (0≤x≤0.25) glasses by spectral and magnetic measurements

 

 

 

 

 

 

 

 

 

B B Das* & R Ambika

 

 

 

 

Glasses of the (0.8-x)MoO3-0.2B2O3-xK2O (0 ≤ x ≤ 0.25) system have been prepared by air quenching the melt in the range
1073-1173 K. IR data at 300 K show the presence of octahedral [OMoO5/2]-, tetrahedral [BO4/2],-trigonal [BO3/2] and n free oxygen containing trigonal [BOn+(3-n)/2 ]n- (n = 1, 2, 3) units. The Mo5+(4d1) ion concentration is one order of magnitude lower than that of Mo6+ ions. Partially resolved hyperfine structures indicate that the small polaron hopping depends on temperature as well as on the glass network. Calculated value of magnetic susceptibility
(~10-5 emu/gG) indicates weak paramagnetism in the glasses at
300 K. The observed electron paramagnetic resonance shows that the lineshapes vary from axially symmetric in binary to isotropic in ternary compositions at 300 and 77 K.

 

Notes

 

431

 

DFT study on the reaction of La (2D) with CH3CHO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Guoliang Dai*, Hao Chen, Hua Yan,
Chuanfeng Wang & Aiguo Zhong

 

 

 

 

Reaction mechanism of the ground state (2D) La atom with CH3CHO is studied by density functional theory. The reaction starts with formation of η2-CH3CHO-metal complex followed by C−C, C−O, aldehyde C−H and methyl C−H activation to give four products, i. e., LaCO+CH4, HLaCH3+CO, LaO+C2H4 and LaCH2CO+H2. Since the energies of the intermediates, transition states and products lie below those of the reactants (except TS38), the reaction is expected to occur spontaneously over the doublet potential energy surface.

 

 

437

 

Synthesis and structural characterization of
1-methylpiperazinediium tetrasulfidotungstate monohydrate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bikshandarkoil R Srinivasan*, Ashish R Naik,
Christian Näther & Wolfgang Bensch

 

 

 

The organic cation, [WS4]2- anion and the lattice water in
1-methylpiperazinediium tetrasulfidotungstate monohydrate are linked with five varieties of H-bonds.

 

 

 

442

 

Kinetics and mechanism of silver(I) catalyzed oxidation of valine by cerium(IV) in acid perchlorate medium

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M B Yadav, Vijay Devra & Ashu Rani*

 

 

 

 

Kinetics of silver(I) catalyzed oxidation of valine with cerium(IV) has been studied in perchloric acid medium. A decrease in rate with increase in [Ce(IV)] is observed. The reaction exhibits fractional dependence on valine due to formation of an adduct with silver(I).

 

 

 

 

448

 

Electroluminescent characteristics of bis(5-chloro-8-hydroxyquinolinato) zinc(II) complex

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Anita Sharma, Devender Singh, Partap S Kadyan, Amit Kumar, Kapoor Singha, Gayatri Chauhan & Ishwar Singh*

 

 

 

 

A zinc(II) complex with 5-chloro-8-hydroxyquinoline has been used as emitting material to produce yellow light. On excitation by UV light at 385 nm, a thin film of the complex exhibited fluorescence at 550 nm. Multilayer organic electroluminescence devices fabricated using this fluorescent material produce emission with good chromaticity (CIE coordinates: x = 0.313 and y = 0.576). Maximum luminance of 466 cd/m2 is achieved when
2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane is used as dopant in 4,4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl at 12 V.

 

 

 

 

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