008231   Pape Gowd C T;Srinivas J;Rao Suryanarayana V (Chemistry Dep, Sri Krishnadevaraya Univ, Anantapur-515 003) : Spectrophotometric determination of microgram quantities of palladium (II) in alloys. Res J Chem Envir 2008, 12(1), 58-60.

A method for the spectrophotometric determination of Pd(II) has been developed by using furfur aldehyde thiosemicarbazone (FFTSC) as complexing agent. Pd(H) reacts with FFTSC in the pH range 1 to 5 to form yellow coloured solution. The complex shows maximum absorption in a buffer solution of pH 1. λ_max is 360.5 nm. The composition of the complex is 1:4 (M:L). Beer's law is obeyed in the range 0.170 μg/ml to 1.703 μg/ml. The molar absorptivity and Sandel sensitivity are calculated as 3.9911 X 10⁴ L mol^-1 cm^-1 and 0.0026664 μg cm^-2 respectively. The method has been successfully applied for Pd(II) determination in alloys.

2 illus, 2 tables, 8 ref

008230   Nagarajan K (Hikal R and D Centre, , Bannerghatta Road, Bangalore-560 076, Email: k_nagarajan@hikal.com) : T R Govindachari's natural products chemistry. Resonance 2008, 13(6), 519-39.

Prof. Govindachari's research career, which spanned more than five decades, was almost completely devoted to the chemistry of Indian plants wherein he made seminal contributions. His work was notable for two major reasons: Firstly, it focused on the isolation and structure elucidation of plant constituents, occasionally supported by total or partial synthesis. Secondly his interests were copiously distributed among different classes, alkaloids, terpenes, oxygen heterocycles and other systems. It is impossible to do full justice to his work and this article provides only a selection which will give a flavor of his contributions.

10 illus, 4 ref

008229   Murali Krishna M P S;Moses G S;Murali Krishna K V S G (Chemistry Dep, Govt. Polytechnic College, Bommuru, Rajahmundry, Email: anda1143@gmail.com) : Characterization of lignin isolated from paper mill effluent. Res J Chem Envir 2007, 11(3), 55-64.

Waste is not a waste it will become resource if properly utilized. Instead of releasing lignin through effluents into water bodies from paper & coyer board manufacturing units, It may be better option to extract it from effluents and to use binder, dispersant, emulsifier, sequestrant in an eco friendly way. Here an attempt has been made to characterize the lignin isolated from effluents of Andhra Pradesh Paper Mill located at Rajahmundry by elemental analysis, methoxyl analysis and molecular weight analysis, UV, IR and ¹H NMR spectroscopy. The C₉ formula for lignin was C₉H_9.36O_4.56 (OCH₃)_1.23and the lignin was guaiagyl-syringyl type.

10 illus, 3 tables, 22 ref

008228   Mulwad V V;Mayekar S A (Chemistry Dep, The Institute of Science, 15, Madam Cama Road, Mumbai-400 032, Email: vinata_mulwad@hotmail.com) : Synthesis and antimicrobial screening of 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-yalzo)-2-mehyl-6-morpholin-4-yl- 2, 3-dihydro-3H-pyrimidin-4-one and 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)-2-methyl-6-piperidin-1-yl -2,3-dihydro-3H-pyrimidin-4-one. Indian J Chem-Sect B 2007, 46(11), 1873-8.

The coupling reaction of the diazonium solution of the 6-aminocoumarins (1a-c) with malononitrile affords the corresponding 2-[(4,7-dimethyl-2-oxo-2H-benzopyran-6-yl)-hydra-zonal]-malononitrile (2a-c) which on refluxing with morpholine and piperidine separately yields the corresponding 3-amino-2-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)-3-morpholin-4-yl- acrylonitrile (3a-c) and 3-amino-2-(4,7-dimethyl-2-oxo-2H-benzopyran-6-yalzo)-3-piperidin-1-yl- acrylonitrile (3d-f) respectively. The enaminonitrile derivatives (3a-f) on heating with acetic anhydride give the corresponding 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)-2-methyl-6-morpholin-4-yl -2,3-dihydro-3H-pyrimidin-4-one and 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)-2-methyl-6-piperidin-1-yl -2,3-dihydro-3H-pyrimidin-4-one (4a-f). The structures of the compounds (2a-c), (3a-f) and (4a-f) have been established on the basis of spectral and analytical data. All the above compounds have been screened for their antimicrobial activities and are found to possess significant antibacterial activities.

^ssc2 tables, 12 ref

008227   Kumar G (Chemistry Dep, Botswana Univ, P/Bag UB 00704, Gaborone, Botswana, Email: kumarg@mopipi.ub.bw) : Synthesis and characterization of mixed ligand cobalt(II) complexes of iminodiacetic acid and hippuric acid. Res J Chem Envir 2007, 11(3), 87-9.

Mixed ligand cobalt (II) complexes, Na [Co {NH {CH₂COO)₂} (C₆H₅CONH CH₂ COO). H₂O].8H₂O and Na[Co{NH (CH₂ COO)₂}(C₆H₅ CO NH CH₂ COO). H₂O].4H₂O formed with iminodiacetic acid and hippuric acid have been synthesized and characterized by their elemental analysis, infra-red spectra, electronic spectra and magnetic measurements. Iminodiacetic acid shows a tri-dentate behaviour with the coordination occurring through the carboxylate oxygen atoms and the nitrogen atom. Hippuric acid acts as a bidentate ligand coordinating through the carboxylate oxygen atom and the nitrogen of the amido group. The sixth coordination position is satisfied by the water molecule.

1 illus, 2 tables, 16 ref

008226   Kotoky J;Kalita M;Gautam Kumar;Sarmah;Das B (Life Sciences Dep, Insitute of Advanced study in Science and Technology, Guwahati-781 035, Email: jkotoky@yahoo.com) : Molecular and crystal structure of 6α-acetoxy azadirone. Indian J Chem-Sect B 2007, 46(11), 1879-82.

The crystal structure of the title compound, 1 has been determined by X-ray crystallographic techniques. The compound crystallizes in orthorhombic space group P2₁2₁2₁ with unit cell parameters: a=10.699(3) Å, b=15.510(4) Å, c=16.626(4) Å, Z=4. The structure has been solved by direct methods and refined to R=0.0585 for 6681 independent reflections.

^ssc3 illus, 2 tables, 14 ref

008225   Ketcha M J;Manga N H;Daouda K;Tchoua N P H (Physical and Theoretical Chemistry Laboratory, Faculty of Science, Yaounde Univ, I, P.O. Box 812, Yaounde, Cameroon, Email: jketcha@yahoo.com ) : Kinetic and equilibrium studies of the adsorption of nitrates ions in aqueous solutions by activated carbons and zeolite. Res J Chem Envir 2007, 11(3), 47-51.

The batch removal of nitrates from aqueous solution using three adsorbents- Granular Activated Carbon (GAC), powdered activated Carbon (PAC) and a Zeolite (molecular sieve 5Angstrum) was investigated in this study. The influence of initial concentration of nitrates ions (100 to 700 mg/ L) and pH (2.86 to 12.13) have been reported. Adsorption of nitrate ions is highly pH-dependent with the optimum pH for the removal found to be in the range 2.8 < pH < 6.5 for the three types of adsorbents. Comparison of a first order and second order kinetic model applied to the adsorption of the nitrate ions from solution showed better agreement of the experimental data with the second order kinetic model.

2 illus, 1 table, 19 ref

008224   Jain S;Ameta Suresh C (Chemistry Dep, College of Science Univ, ML Sukhadia Univ, Udaipur-313 002, Email: ameta_sc@yahoo.com) : Photocatalytic oxidation of arabinose and glucose over cadmium sulphide. Res J Chem Envir 2008, 12(1), 61-4.

The photocatalytic oxidation of arabinose and glucose on cadmium sulphide was carried out and the progress of reaction was monitored spectrophotometrically. The effect of the variation of various parameters such as pH, concentration, amount of cadmium sulphide, light intensity, etc. on this photocatalytic oxidation was observed. A tentative mechanism for this degradation has also been proposed.

5 tables, 12 ref

008223   Heasley Victor L;et al. (Chemistry Dep, Point Loma Nazarene Univ, San Diego, CA 92106, USA, Email: vheasley@pointloma.edu) : Reactions of 2, 4, 6-trichlororesorcinol and pentachlororesorcinol with monochloroamine in methanol: investigation of products and mechanisms. Res J Chem Envir 2007, 11(3), 22-8.

Paper presents a comparison of the reactions of two model compounds of the humic acids with monochloramine, NH₂Cl. The humic acids, which are present in drinking water, react with chlorinating agents when water is chlorinated to give numerous contaminants. The model compounds discussed in the paper are 2, 4, 6-trichlororesorcinol (3), called TCR here, and 2, 2, 4, 4, 6-pentachlorocyclohex-5-en-l,3-dione (4), which is often referred to as pentachlororesorcinol or PCR (the name used here). A few years ago we reported on the reactions of (3) and (4) with NH₂Cl in ether, reactions which both gave the same products. For several years it is investigated that the reaction of (4) with NH₂Cl in methanol, MeOH, where 2,2,4,4, 6-pentachloro-5-methoxy-1,3-dione (6) was the major product. Surprised when TCR (3) in MeOH with NH₂Cl gave only a trace of (6) and the following major products: (E-, Z-) methyl 2, 2, 4, 6-tetrachloro-6-3-oxohex-4-enoate (8,9) and (E-, Z-) methyl 2,4,6-trichloro-2,6-dimethoxy-3-oxohex-4-enoate (10, 11). The TCR (3) products were minor in the reaction of PCR (4) with NH₂Cl in MeOH. Other products were formed in the two reactions and are listed in Table 1, but the differences in amounts between products (6), (8/9) and (10/11) confirmed that (3) was not on the reaction pathway to give (4) in MeOH, as had occurred in our earlier study in ether. In addition, the reaction of (3) with NH₂Cl in MeOH was slow (24 hrs for completion); (4) and NH₂Cl reacted rapidly (complete in 10 mins). We suggest that the reactions of (3) and (4) are both occurring by ion-radical mechanisms which are described in detail in the paper.

4 illus, 1 table, 12 ref

008222   Gutman I;Furtula B (Faculty of Science, University of Kragujevac, P.O. Box 60, Serbia, Email: gutman@kg.ac.yu) : Graphenes-aromatic giants. Resonance 2008, 13(8), 730-7.

Recently, extremely large benzenoid hydrocarbons have been synthesized. These compounds resemble graphite in many ways, and have been named graphenes. Because of their non-standard properties, graphenes have already found numerous applications, especially as special-purpose materials in electronics. Outlines the basic chemical facts on graphenes.

6 illus, 7 ref

008221   Goswami A;Das R N;Naleen Borthakur (NO, North-East Institute of Science & Technology, Jorhat-785 006, Assam, Email: goswamia@rrljorhat.res.in) : KHSO₄-SiO₂-MeOH an efficient selective solid-supported system for deprotection of alcohols from easters. Indian J Chem-Sect B 2007, 46(11), 1893-5.

KHSO₄-SiO₂ can efficiently deprotect alcohols from esters through transesterification in methanol under mild condition, Easters of aromatic alcohols are easily transesterified at room temperature compared to the corresponding aliphatic or alicyclic alcohol. N-Acetyl compounds and ethers are resistant to the reagent under the above condition. The method is very useful for preparation of bio-diesel methyl ricinoleate from castor oil.

^ssc1 table, 19 ref

008220   Eva C (Faculty of Natural Sciences, Comenius Univ, Mlynska dolina, 842 15 Bratislava, Slovak republic, Email: chmielewska@fns.uniba.sk) : XPS, NMR and S_BET studies of native clinoptilolite functionalized with carbonaceous substances. Res J Chem Envir 2007, 11(3), 65-71.

The paper deals with fabrication of carbonized and hydrophobized clinoptilolite based adsorbents using organic carbon rich substances which were pyrolytic combusted and covered the external zeolite surface. Hydrophobization of the zeolite external surface was accomplished by octadecylammonium surfactant. Both surface modified clinoptilolite dominated zeolites were examined and compared with each other in regard to organic (phenol) and inorganic (chromate, arsenate) pollutants removal from aqueous solutions and so far elaborated composites with surface adsorbed pollutant species were analysed by X-ray photoelectron spectroscopy (XPS). Surface of such a clinoptilolite-rich tuff composite and nuclear magnetic resonance (¹H NMR) measurements were undertaken to supplement the characterization of these advanced nanosized zeolite based materials respectively.

9 illus, 2 tables, 13 ref

008219   da Silva E N (NO, Instituto de Quimica, Universidade Federal Fluminense, UFF, CEP: 24020-150 Niteroi, Rio de Janeiro, Brazil, Email: junior_uff@yahoo.com.br) : Multicomponent reactions as a green approach. Res J Chem Envir 2007, 11(3), 90-1.

A new, green, multicomponent reaction (MCRs) approach offers a straighforward route to generate complexity and diversity in a single operation. MCRs is great tool in combinatorial chemistry.

11 ref

008218   Bian Y J;Bai D S (Chemistry Dept, Langfang Normal College, Hebei, Langfang-0650 00, P.R. China, Email: bianyanjiang@126.com) : The electrosynthesis of pinacols. Indian J Chem-Sect B 2007, 46(11), 1890-2.

Electrosynthesis of pinacols by iron as electrode in acid condition is performed. The influence of electric potential and time on pinacol yield is explored. The optimal reaction conditions are at electric potential 4 V, time 60 min., methanol (6 mL), hydrochloric acid (2N, 2mL), with the yield of pinacols up to 18-81%. The main advantages of the present procedure are milder reaction conditions and operational simplicity.

^ssc1 illus, 2 tables, 13 ref

008217   Agwara M O;Ndifon P T;Ndikontar M K;Atamba M A (Inorganic Chemistry Dep, Faculty of Science, Yaounde Univ I, P.O. Box 812, Cameroon, Email: agwara29@yahoo.com) : Synthesis, characterisation and antimicrobial activities of Co(II), Ni(II), and Cu(II) complexes of hexamethylenetetramine ligand. Res J Chem Envir 2008, 12(1), 87-92.

Hexamethylenetetramine (HMTA, C₆H₁₂N₄) complexes of Co(II), Ni(II), and Cu(II) have been synthesized in ethanol. While the cobalt(II) and copper(II) complexes have one molecule of hexamethylenetetramine, the nickel complex has two molecules. These complexes have been characterised by elemental analyses, infrared and visible spectroscopy, ¹H NMR, conductivity and room temperature magnetic susceptibility measurements. The results suggest octahedral coordination in which the central metal ion is bonded to HMTA and aqua ligands. Antimicrobial activities of the ligand and its derived complexes show that the ligand, HMTA is active against 2 out of 11 tested organisms; the nickel complex [Ni(H₂O)₄(HMTA)₂]Cl₂.5H₂O is active on none and the cobalt complex is active against 4 of the organisms. The copper complex, [(CuCl₂)₂ (HMTA)(H₂O)₂] is active against all the 11 tested organisms, including the yeast, Candida albicans.

1 illus, 5 tables, 34 ref

007174   Zhou X;Zhang A G;Zhou Z Y;Jia Z K;Hou R Y (College of Chemistry & Chemical Engineering, China University of Petroleum, Shangdong, DongYing, 257061, People's Republic of China, Email: zhengyu@mail.qfnu.edu.cn) : Multi-channel reactions of intramolecular proton transfer on serinamide in the ground and excited states: a theoretical study. Indian J Chem-Sect A 2009, 48(3), 315-26.

Multi-channel reactions of intramolecular proton transfer on serinamide in the ground state and excited state have been determined by studying five pairs of mirror-image conformers of serinamide in excited state and eight pairs in ground state. Density function theory calculations have been made at B3LYP/6-311++G** level. Four different channels for intramolecular proton transfer are confirmed by theoretical calculations for the excited and ground states. For the excited state intramolecular proton transfer, process CH2 (H10 from CH to O2) is considered to be the most favorable channel with the lowest energy barrier (E_a = 86.267 kJ/mol). At the same time, process CH1 (H9 from N3 to O2) is calculated to be both thermodynamically and kinetically favored for the ground state intramolecular proton transfer. Comparing the activation energies of these channels, it may be inferred that the activation energy needed by the excited state intramolecular proton transfer process is much lower than that required by ground state intramolecular proton transfer process. Therefore, intramolecular proton transfer reaction processes in excited state are much easier than those in ground state.

007173   Zhou W;Xu D F;Zhao A H;Li S S (School of Pharmacy, Shanghai Jiaotong Univ, Minhang, Shanghai 200240, P.R. China, Email: ssli@sjtu.edu.cn) : Mild and efficient semi-synthesis of shikonin leucoacetates. J Indian Chem Soc 2008, 85(1), 75-7.

A mild and efficient synthesis of shikonin triacetate is developed by acetylation of shikonin with anhydrous acetic anhydride in the presence of iodine as an extremely powerful catalyst under solvent-free condition in 94.5% yield, then a regioselective reduction of carbonyl of 1,4-naphthoquinone with sodium monoacetoxyborohydride and acetylation of shikonin triacetate can afford shikonin leucoacetates with the yield of 76.4%.

12 ref

007172   Yajurvedi D;Kumbhani S;Shashtri I;Baghmar M; Sharma P K (Chemistry Dep, J. N. V. Univ, Jodhpur-342 005, Email: drpkvs27@yahoo.com) : Kinetics and mechanism of the oxidation of DL-methiomine by quinolinium bromochromate. J Indian Chem Soc 2008, 85(4), 459-61.

The oxidation of methionine (Met) by quinolinium bromochromate (QBC) in dimethylsulphoxide (DMSO) leads to the formation of corresponding sulphoxide. The reaction is of first order with respect to each QBC and Met. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form : k_obs = a + b [H⁺]. The oxidation of methionine was studied in nineteen different organic solvents. The solvent effect was analyzed by Kamlet's and Swain's multiparametric equations. Solvent effect indicated the importance of the cation-solvating power of the solvent. A suitable mechanism has also been postulated.

3 tables, 14 ref

007171   Wen-long W;Jun-bo L;Xin Y;Hong-hong C;Yan-wei L (Chemistry and Chemical Engineering Dep, Taiyuan Univ of Technology, Taiyuan, Shanxi 030024, P.R. China, Email: weiwenlong@tyut.edu.cn) : Convenient synthesis of crystalline 4-ethyl-2,3-dioxopiperazine-l-deriv carboxamido-p-hydroxyphenylacetyl chloride using triphosgene. J Indian Chem Soc 2008, 85(3), 328-9.

The crystalline 4-ethyl-2,3-dioxopiperazine-l-carboxamido-p-hydroxyphenylacetyl chloride was prepared in 97.6% yield when triphosgene was reacted with D(-)-2-[(4-ethyl-2,3-dioxo-l-piperazineyl)-carbonylamino]-2-(4-hydroxy phenyl)acetic acid (HO-EPCP) in methylene dichloride at 0-5 °C in the presence of triethylaminc (TEA). This new method without using chlorinating agent such as phosgene, diphosgene, phosphorus oxychloride or oxalyl chloride enjoys a number of advantages in that the reaction is carried out under mild conditions and is clean.

1 table, 5 ref

007170   Viswanathamurthi P;Kavitha R;Muthukumar M (Chemistry Dep, Periyar Univ, Salem-636 011, Email: viswanathamurthi@yahoo.com) : Synthesis and characteristics of Ni<. J Indian Chem Soc 2008, 85(7), 735-8.

The reactions of nickel(II) and cobalt(II) complexes, [MCl₂(PPh₃)₂] (M = Ni or Co) with bidentate Schiff base ligands derived from acetylacetone or benzoylacetone with aniline, o-, m-nitroaniline have been carried out. The complexes were characterized by elemental analysis, spectral (IR, electronic) and cyclic voltammetric studies and are formulated as [MCl(PPh₃)(L)] (M = Ni or Co; L = bidentate Schiff base ligand). A square planar structure has been tentatively proposed for all the new complexes.

3 tables, 11 ref

007169   Varshney S;Singh M (NO, , H.I.G. 142, Phase A, Shastri Puram, Sikandra, Agra-282 007, Email: mukhtarsingh2003@rediffmail.com) : Densities, viscosities, viscosity deviations and excess thermodynamic properties of ternary liquid mixtures of ethylenediamine/propylenediamine + 1,4-dioxane + (benzene or + toluene or + carbon tetrachloride) and their constituent binaries at 303.15 K. J Indian Chem Soc 2008, 85(7), 699-710.

Densities and viscosities of ternary liquid mixtures of ethylenediamine and propylenediamine with 1,4-diox-ane, as the second common component, and benzene/toluene/carbon tetrachloride as the third component and their constituent binaries have been measured at 303.15 K. The viscosity deviations (Δη) and thermodynamic excess properties (V^E and ΔG^*E) have been determined and fitted to Cibulka's equation. The experimental values of Δη, V^E and ΔG^*E have been found to be in close agreement with the theoretical values predicted by Cibulka's equation. The nature and strength of molecular interactions between the mixing components of the ternary liquid mixtures are also discussed.

1 illus, 4 tables, 24 ref

007168   Tiwari R K;Rastogi N;Sethi R;Shukla S (NO, , 231/103-Ka, Bagh Macca, Khinni Tare, Raja Bazar, Lucknow-226 003) : Synthesis and antileishmanial activity of 1-aminomethyl-5-substituted-3-{4'-(3"-chlorobenzyloxy)-benzoylhydrazon e}-2-indolinones. J Indian Chem Soc 2008, 85(1), 85-8.

5-Substituted-3-{4'-(3"-chiorobenzyloxy)-benzoylhydrazono}-2-indolinon es (3-6) were synthesised by the condensation of 4-(3'-chlorobenzyloxy)-benzoylhydrazine (2) and 5-substituted isatins. Mannich reaction in the presence of formaldehyde and heterocyclic secondary amines on indolinones (3-6) furnished l-aminomethyl'-5-substituted-3-{4'-(3"-chlorobenzyloxy)-benzoylhydrazo no}-2-indolinones (7-22). The structures of the compounds have been established by means of correct elemental analysis and spectral data (IR, PMR and Mass). The compounds have been screened for their antileishmanial potential against Leishmania donovani.

1 table, 19 ref

007167   Thirunarayanan G (Chemistry Dep, Annamalai Univ, Annamalainagar-608 002, Email: drgtnarayanan@gmail.com) : Insect antifeedant potent chalcones. J Indian Chem Soc 2008, 85(4), 447-51.

Some halogen substituted 2-propen-1-ones were synthesized by solvent free eco-friendly method. They are characterized by physical constants, analytical and spectral data. Their antifeedant activity against caster semilooper and Achoea Janata L. has been studied. The chlorinated chalcones were found to be most effective.

3 tables, 16 ref

007166   Suleman;Susan Verghese P;Prasad F M (NO, , 1/11 Sindhi Colony, Ashok Nagar, Agra-282 002) : Ultrasonic study of vanadium myristate in liquor ammonia. J Indian Chem Soc 2008, 85(8), 852-6.

The ultrasonic velocity of vanadium myristate confirms that there is a significant interaction between the solute-solvent molecules in dilute solutions and the carboxylate molecules do not aggregate appreciably in dilute solutions. The value of Critical Micelle Concentration (CMC) for vanadium myristate is in agreement with those obtained from other physical parameters. The effects of concentration and chain length of soap on ultrasonic velocity and the various acoustic parameters (adiabatic compressibility, specific acoustic impedance, intermolecular free length, apparent molar compressibility, apparent volume, molar sound velocity, molar sound compressibility and solvation number) have been investigated.

1 illus, 1 table, 33 ref

007165   Srivastava S;Singh S;Srivastava S;Srivastava P (Chemical Laboratories, Feroze Gandhi College, Rae Bareli-229 001, Email: She_ila72@yahoo.com) : Rhodium(III) catalyzed oxidation of dextrose and maltose by acidic solution of sodium periodate : a kinetic study. J Indian Chem Soc 2008, 85(6), 647-9.

The kinetics of rhodium(III) catalyzed oxidation of dextrose and maltose by sodium periodate in acidic medium has been studied in the temperature range 30-45 °C. The reaction is carried out in the presence of mercuric acetate as a scavenger for iodide ion. The rate shows first order kinetics with respect to the oxidant, sodium periodate and Rh^III for both dextrose and maltose. A suitable mechanism in conformity with the kinetic observations has been proposed and the thermodynamic parameters computed.

3 tables, 3 ref

007164   Srivastava S D;Shukla D K (Synthetic Organic Chemistry Laboratory, Chemistry Dep, Dr. H. S. Gour Univ, Sagar-470 003, Email: dks_chem@yahoo.co.in) : Synthesis and biological significance of 2-aminobenzothiazole derivatives. J Indian Chem Soc 2008, 85(3), 306-9.

Several new 2-N-(substituted benzyledine)-imino-1,3-benzothiazole 1; 2-[2'-(substituted phenyl)-4'-oxo-1',3'-thiazolidine]-l,3-benzothiazole 2 and 2-[5'-(arylidene)-2'-substituted phenyl-4'-oxo-l',3'-thiazolidine]-l,3-benzothiazole 3 have been synthesized and evaluated for their antifungal activity against Aspergillus niger, Aspergillus flavus, Fusarium oxysporum and Trichoderma viride and antibacterial activity against Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus.

3 tables, 15 ref

007163   Srivastava A K;Srivastava A;Archna;Jaiswal M (QSAR Research Laboratory, Chemistry Dep, Allahabad Univ, Allahabad-211 002, Email: akanchha_au@rediffmail.com) : Role of physico-chemical parameters in quantitative structure-activity relationship based modeling of CYP26A1 inhibitory activity. J Indian Chem Soc 2008, 85(7), 721-7.

Quantitative Structure-Activity Relationship (QSAR) studies were performed on CYP26A1 inhibitory activity using physico-chemical parameters like Balaban centric index (BAC), mean Weiner index (WA), Balaban distance connectivity index (J), information theoretic index (Id), zero order (°χ), first order (¹χ) and second order (²χ) of molecular connectivity, polarizibility (Pz) and partition coefficient (log P) along with appropriate dummy parameter. The QSAR models were tested for their statistical significance and reliability by using leave one out cross validation method. Some significant models have been reported.

1 illus, 4 tables, 29 ref

007162   Srivastava A K;Pathak V K;Archana;Jaiswal M (QSAR Research Laboratory, Chemistry Dep, Allahabad Univ, Allahabad-211 002, Email: vinay_qsar@rediffmail.com) : QSAR based modeling of a new class of RNA polymerase inhibitors. J Indian Chem Soc 2008, 85(6), 627-31.

Quantitative structure-activity relationship studies were performed on a series of RNA-polyinerase inhibitors which show activity against Rifainpicin resistant Staphylococcus aureus. Physico-chemical parameters together with indicator variable, gave the best model having significant statistical features including cross-validated parameters. Pogliani factor Q and the results of LOO (leave one out) method confirm the reliability and predictability of the proposed models and it may concluded that larger and polar groups will favour the inhibitory activity (pIC₅₀).

1 illus, 4 tables, 13 ref

007161   Srivastava A K;Jaiswal M;Archana;Chaurasia S (Chemistry Dep, Allahabad Univ, Allahabad-211 002, Email: qsarlab_am@rediffmail.com) : QSAR of substituted N-benzyl piperidines in the GBR series. J Indian Chem Soc 2008, 85(8), 842-8.

Quantitative structure activity relationship (QSAR) studies on substituted piperidine in the GBR series have been made. Significant correlations were been obtained by multiparametric regression by using structural parameters with indicator parameters. The dopamine transporter (DAT) inhibitory activity of these compounds was found to increase with equalized electronegativity, hydrophobicity and bulk. The generated models were statistically validated using leave one out technique and cross validation methods.

1 illus, 5 tables, 15 ref

007160   Soni N;Tiwari V;Kumbhani S;Shastri I;Sharma V (Chemistry Dep, J. N. V. Univ, Jodhpur-342 005, Email: drpkvs27@yahoo.com) : Kinetics and mechanism of oxidation of aliphatic aldehydes by morpholinium chlorochromate. J Indian Chem Soc 2008, 85(8), 857-61.

Oxidation of six aliphatic aldehydes by morpholinium chlorochromate (MCC) in dimethyl sulfoxide (DMSO) leads to the formation of corresponding carboxylic acids. The reaction is first order each in MCC and the aldehyde. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form : k_obs = a + b[H⁺]. The oxidation of deuteriated acetaldehyde, MeCDO, exhibited a substantial primary kinetic isotope effect (k_H/k_D = 5.95 at 298 K). The oxidation of acetaldehyde has been studied in 19 different organic solvents. The solvent effect has been analysed using Taft's and Swain's multiparametric equations. The rate constants correlate well with Taft's σ* values and reaction constants are negative. A mechanism involving transfer of hydride ion has been suggested.

3 illus, 4 tables, 12 ref

007159   Sivasankaran Nair M;Ravi Samuel Raj C (Chemistry Dep, Manonmanium Sundaranar Univ, Abishekapatti, Tirunelveli-627 012, Email: msnairchem@rediffmail.com) : Computation studies on schiff base ligands and equilibrium studies on their metal complexes. J Indian Chem Soc 2008, 85(4), 443-6.

Schiff bases of furfural with L-threonine (thr) and L-glutamine (gln) were studied by quantum mechanical method using GAMESS program. Geometry of the Schiff bases was optimized by HF and MP2 methods. The Schiff bases are non-planar. Based on the Mulliken's charge density calculations, furan oxygen, imino nitrogen and carboxylato oxygen atoms were found to be the potential binding sites. Equilibrium studies of Co^II, Ni^II, Cu^II and Zn^II-furfural (A)-L-threonine (thr), L-tryptophane (trp) and L-glutamine (gln) (B) systems were done by batch wise titration method at 25 °C and ionic strength of 0.1 μ (KNO₃). All the systems have MAB, MAB₂ or MAB₂ types of Schiff base complexes. The results indicate that the Schiff base (AB) binds to the metal ions in terdentate manner through furan oxygen, imino nitrogen and carboxylato oxygen atoms.

1 illus, 2 tables, 16 ref

007158   Sivaraj K;Elango K P (Chemistry Dep, Gandhigram Rural Univ, Gandhigram-624 302, Email: drkpelango@rediffmail.com) : Synthesis, spectral characterization and electrochemical behavior of some cobalt(III) complexes of the type cis-β-[Co(trien)(RC₆H₄NH₂ )Cl]Cl₂. J Indian Chem Soc 2008, 85(4), 365-70.

Seven new cobalt(III) complexes of the type cis-β-[Co(trien)(RC₆H₄NH₂)Cl]Cl₂, where R = H, p-Me, p-OMe, p-Et, p-OEt, p-F and m-Me have been prepared and characterized by elemental analysis, UV-Vis, FT-IR and ¹H NMR spectral techniques. The results of the spectral studies reveal that these complexes posses a cis-β arrangement of ligands around the cobalt ion. Molar conductance measurements support the 1 : 2 natures of these complexes. TGA and DTA studies reveal that these complexes are thermally stable up to 175 °C. Cyclic voltammetric studies of these complexes and a fairly linear correlation (r = 0.93) of reduction potential data with the Hammett's substituent constants indicates that the electroreduction depends on the nature of the sixth ligand.

3 illus, 5 tables, 27 ref

007157   Sirvi S;Meena V K;Meena R C (Chemistry Dep, Jai Narain Vyas Univ, Jodhpur-342 005, Email: rcmeena007@rediffmail.com) : Studies on the photochemical interaction of fuchsin basic dye with triton X-100. J Indian Chem Soc 2008, 85(8), 825-9.

A new solarchemical cell consisting of Fuchsin Basic, a cationic triphenyl methane dye, and triethanol amine as reductant in solution of surfactant separated from a saturated aqueous solution of iodine by a pyrex sintered glass membrane, has been developed. The surfactants used was Triton X-100 (non-ionic). The results show that the photopotential and photocurrent of the cell is increased in Triton X-100 and decreased with the cell without surfactant. The photopotential and photocurrent of the cell were observed as 690 mV, 175 u,A respectively and power of the cell was 63.4 u,A/min. The possible mechanisms of the cell in the various surfactants are discussed.

2 illus, 25 ref

007156   Singh V;Chandra G;Mobin S M (Chemistry Dep, Indian Institute of Technology, Bombay, Mumbai-400 076, Email: vks@chem.iitb.ac.in) : Cycloaddition of 6-hydroxy-2,6-dimethylcyclohexa-2,4-dienone: a stereoselective entry into functionalized bicyclo[2.2.2]octanes and a novel 1,2-migration of methyl group. Indian J Chem-Sect B 2008, 47(12), 1886-91.

Cycloaddition of 6-hydroxy-2,6-dimethylcyclohexa-2,4-dienones with ethyl vinyl ether, butyl vinyl ether, vinyl acetate and vinyl phenyl sulphone leading to a stereoselective entry into bicyclo[2.2.2]octanes having quaternary methyl group is reported. A novel thermal 1,2-methyl migration has also been described.

3 illus, 8 ref

007155   Singh P;Khandelwal P;Hara N;Asai T;Fujimoto Y (Centre of Advanced Studies, Chemistry Dep, Rajasthan Univ, Jaipur-302 004, Email: pahupsingh@yahoo.co.uk) : Radermachol and naphthoquinone derivatives from Tecomella undulata: complete <. Indian J Chem-Sect B 2008, 47(12), 1865-70.

Petroleum ether extract of the heartwood of Tecomella undulata affords radermachol, an unusual rare pigment and 2-isopropenyInaphtho[2,3-b]furan-4,9-quinone along with lapachol, tecomaquinone-I, dehydro-α-lapachone, α-lapachone, β-Lapachone, cluytyl ferulate, stigmasterol and β-sitosterol. Radermachol and 2-isopropenylnaphtho [2,3-b]furan-4,9-quinone are being reported for the first time from genus Tecomella. Complete assignments of ¹H and ¹³C NMR signals of polyketide, radermachol 1, have been achieved by the ¹³C NMR chemical shift prediction using ab initio MO and DFT/GIAO methods in addition to 2D-NMR techniques.

1 illus, 2 tables, 24 ref

007154   Singh G;Khandelwal C L;Sharma P D (Chemistry Dep, Rajasthan Univ, Jaipur-302 004) : Kinetics and mechanism of oxidation of pyruvic acid by peroxomonophosphate in acid perchlorate medium. J Indian Chem Soc 2008, 85(6), 615-21.

Kinetics of oxidation of pyruvic acid by peroxomonophosphate (PMP) has been studied in a wider pH range. The stoichiometry corresponds to the reaction as represented by the eq. (1) CH₃COCO₂H + H₃PO₅ → CH₃CO₂H + H₃PO₄. The pattern of reactivity of peroxomonophosphate species has been delineated. A plausible reaction mechanism is suggested. The energy and entropy of activation were calculated to be (72 ± 7) kJ mol^-1 and (-40 ± 4) JK^{-1 mol-1 respectively.}

3 illus, 1 table, 19 ref

007153   Singh B;Kaur H (Chemistry Dep, Punjabi Univ, Patiala-147 002, Email: baljit_chemz@yahoo.co.in) : Electrochemical reactions at sacrificial electrodes. Part-XXIII : direct electrochemical synthesis of bismuth(III) alkoxides. J Indian Chem Soc 2008, 85(8), 849-51.

Bismuth(III) alkoxides have been synthesized by electrochemical reactions of methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-onanol, n-decanol at sacrificial bismuth anode and inert platinum cathode using tctrabutylammonium chloride as supporting electrolyte and acetonitrile as solvent. The solid products separated in the anode compartment have been isolated and characterized by elemental analysis and infrared spectral studies. Current efficiencies of these reactions are quite high.

1 table, 18 ref

007152   Singh A;Tripathi V S;Chattopadhyaya M C (Electrochemical Sensors Lab, Chemistry Dep, Allahabad Univ, Allahabad-211 002, Email: mcc46@rediffmail.com) : Atomic absorption spectrophotometric determination of tryptophan and cysteine. J Indian Chem Soc 2008, 85(6), 635-7.

A novel method for determination of cysteine and tryptophan using atomic absorption spectrophotometry has been developed in which these substances are allowed to react with methanol solution of iodine there by iodide ions are released quantitatively and the released iodide ions are allowed to react with excess amount of silver nitrate for formation of equivalent amount of silver iodide precipitate. The excess of silver ions were determined by atomic absorption spectrophotometry and from total amount of silver ions added, the concentration of liberated iodide ions was calculated. The equivalent amount of cysteine or tryptophan was then calculated. Values obtained using this method were found to be comparable with the values obtained by conductometric titration.

2 illus, 1 table, 21 ref

007151   Singh A;Pandey M B;Singh J P;Singh S (Medicinal Chemistry Dep, Institute of Medical Sciences, Banaras Hindu Univ, Varanasi-221 005, Email: meet2sarita@gmail.com) : Peptide alkaloids of Zizyphus rugosa. J Indian Chem Soc 2008, 85(6), 658-9.

Five cyclopeptide alkaloids, sativanine-C, mauritine-A, mauritine-D, amphibine-B and nummularince-K has been isolated from the bark of Zizyphus rugosa and their structures were established by spectral evidences. This is the first report of these compounds in Z, rugosa.

10 ref

007150   Sharma S;Sharma A (Post Graduate Dep of Chemistry, Govt. College, Kota-342 001, Email: sharda_ak@yahoo.co.in) : Solvent free synthesis of new-1-acetyl-3-(4-fluoronaphthyl)-5-subsituted aryl pyrazolines as spermicides. J Indian Chem Soc 2008, 85(7), 750-3.

Reports the solvent free synthesis of l-acetyl-3-(4-fluoronaphthyl)-5-substituted aryl pyrazolines by using simple and efficient Green Chemistry techniques (Grindstone method and microwave irradiation). These methods have been developed for the rapid solvent free synthesis of title compounds from corresponding chalcones and hydrazine hydrate or phenylhydrazine in acetic acid. Considerable increase in the reaction rates have been observed with better yields compared with sample prepared from conventional method. Structure of synthesized new compounds have been confirmed on the basis of spectral (IR, ¹H NMR) and analytical data. Representative compounds have been screened for their spermicidal activity in HF cattles and Murrah buffalo.

3 tables, 21 ref

007149   Sharma S P;Lahiri S C (Central Forensic Science Laboratory, , 30, Gorachand Road, Kolkata-700 014, Email: sprasadsharma@rediffmail.com) : Preparation of data base for the determination and estimation of high explosives and a comparative study of different methods of estimation of RDX. J Indian Chem Soc 2008, 85(3), 273-9.

Analysis of post explosion residues containing high explosive and quick disposal of cases require a suitable analytical data base in the laboratory for the rapid detection and estimation of explosives in the residues. GC-MS is found to be appropriate for the separation, detection and estimation of explosives and a suitable data base for the detection and estimation of high explosives is presented. RDX has been found to be one of the main constituents of the explosives. Depending on the availability of RDX in the post explosion residues, suitable analytical method is needed for its detection and estimation. A comparative study of the different methods of detection and quantitation of RDX using UV-Vis, FTIR, GC-MS, HPLC and HPTLC instruments has been made for proper selection of the analytical method. The range of detection and estimation of RDX is 100 μg - 1 ng or less depending on the method used. Two chromogenic agents tryptophan and chromotropic acid used for the detection of CH₂O and RDX (which decompose to 3CH₂O in presence of strong H₂SO₄) were examined for the quantitation of CH₂O and traces of RDX. Formaldehyde in presence of H₂SO₄ and traces of FcCl₃, solution reacts with tryptophan to form a red colored complex with absorption maximum at 451 nm. Simllarly, CH₂O (RDX) reacts with chromotropic acid in 16 N H₂SO₄ to form a blue-violet colored complex with an absorption maximum at 577 nm. However, CH₂O can be completely converted into the complex with large excess of tryptophan or chromotropic acid and the extinction coefficients of the complex are utilized for the quantitation of CH₂O or RDX. The stability constant of the complex at 298 K between CH₂O and chromotropic acid has been determined.

4 illus, 6 tables, 14 ref

007148   Sharma N;Thakur M;Meena;Kumar V;Bhat S S; Chaudhry S C (Chemistry Dep, Himachal Pradesh Univ, Summer Hill, Shimla-171 005, Email: neerajsharma_univ@yahoo.co.in) : Synthesis and characterization of organotin(IV) complexes of 2-phenylphenol. J Indian Chem Soc 2008, 85(7), 691-8.

The n-dibutyl and triphenyltin(IV) complexes of composition n-Bu₂SnCl_2-x(OAr)_x and Ph₃Sn(OAr) (where OAr = OC₆H₄-Ph-2; x = 1 and 2) have been synthesized in quantitative yields by the reaction of their respective chlorides, n-Bu₂SnCl₂ and Ph₃SnCl with trimethylsilyl derivative of 2-phenylphenol in carbon tetrachloride. On the other hand, the good yields of the complexes of composition Me₂SnCl_2-x(OAr)_x and n-Bu₃Sn(OAr) have been obtained from the reaction of Me₂SnCl₂ and n-Bu₃SnCl with 2-phenylphenol in the presence of Et₂NH in tetrahydrofuran. The characterization of the complexes has been accomplished by elemental analyses, molar conductance measurements, molecular weight determinations and IR, ¹H, ₁₃C, ¹¹⁹Sn NMR and mass spectral methods. The thermal behaviour of the complexes has been studied by TG-DTA techniques. The reactions of parent complexes with nitrogenous bases viz. imida-zole and benzimidazole have yielded 1 : 1 and 1 : 2 molecular adducts authenticated by physicochemical and IR spectral data.

3 tables, 18 ref

007147   Sharma J C;Bhardwaj S (Chemistry Dep, Maharana Pratap Govt. P. G. College, Chittorgarh-312 001, Email: sidsidsmart@yahoo.co.in) : Removal of copper(II) from water using SrWO₄ - a photocatalytic process. J Indian Chem Soc 2008, 85(4), 395-8.

Photocatalytic removal of copper(II) over semiconductor SrWO₄ was carried out. The progress of reaction was observed spectrophotometrically. The effect of variation of different parameters like pH, concentration of copper(II), amount of photocatalyst, light intensity etc. on the rate of reaction was observed. A tentative mechanism for this reaction has been proposed.

5 illus, 1 table, 10 ref

007146   Sharma C;Thadhaney B;Pemawat G;Talesara G L (Chemistry Dep, M.L. Sukhadia Univ, Udaipur-313 001, Email: gtalesara@yahoo.com) : Synthesis of some novel ethoxyphthalimide derivatives of pyrazolo[3,4-c]pyrazoles. Indian J Chem-Sect B 2008, 47(12), 1892-7.

The synthesis of 5-methyl-4-substituted benzylidcne-2,4-dihydro-3f/-pyrazoi-3-onc 3a-d is achieved by the condensation reaction of 5-methyl-2,4-dihydro-3H-pyrazol-3-one 1 with 4-substituted benzaldehydes 2a-d. Compound 1 is prepared by the cyclization reaction between ethylacetoacetate and hydrazine hydrate in absolute alcohol. Compounds 3a-d are converted into corresponding ethoxyphthalimide derivatives 5a-d by treatment with phthalimidoxyethyl bromide 4. -N-Ethoxyphthlimido-3-methyl-4-(4-substituted benzylidene)pyrazoi-5-ones 5a-d are reacted with thiosemicarbazide/NaOH and isoniazid/AcONa/AcOH separately to yield 6-N-ethoxyphthalimido-4-methyl-3-(4-substituted phenyl)-2-thiocarbamoyl-3,3o-dihydro pyrazolo[3,4-c]pyrazoles 6a-d and 6-A'-ethoxyphthalimido-2-isonicotinoyl-4-methyl-3-(4-substituted phenyl)-3,3a-dihydro pyrazolo[3,4-c]pyrazoles 7a-d respectively. Structures of the synthesized compounds have been elucidated by means of IR, ¹H NMR and mass spectral data.

1 table, 32 ref

007145   Sharda Sundaram S;Srivastava A K; Chattopadhyaya M C (Chemistry Dep, Ewing Christian College (An Autonomous College of Allahabad Univ), Allahabad, Uttar Pradesh, Email: sharda100@rediffmail.com) : Determination of dissociation constants of salicylic acids and stability constants of complexes of these ligands with copper(II), berylium(II) and iron(III) ions : correlation of dissociation and stability constants with molecular descriptors. J Indian Chem Soc 2008, 85(1), 108-10.

Salicylic acid and its various derivatives have anti-rheumatic and antifungal action on human body. Dissociation constants of salicylic acid, o-/m-/p-cresotic acids and sulphosalicylic acid and stability constants of complexes of these ligands with Cu^II, Be^II ions were determined pH metrically and Fe^III ion were determined spectrophotomctrically. A quantitative structure relationship of stability/dissociation constant of the compounds with molecular properties were considered, which include molecular weight, surface tension, index of refraction and density. The biological action of these compounds vary with the substituent present in the ring.

1 illus, 6 tables, 6 ref

007144   Shankarwar S G;Shankarwar A G;Chondhekar T K (Chemistry Dep, Dr. Babasaheb Ambedkar Marathawada Univ, Aurangabad-431 004) : Stability constant of ternary complexes of copper(II) involving schiff bases as primary ligands and amino acids as secondary ligands. J Indian Chem Soc 2008, 85(7), 739-41.

The formation constant of mixed ligand complexes of copper(II) with Schiff bases 1-(2'-hydroxyl benzamido)-2-phenyl azomethine (L₁) and 1-(2'-hydroxyl benzamido)-2-(2-methyl phenyl) azomethine (L₂) as primary ligands and glycine (R₁), DL-valine (R₂) as secondary ligands have been determined potentiometrically in 40% (v/v) THF-water mixture at 30 °C and ionic strength of 0.1 M NaClO₄. The protonation constants of free ligands and stability constant for ternary systems involving Schiff bases and amino acids were also determined under identical conditions. The pH titration data were analysed using the computer SCOGS programme. The relative stability of ternary complexes as compared to that of corresponding binary complexes has been quantitatively explained in terms of Δ log K, K_R, K_L and K_r values.

2 tables, 5 ref

007143   Shah A Y;Wadawale A;Sagoria V S;Jain V K; Sharma R;Nagar M;Bohra R (Chemistry Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, Email: jainvk@barc.gov.in) : Di- and tri-organogermanium carboxylates: synthesis, spectroscopy and structures of [Me₃Ge(O₂CC₉H₆N)] and [Et₂Ge(O₂CC₅H₄N)₂]. Indian J Chem-Sect A 2009, 48(3), 333-8.

Di- and tri-organogermanium carboxylates, [R₂Ge(O₂CAr)₂] and [R₃Ge(O₂CAr)] (R = Me, Et or Bu; Ar = C₅H₄N, C₉H₆N), have been synthesized by the reactions of the corresponding dialkyldichloro germane and trialkylchloro/bromo germane with an appropriate sodium salt of N-heterocyclic carboxylic acid, (C₅H₄N.COOH, C₉H₆N.COOH), in 1:2 and 1:1 molar ratio in anhydrous benzene. These compounds have been characterized by elemental analysis, IR and NMR (¹H and ¹³C{¹H}) spectroscopy. Molecular structures of [Me₃Ge(O₂CC₉H₆N)] and [Et₂Ge(O₂CC₅H₄N)₂] have been determined unambiguously by X-ray diffraction study. The former has a distorted tetrahedral configuration around germanium with monodentate carboxylate group, while the latter has distorted trigonal bipyramidal geometry.

007142   Sengupta S K;Pandey O P;Srivastava A K;Mishra M K;Tripathi C M (Chemistry Dep, DDU Gorakhpur Univ, Gorakhpur-273 009, Email: sengupta2002@yahoo.co.in) : Synthesis, spectral and antibacterial studies of bis(cyclopentadienyl)titanium(IV)/zirconium(IV) and mono(cyclopentadienyl)titanium(IV) complexes of antipyrine schiff bases. J Indian Chem Soc 2008, 85(3), 247-51.

The reactions of mono(cyclopentadienyl)titanium(iv) trichloride and bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloride with Schiff bases, derived by condensing 4-aminoantipyrine with benzaldehyde (L₁), furfuraldehyde (L₂), pyridine-4-carboxaldehyde (L₃) or salicylaldehyde (L₄H), have been studied in anhydrous tetrahydrofuran or dichloromethane and products of types [Cp₂M(L)Cl]CI, [CpTiCl₃(L)] (L = L₁, L₂ or L₃,); [Cp₂M(L₄)]Cl, [CpTiCl₂(L₄)], [CpTi(L₄)₂]Cl [M = Ti^IV or Zr^IV] have been isolated. Tentative structures are proposed for these complexes based upon elemental analyses, electrical conductance and spectral (electronic, IR, ¹H NMR and ¹³C NMR) data. Attempts have been made to establish a correlation between antibacterial activity and the structures of the products.

4 tables, 14 ref

007141   Sen S;Maity S K;Pradhan N C;Patwardhan A V (Chemical Engineering Dep, Indian Institute of Technology Kharagpur, Kharagpur-721 302, Email: ncp@che.iitkgp.ernet.in) : Utilization of hydrogen sulphide for the synthesis of dibenzyl sulphide: effects of process parameters on conversion and selectivity. Int J chem Sci 2007, 5(4), 1569-78.

Dibenzyl sulphide (DBS) was synthesized by the reaction between benzyl chloride and aqueous ammonium sulphide using tetrabutylammonium bromide (TBAB) as phase transfer catalyst (PTC). Benzyl mercaptan (BM) was identified in the reaction mixture as the secondary product. The selectivity of DBS, was maximized by changing various parameters such as stirring speed, temperature, catalyst loading, concentration of benzyl chloride and NH₃/H₂S mole ratio. The highest selectivity of DBS obtained was about 90% after 445 minutes of reaction with excess benzyl chloride at 333 K. Complete conversion of benzyl chloride could be achieved at the cost of very low selectivity of DBS and very high selectivity of BM. The apparent activation energy for the kinetically controlled reaction was found to be 174.4 kJ/mol.

7 illus, 8 ref

007140   Saha B;Chowlu C K;Karthik Reddy P;Ghoshal A K (Chemical Engineering Dep, Indian Institute of Technology Guwahati, Guwahati-781 039) : Effect of aluminium content in al-MCM-41 catalyst on decomposition of low density polyethylene (LDPE). Int J chem Sci 2007, 5(4), 1552-60.

Four AI-MCM-41 catalysts containing different amount of aluminium are prepared using N cetyle-N,N,N - trimethylammonium bromide (C₁₉H₄₂BrN) as template. The prepared catalysts an characterized and used to study the catalytic decomposition of waste LDPE samples. The highest BK surface area and pore volume are obtained from the highest Si/Al ratio containing AI-MCM-41 or AI-41 P(100) samples and the lowest BET surface area and pore volume are obtained for Si/Al ratio of 36.5 containing sol-gel Al-MCM-4l or AI-41-P(30) samples. Catalytic effect in terms of reduction in maximum decomposition temperature (Tm) on waste LDPE follows the sequence Al-41-P(15)>Al-41 P(30)>Al-41-P(60)>Al-41-P(100). Further experiments on product analysis are carried out for AI-41 P(30) catalyzed pyrolysis to learn the products formed during both thermal and catalytic pyrolysis of the plastic materials used in the study. The results show that mesoporous Al-41-P(30) produce large amount of heavier hydrocarbons in comparison to the noncatalytic decomposition.

5 illus, 2 tables, 20 ref