Complexes of Nile Red and b- or g-cyclodextrin: A semiempirical-density functional theory-molecular dynamics route
November 2011
The association of Nile Red (NR) with b-, and g-cyclodextrins (CDs) was analyzed by semiempirical parametric method 3 (PM3), density functional theory-Becke, three-parameter, Lee-Yang-Parr hybrid functional (DFT-B3LYP/6-31G), and molecular dynamics (MD) and Langevin dynamics (LD) calculations, including annealing and molecular mechanics (MM) geometry optimization. Our results suggest that inclusion complexes...
Syntheses and crystal structures of two o-phthalate based transition metal complexes
November 2011
We report the synthesis and the crystal structures of two complexes. The two metal complexes; (1) [Zn(bipy)2(HPht)](HPht)·H2O and (2) [Cu2(Pht)2(Bipy)2] ·4H2O (where Pht2― = dianion of o-phthalic acid, HPht― = anion of o-phthalic acid, Bipy = 2, 2′-bipyridine) have been synthesized and their crystal structures were determined by elemental analyses, IR and single crystal diffraction...
Simple and simultaneous spectrophotometric determination of Pd (II) in alloys using hydrazone compounds
November 2011
A highly selective, reproducible and rapid spectrophotometric method for the determination of palladium (II) is developed based on the reaction of Pd (II) with 2,4-dihydroxyl acetophenone-p- hydroxylbenzoylhydrazone [RPPHBH] in the pH range 5 to 6 which forms a stable pale green complex. The complex shows absorbance maximum at 375 nm at pH of 5.5. Beer’s law is obeyed in the range 1.06 to 8.51 µg/ml of...
Effect of additive for efficient combustion of cracked furnace oil
November 2011
Present communication deals with evaluation of various additives, formulations and chemicals that are either commercially available or synthesized in authors’ laboratory for cracked residual fuel oil. The objective of this study is to assess the suitability of these additives and chemical components with regard to sediment and deposit inhibiting characteristics and study the effect of the additives on actual fuel...
Emamectin benzoate residue analysis in ground and terrestrial field water in Lahore suburban area
November 2011
High performance liquid chromatography with diode array detector was used to determine the ememactin residue in ground water in Lahore suburban area. The samples were extracted with chloroform through solvent extraction by using a separating funnel. The chemicals used were chloroform, methanol (HPLC grade) and acetonitrile (HPLC grade). Mobile phase used was acetonitrile (98%) and methanol (2%). 10 samples were analyzed...
Chemical constituents and biological activities of the genus Zanthoxylum: A review
October 2011
Zanthoxylum known as “Timoor” is used as mouth fresh, tooth care, spice and in intoxicating of the fishes. The present study deals with documentation of isolated chemical constituents and biological activities of the genus Zanthoxylum. The chemical constituents and essential oil have been isolated and characterized by several analytical methods. Alkaloids and cumarins are the main constituents...
Synthesis of benzothiazoyl salicylate moieties
October 2011
Aminosalicylates are derivatives of the highly functionalized compound aminosalicylic acid. Benzothiazoyl salicylates were obtained in this work from the highly functionalized aminosalicylic acid by reacting ammonium thioureas as a nucleophile to aminosalicylates that were derived from aminosalicylic acid and bromine was used as the cyclising agent. Results obtained indicated that it was the brominated cyclised product...
Facile green synthesis of 2, 4-substituted -2, 3- dihydro -1, 5 Benzothiazepine derivatives as novel anticonvulsant and central nervous system (CNS) depressant agents
October 2011
The present work reports eco friendly synthesis of 2, 4-substituted -2, 3- dihydro -1,5-benzothiazepine derivatives as novel anticonvulsant and central nervous system (CNS)depressant agents having lesser side effects. Facile, one pot efficient, solvent free microwave-assisted green synthesis of 1, 5-benzothiazepine derivatives by cyclo- condensation of 2-aminothiophenol with 1, 3-substituted-prop-2-en-1-one (2a-h)...
Sodium nano-particle effects on montmorillinite structure
October 2011
The main aim of the work is to study the expansion of the inter-layers clay to see what will happen to the mechanical properties of clays. The expansion of clay layers with sodium nano- particles makes for the exfoliation and dispersion of the crystal in fine particles in the clay positions. Patterns obtained by X-ray diffraction (XRD) of nano montmorillinite (MMT) illustrate that its shape is irregular and the range of...
Structural study of complex lipids present in soils: Characterization of monocarboxylic acids resulting from polar lipids fraction alkaline hydrolysis
October 2011
In acid soils such as turf, the biological activity is reduced, so lipids tend to accumulate. Those lipids are made of two fractions: one fraction, named “simple lipids”, directly analyzable, and the other, named “polar lipids” or “complex lipids”. The structure and origin of these “polar lipids” had been investigated using chemical degradation methods. The degradation...
Reverse-flow-injection analysis (FIA) for the determination of Vitamin C in pharmaceutical formulation with chemiluminescence detection
October 2011
A reverse flow injection chemiluminescence (CL) method for the fast and simple determination of vitamin C has been developed. The CL light observed after luminal-H2O2 aqueous solution was added to the on-line formed Br2 solution from mixing of HBr and KBrO3 solutions was inhibited in the presence of Vitamin C. Based on these facts, a determination method of Vitamin c was developed. In order to...
Potential of nano crystalline hydroxyapatite for lead (II) removal from aqueous solutions: Thermodynamic and adsorption isotherm study
October 2011
The potential of the synthesized nano hydroxyapatite to remove Pb (II) from aqueous solutions was investigated in batch reactor under different experimental conditions. The study also investigates the effects of process parameters such as initial concentration of Pb (II) ion, temperature and adsorbent mass. Various thermodynamic parameters, such as G°, H° and S° have been calculated. The...
Effects of solvent on the UV-visible absorption spectra of acenaphtho(1,2-b) quinoxaline and acenaphtho(1,2-b)benzo(g)quinoxaline
October 2011
The effects of solvent on the electronic absorption spectra has been used to investigate the structural and molecular properties of acenaphtho(1,2-b)quinoxaline and acenaphtho(1,2-b) benzo(g)quinoxaline. The structures of the compounds have been established by UV-visible spectrophotometer. The spectra behaviours in terms of dipole moments in the ground and excited states have been interpreted and related to the...
Comparing the conducting properties of benzobispyrrole-derived and benzobisthiazoles-derived squaraines
October 2011
Smaller or vanishing value of semiconductor energy band-gap (Eg ) is a good factor that determines the conductivity of semiconductor polymers and it has high correlation with the intrinsic electronic, optical and magnetic properties of materials. Squaraine dyes because of their unique optical properties have been shown to be an ideal candidate as one of the building blocks organic dyes with physical property of low HOMO...
“Photochemical synthesis and spectroscopic studies of 3, 5-alkyl/aryl substituted-tetrahydro-2H-1,3,5-thiadiazine-2-thione and their complexes with M(CO)4(η2:2- NBD) [M = Cr, Mo and W] as M(CO)4 transfer reagentâ€
October 2011
Fifteen new complexes, [M(CO)4(L)2] [M=Cr; Mo; W]; [L= met-DTTT; et-DTTT; n-pr-DTTT; ph-DTTT and benz-DTTT] have been synthesized by the photochemical exchange reaction of [(η2:2- NBD)M(CO)4] (M= Cr, Mo and W) with 3,5-dimethyl-tetrahydro-2H-1,3,5-thiadiazine-2-thione (met-DTTT), 3,5-diethyl-tetrahydro-2H-1,3,5-thiadiazine-2-thione (eth-DTTT), 3,5-di-n-propyl-tetrahydro-2H-1,3,5-thiadiazine-2-thione...
Hydrogenation of 2H-azirine by aluminium lithium hydride over palladium catalyst
September 2011
The hydrogenation of 2H-azirine by the aluminium lithium hydride (AlLiH4) in the presence of palladium used like catalyst, was studied by Hartree Fock method. For the modelling of reaction, the catalyst was represented by one atom of palladium; we took one molecule of 2H-azirine for two molecules of aluminium lithium hydride. The reaction gave a saturated derivative of 2H-azirine (C2H3N) called aziridine (C2H5N). On the...
Comparison of low temperature coal tar solvent extractible and bound biomarker distribution for correlation studies
September 2011
Solvent extractible and bound biomarker profile for low temperature coal tar were compared using the biomarker ratios obtained from the selective ion resolution for pristane, phytane, n-C17 and hopanesratios of GC-MS results, with a view to ascertaining whether or not the data for asphaltene-derived biomarker can be used for effective correlation studies, and if serious alterations arising from biodegradation and...
Comparison of aromatics released via hydropyrolysis with their solvent extractable counterpart for biodegraded Nigeria crude oil
September 2011
The molecular profiles of aromatics generated through hydropyrolysis with the free (maltene) counterpart were compared, with a view to assessing the effectiveness of using molecular information for the aromatics bound in asphaltene matrix for polycyclic aromatic hydrocarbon source apportionment studies. The results obtained from gas chromatograph-mass spectrometry (GC-MS) total and selected ion molecular profiles of...
Effect of beta irradiation on plasticized polyvinyl chloride
September 2011
Various polyvinyl chloride (PVC) formulations were compounded with two types of plasticizers- diocthylphthalate (DOP) and epoxidized rubber seed oil (ERSO). The samples were subjected to beta irradiation at a rate of 2.4 mGy/h to total dose of 14.4mGy. The mechanical properties and the plasticizer permanence such as leaching and migration of plasticizers from the various samples were evaluated. The tensile strength...
The textural property of chromium pillared clay
September 2011
Hydroxy-chromium beidellite is of interest for use in catalysis and as adsorbents. The micro porosity of the materials differing in pillar density has been explored. Nitrogen adsorption data obtained at very low relative pressures were used. This paper determines the influence of the OH-Cr species on the structure and texture of modified dioctahedral smectites (beidellite). Minerals varying in cation exchange capacity...
Thermal degradation of poly(vinyl chloride) in the presence of Ximenia americana and Balanites aegyptiaca seed oils
September 2011
Ximenia americana seed oil (XSO) and Balanites aegyptiaca seed oil (BSO) were soxhlet extracted and characterized. The iodine values were 158.3 and 102.6 gI2 100 g-1 for XSO and BSO, respectively. The oxirane content for the epoxidized oil derivatives, EXSO and EBSO, were 4.9 and 4.1%, respectively. Kinetic studies of thermal degradation of poly (vinyl chloride), (PVC) in the...
Anthocyanidin 3-galactosides from flowers of Abrus canescens Bak
September 2011
Three anthocyanins, the 3-galactoside of delphinidin (1) (8.5 %), petunidin (2) (9.2 %) and malvidin (3) (73.8 %) were isolated from the deep red-purple flowers of Abrus canescensby a combination of chromatographic techniques. Their structures were elucidated by on-line diode array detection chromatography and homo- and hetero-nuclear magnetic resonance (NMR) techniques. Key words: Abrus...
Thermodynamics of the adsorption of palmitate and laurate soaps onto some metal ore surfaces in aqueous media
September 2011
The thermodynamics of the adsorption of sodium-palmitate and sodium-laurate onto galena, hematite and cassiterite surfaces in aqueous media has been studied. The adsorption capacities of the soaps (adsorbates) were determined and the Langmuir, Freundlich and Temkin isotherm models were used to fit the experimental data. The Langmuir isotherm model was the best to describe the adsorption process with the highest...
Induced autocatalytic preparation of gold nanostructure
September 2011
The present study found that gold nanoparticles with nanosizes below 100 nm can be synthesized by a wet-chemical route, carried out by induced autocatalytic method. The successive liking of the neighboring nanoparticles seeds by benzenedimethanethiol (BDMT) followed by the induced reduction of Au (III) ions leads to the formation of well defined nanostructure assembly. The size and shape of gold nanoparticles were...
Ab-initio study of the ground state structure and properties of Fe+2 (thymine)2 (H2O)2 complex
September 2011
Hartree-Fock calculations with 6-31G (d) basis set have been done in the gas phase on Fe+2 (thymine)2 (H2O)2 complex with complete geometry optimization. Stable structure for the complex has been found. Single point water phase calculation (PCM) has also been done which shows that the complex is more stable in water implying its physiological action for the removal of excess hazardous Fe+2 from the...
Inhibitive action of hexadecyltrimethylammonium bromide (HDTAB) on aluminium alloy (AA3003) corrosion in hydrochloric acid medium
September 2011
The inhibitive effect of hexadecyltrimethylammonium bromide (HDTAB) on the corrosion of aluminium alloy (AA3003) in 1 M hydrochloric acid medium was studied by weight loss method in relation to the temperature (25 to 55°C) and inhibitor concentration range 5.10-4 to 10-2 M. This study showed that the inhibitor adsorbs on aluminium alloy (AA 3003) according to the modified Langmuir adsorption isotherm; the...
Catalyzed pyrolysis of plastics: A thermogravimetric study
September 2011
Thermal or catalytic pyrolysis processes have attracted much attention for the conversion of plastic wastes to a mixture of their basic hydrocarbons, which can be valuable either as fuels or as raw chemicals. The effect of different catalysts on the thermal degradation of propylene (PP) has been studied by thermogravimetric analysis (TGA). TGA experiments were used to compare the activity of different catalysts towards...
Effect of acid hydrolysis on the physicochemical properties of cola starch
September 2011
Cola starch from Cola nitida (rubra) was isolated using 1% (w/v) sodium metabisulphite solution and was treated with 0.1 and 0.2 M HCl solution differently at 80 and 100°C, pH (6 to 7.9) and reaction time (30 min to 3 h). The physicochemical and functional properties of the hydrolyzed starch were studied. The hydrolysis reaction presented important changes in the pasting, thermal transition and morphology...
The corrosion behavior of sputter-deposited ternary W–Zr–(15–18)Cr alloys in 12 M HCl
August 2011
New series of amorphous or/and nanocrystalline W–Zr–(15–18)Cr alloys are successfully prepared by direct current (DC) magnetron sputtering. The role of alloy-constituting elements on the corrosion behavior of the W–Zr–(15–18)Cr alloys is studied by corrosion tests and electrochemical measurements in 12 M HCl solution open to air at 30°C. All the examined sputter-deposited...
Monitoring metals pollution using water and sediments collected from Ebute Ogbo river catchments, Ojo, Lagos, Nigeria
August 2011
The levels of Cu, Pb, Cd, Zn and Ca in water and sediments collected from the Ebute Ogbo River catchments, Ojo, Lagos, Nigeria were determined by flame atomic absorption spectrometry. The samples were collected in year 2008 and 2009. The results obtained showed a decrease in the Cd, Pb and Ca levels in water samples for 2009 compared to year 2008. However, Cu and Zn levels were in the increase. Nevertheless, metals...
Some hydrazone derivatives as corrosion inhibitors for iron in 3.5% H3PO4 solution
August 2011
The inhibition of corrosion of pure iron in 3.5% H3PO4 by some hydrazone derivatives has been investigated by weight loss and galvanostatic polarization techniques. The inhibition efficiency was increased by increasing inhibitor concentration and decreased by rise in temperature. Polarization studied revealed that these compounds behave as mixed-type inhibitors. The inhibition action of hydrazone derivatives was...
Tannins and other phytochemical of the Samanaea saman pods and their antimicrobial activities
August 2011
Preliminary phytochemical screening of n-hexane extract of Samanea saman(Mimosaceae) pods revealed a moderate presence of the major secondary metabolites. Extraction and concentration of the S. saman pods with 70% aqueous acetone yielded the characteristic reddish brown solid tannins. Qualitative and quantitative analysis showed that the tannins were of condensed (catechol) type and about 7.9% (0.079...
Removal of Pb (II) in aqueous solution using acid activated carbons prepared from cola edulis shell (Alocaceae), pentaclethra macrophylla husk (Mimosaceae) and aucoumea klaineana sawdust (Burseraceae)
August 2011
The present research was undertaken to study the potential efficiency as adsorbents of three acid activated carbons, prepared from plant biomass of colas edulis shell (CAH), pentaclethra macrophylla husk (GAH) and aucoumea klainenea sawdust (QAH), for the removal of Pb (II) ions from aqueous solution, by the means of batch technique. The study was managed using pH, concentration of lead solution, adsorption...
Spectrophotometric and thermodynamic studies of the charge transfer complexation of nitroimidazoles with chloranilic acid following metal hydride reduction
August 2011
The spectrophotometric and thermodynamic properties of the charge-transfer (CT) complexation formed between reduced nitroimidazoles and chloranilic acid has been carried out. The possibility of room temperature reduction of metronidazole and tinidazole via hydride transfer using LiBH4 and NaBH4 was examined and the physicochemical properties of the resulting complex of the reduced nitroimidazoles...
Comparative study of corrosion inhibition of aluminium alloy of type AA3003 in acidic and alkaline media by Euphorbia hirta extract
August 2011
The inhibitive effect of leaf extract of Euphorbia hirta on aluminium corrosion in HCl and NaOH solutions were studied using gravimetric technique at 30 and 60°C. Results obtained showed that the leaf extract functioned as effective and excellent inhibitors in the acidic and alkaline media. Also, the leaf extract suppressed the corrosion reaction in both media. Inhibition efficiency of the extract was...
Excess parameters of binary and ternary mixtures of {1-Butanol + hexylamine + n-heptane} at different temperatures and comparison with the Flory theory
July 2011
In this work, we calculated (thermal expansion coefficients), (excess thermal expansion coefficients) and (isothermal coefficient of pressure excess molar enthalpy) for the binary and ternary mixtures of {1-butanol + hexylamine + n-heptane} from experimental densities (Djordjevic et al., 2010) at (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15) K. The trends...
A high yield synthesis of phenytoin and related compounds using microwave activation
July 2011
A reaction system is described to synthesize phenytoin, a major antiepileptic drug, and structurally related compounds using a two-step approach. The first step involves the treatment of a benzil derivative by thiourea in dimethylsulfoxide (DMSO) in aqueous KOH under microwave activation. The resulting 2-thiohydantoin was then oxidized to the corresponding hydantoin using perhydrol in dimethylformamide (DMF) in acetic...
Stabilization of manganese (Mn)-induced peroxide decomposition
July 2011
Various ways were explored to reduce Mn-induced peroxide decomposition under conditions similar to industrial bleaching of mechanical pulps. It was found that hydrogen peroxide is more stable if Mn (II) or (III) are stabilized prior to peroxide addition. Sodium silicate/magnesium sulfate solution stabilized hydrogen peroxide in the presence of both Mn(II) and Mn(III), while diethylenetriamine pentaacetic acid (DTPA)...
Identification of 3- deoxyanthocyanins from red sorghum (Sorghum bicolor) bran and its biological properties
July 2011
Anthocyanins known as potent antioxidant provides attractive colours and used as an ingredient in food systems. This study aims to evaluate a potential anthocyanin extraction method from red sorghum bran and to investigate its antioxidant and cytotoxic properties. The anthocyanin content was found to be higher in acidified methanol and on separation was identified as apigeninidin and leuteolinidin, which obviously could...
Classification of lubricants using neutron slowing-down technique
July 2011
The neutron slowing down technique employing a facility based on a 1 Ci 241Am-Be neutron source base and 3He neutron detector has been used to classify lubricants. The facility utilizes the fast neutron slowing down technique in which the intensity of reflected thermalized neutrons is proportional to the hydrogen content of the sample exposed to it. A popular market product of different grades was analyzed in...
Effect of presence of free fatty acids on the drying of oil/drying catalysts mixtures
July 2011
Free fatty acids are usually generated spontaneously in oils either by action of enzymes inadvertently entrained during storage or mineral acids inherited from the refining process. The study investigated the effect of the presence of excess fatty acids on the drying/curing behaviour of drying oil admixed with drying catalysts. The oxygen absorption behaviours of Linseed oil (LSO) and rubber seed oil (RSO) on one hand,...
Copolymerization of methylol urea with ethylol urea resin for emulsion paint formulation
July 2011
In this work, copolymerization of urea formaldehyde (UF) and urea acetaldehyde (UA) was successfully carried out. Some physical properties such as gel time, viscosity, density, melting point, moisture uptake, refractive index and formaldehyde emission level were evaluated. The IR analysis of spectra from the pure amino resins and their copolymer (UF + UA) showed chemical interaction between urea formaldehyde and urea...
Convergent preparation of 2-phenylethanol
June 2011
The convergent synthesis of 2-phenylethanol was executed with bromination of benzene in the presence of pyridine to give bromobenzene which was reacted with magnesium metal to give phenylmagnesium bromide. Ethene was generated from ethanol and converted to 1,2-dibromoethane which in turn was reacted with the Grignard in an inverse manner to give 2-phenylbromoethane. Reaction of 2-phenylbromoethane and aqueous sodium...
Fatty acid profiles of the eggs and juvenile muscle of Nile perch (Lates niloticus, L. 1758) caught from Lake Victoria, Uganda
June 2011
Fatty acid profiling of the eggs and muscle of Lates niloticus juveniles was carried out, revealing the presence of two types of cholesterol and over twenty fatty acids. The total saturated fatty acid, total monounsaturated acid and the total polyunsaturated fatty acid compositions in the various samples lay in the ranges 13.39 to 41.81, 19.41 to 42.98 and 22.17 to 43.63%, respectively. There was a detection of an...
NMR and fluororescence enhancement effect studies of ternary inclusion complexes among naphthalenediamines-triethylene tetramine modified ï¢-cyclodextrin-lanthanide metal ions
June 2011
The 6-OH group of b-cyclodextrin (b-CD) was modified by triethylene tetramine. The modified host molecule successfully complexes 1,5-naphthalenediamine and 1,8-naphthalenediamine, respectively, in the presence of lanthanide metal ions (Y3+, Yb3+, Nd3+, Sm3+). As a result, eight ternary inclusion complexes (host-guest-metal) were formed, which were characterized via 1H nuclear magnetic resonance (NMR) technique. The...
Synthesis and characterization of three new benzylidene acetohydrazide copper (ІІ) complexes
June 2011
The synthesis and characterization of three complexes with copper (II) are described. The reaction between Cu(NO3)2.3H2O with bis[(E)-N'-(3-nitrobenzylidene) acetohydrazide], (NBAH) and bis[(E)-N'(4-methylbenzylidene) acetohydrazide], (MBAH) and bis[(E)-N'-(2,4-dichlorobenzylidene)acetohydrazide], (DBAH) produced three new ionic complexes. One of them is bis[(E)-N'-(3-nitrobenzylidene)...
A study on the solid phase extraction of CO(II)-IIDE chelate with C18 disk and its application to the determination of trace cobalt
June 2011
A sensitive, selective and rapid method has been developed for the determination of µg l-1 level of cobalt based on the rapid reaction of cobalt(II) with isopropyl 2-[(isopropoxy carbothioyl) disulfanyl] ethanethioate chelate (IIDE) and the solid phase extraction (SPE) of the colored chelate with Waters Porapak Sep-Park C18 disk. The isopropyl 2-[(isopropoxy carbothioyl) disulfanyl]ethanethioate chelate can...
Analysis of gas-chromatographic method for the determination of ethanol in an 18-F-fluorodeoxyglucose (FDG-18) solution
June 2011
A gas chromatographic method for determination of ethanol in an fluorodeoxyglucose (FDG)-18 solution was developed. The pre-validation tests were made to test some parameters. Three samples in the concentration of 400, 4000 and 7200 ppm, respectively were analyzed using the novel methodology. The results of the technique were not good. Although the method seems to be capable to identify ethanol in solution, the...
Antimicrobial and phytochemical activity of methanolic extract and its fractions of Jatropha curcas Linn. (Eurphorbiaceae) stem bark
May 2011
The stem bark of Jatropha curcas Linn (Euphorbiaceae) widely used in ethno medicine was studied. The methanolic extract (ME) and methanolic extract fractions (MEF) namely: chloroform fraction (CF), ethyl acetate fraction (EAF) and methanol fraction (MF) of J. curcas were subjected to antimicrobial evaluation and phytochemical screening. Results showed that saponins and steroids were present...
Synthesis and antibacterial activity of metal complexes of barbituric acid
May 2011
Cobalt (II), copper (II), iron (III), manganese (II) and nickel (II) complexes of barbituric acid were synthesized and characterized by infrared and ultraviolet spectroscopy. The ligand and the complexes have been screened for in vitro antibacterial activity against a range of Gram-positive and Gram-negative bacteria (Bacillus authracis, Bacillus cereus, Bacillus stearothemophilus, Bacilis subtilis,...
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