Asian Journal of Chemistry

1639-1642

Authors: Tan Phat Dao , Thien Hien Tran , Duy Trinh Nguyen, Duy Chinh Nguyen , Dai Hai Nguyen, Nhan Thi Hong Le, Do Trung Sy , Nguyen Thi Thanh Huong and Bui Le Minh*

Pomelo leaves oil has many applications regarding hair nourishment and stimulation. Recently, new methods of extracting essential oil used have been increasingly developed to replace traditional methods. In this research, maximization of essential oils yield from Citrus grandis was studied by the combination of microwave assisted hydro-distillation (MAHD) and response surface methodology (RSM). We found that the maximum essential oil yield was 0.3197 % with 91.3 % desirability corresponding to factors such as material and water ratiosof 3.04:1, extraction time at 62.76 min and microwave power of 482.17 W. ANOVA analysis for quadratic model also gives favourable outcome including the high determination coefficient (R2 = 0.9443), significant F-value and p-value of coefficients. All these values indicate that this model is significant between experimental and predicted variables.

1649-1652

Authors: B.S. Theerthavathy , Shaukath Ara Khanum and S. Ravi Kiran*

Germacrene D an important sesquiterpenoid has been extracted from leaves of Zanthoxylum ovalifoilum and high performance thin-layer chromatographic method has been developed for its simultaneous identification and determination. The compound was extracted by cold extraction and separated and identified on a AgNO3 impregnated silica gel 60 F254 HPTLC plates with dichloromethane:acetone (9.8:0.2 v/v) as mobile phase. The quantification of geremcare D was carried out by densitometry scanning performed at λ = 254 nm by reflectance scanning. This facilitated a well-resolved band for the compound with a Rf value of 0.46 ± 0.01. Linear regression concentration analysis data for mean calibration plots showed good linear relationship in the range of 1000-10000 ng/mL, with a correlation coefficient, slope and intercept of 0.9985 ± 0.0004, 21.62 ± 0.435 and 3308.87 ± 10.24, respectively. The minimum amount of germacrene D that could be authentically detected (LOD) and quantified (LOQ) were determined and found to be 212.07 and 521.23 ng/spot, respectively. The method was validated by considering the parameters linearity, precision, accuracy, specificity and robustness wherein, it is evident from the results that the proposed method was simple, safe and reliable.

1661-1666

Authors: G. Krishnamoorthi and R. Uvarani*

A relative study on pure L-alanine alaninium nitrate (LAAN) single crystals and doped with lanthanum oxide, urea and glycine were developed from fluid solution by slow evaporation strategy at room temperature. X-ray diffraction result reveals that LAAN crystallites with system with space bunch P21 and cell parameters a = 7.836 Å, b = 5.428 Å, c = 12.809 Å and β = 94.25°. These parameters were marginally changes for doped crystals compared to pure LAAN crystal. The UV results recommend that the great transmission property of the doped LAAN crystal within the whole visible region guarantees its reasonableness for second harmonic generation applications. The presence of dopants within the LAAN crystal was further affirmed through ICP studies. The functional groups were analyzed through Fourier change infrared spectra investigation. The microhardness and dielectric study at 100 Hz was found to be broadly higher than that of pristine LAAN. The AC conductivity was found to extend after doping due to the induced defects in crystal lattice. The grown crystals were also subjected to second harmonic generation efficiency tests and it was found to be La2O3 doped LAAN crystal is 2.8 times greater than that of potassium dihydrogen phosphate (KDP).

1675-1682

Authors: D.O. Sulistiono, E. Santoso and R. Ediati*

Impregnation of mesoporous silica MCM-41 on metal organic framework type HKUST-1 or often called CuBTC (BTC = 1,3,5-benzenetricarboxylate) has been successfully carried out by solvothermal methods in a solvent mixture of water, ethanol and N,N-dimethylformamide (DMF). The XRD patterns of the obtained solids showed that MCM-41/HKUST-1 composites had the same crystalline phase as pure as HKUST-1. SEM images revealed that the impregnation of the mesoporous silica to HKUST-1 did not alter the surface morphology of the original HKUST-1, which had octahedral shapes. In addition, the thermal stability of the MCM-41/HKUST-1 composites reached 302 °C, increased by 292 °C in comparison to the HKUST-1, even though the impregnation process resulted in a decreased in the specific surface area of the composites. Furthermore, MCM-41/HKUST-1 composites showed outstanding performance as adsorbent of methylene blue and Congo red in aqueous solutions. Results of adsorption studies showed that a pseudo-second order kinetics and Langmuir isotherm were observed for both types of dyes.

1688-1692

Authors: Milap G. Nayak*, and Amish P. Vyas

Microwave-assisted transesterification due to drastic reduction in reaction time when compared with conventional method gain the research attention. Pesent study explores the kinetic and thermodynamic study of microwave-assisted transesterification of non-edible papaya oil. The experiments were performed using pre-optimized process parameters having 9:1 molar ratio of methanol to oil, 1 wt. % NaOH catalyst. The experiments carried out in commercial microwave reactor with infrared temperature controller. Kinetic study of microwave-assisted palm oil methyl ester (POME) conversion was carried out by varying temperature from 50 to 65 ºC with an increment of 5 ºC. Kinetic study revealed that microwave-assisted homogeneous alkali-catalyzed transesterification follows first order having lower activation energy 27.86 KJ mol-1. Also, higher frequency factor 14764 min-1 and rate constant 0.6703 min-1 at 60 ºC revealed the non-thermal and thermal effect of the microwave. Other thermodynamic properties such as ∆G, ∆H and ∆S were found out to be 94.48 KJ/mol, 24.87 KJ/mol and -0.209 KJ/mol K, respectively, which show that reaction is non-spontaneous, endothermic and endergonic in nature.

1704-1708

Authors: Sunil Kulkarni

In the present investigations, activated sludge is used for removal of chromium in batch and continuous mode. It was observed that the sorption process followed Langmuir isotherm better than Freundlich isotherm (R2 = 0.95). The Freudlich model with R2 value above 0.9 suggests that the sorptive removal may involve physical and chemical adsorption with some multilayer sorption. Chromium uptake followed second order kinetics. The maximum adsorption capacity qe was observed to be 208.33 mg/g. The breakeven time and exhaustion time were determined for continuous operation. The non-availability of adsorbate at low flow rates play important role in delaying the break point time. Sludge age and initial concentration also affect the removal of chromium. The data follows the Thomas model with R2 value more than 0.9.

1719-1723

Authors: Nguyen Thi Thanh Thuy*, Le Duc Anh , Nguyen Huu Tri , Cu Van Hoang and Nguyen Anh Nhut

The PEG-coated iron oxide nanoparticles (Fe3O4 NPs-PEG) was synthesized by coprecipitation and ultrasonication method. X-ray diffraction results exhibited that the average size of Fe3O4 NPs-PEG was 19.10 nm, which was further confirmed in TEM imaging. In addition, sonication time and curcumin concentration were studied to evaluate the efficiency of loading curcumin onto Fe3O4 NPs-PEG. Further, statistical optimization using response surface methodology (RSM) has shown curcumin concentration (0,01% w/v) and sonication time (21 min) for maximal curcumin loading (0.37 mg/g). Along with the magnetization studies, the immobilization of curcumin onto the Fe3O4 NPs-PEG was characterized by UV, FTIR and SEM. The results showed that the curcumin loaded PEG coated iron oxide nanoparticles could potentially be used for magnetically target drug delivery

1729-1732

Authors: S. Vijayalakshmi , E. Kumar *, and S.C. Vella Durai

Zirconium dioxide nanoparticles have been synthesized by microwave assisted solution method. The prepared nanoparticle have been characterized by powder X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet- diffuse reflectance spectra, thermo gravimetric-differential thermal analysis and also evaluated for their antibacterial activity against bacterial strains. XRD pattern showed the prepared ZrO2 nanoparticles having monoclinic structure which shows the average crystalline size around 20 nm. SEM image showed the particles are spherical shape with agglomeration due to the intermolecular attraction for small particle size. From the UV-DRS, the energy band gap has found to be 4.9 eV. The results of antibacterial activity showed that the nanocrystalline zirconium dioxide had an important inhibitory activity against Pseudomonas arginosa. Photocatalytic degradation of methylene blue dye in the presence of ZrO2 nanoparticle under sunlight has been investigated at various times. The 75 % of methylene blue dye has been degraded at 140 min of sunlight irradiation. The photocatalytic activity of catalyst has been high for 40 mg/50 mL sample concentration.

1737-1747

Authors: V. Arjunan * , S. Senthilkumari and S. Mohan

The geometry of 3-trifluoromethylphenylchloroformate (FMPCF) was optimized with B3LYP method using 6–311++G** and cc–pVTZ basis sets. The molecular structural parameters and thermodynamic properties of the compound have been determined. The vibrational frequencies of the fundamental modes of the compound have been precisely assigned, analyzed and the theoretical results were compared with the experimental data. The energies of important molecular orbitals of the compound are also evaluated from DFT method. The Frontier orbital energy gap (ELUMO–EHOMO) is found to be 6.2143 eV. The extreme limits of the electrostatic potential is +8.301e × 10–3 to –8.301e × 10–3 while the total electron density spreads between +3.835e × 10–2 to –3.835e × 10–2. 1 H NMR and 13C NMR chemical shifts are measured and compared with their gauge independent atomic orbital (GIAO) calculated values. The n(O7) →π*(C13–O14) and π(C1–C6) →π*(C2–C3) transitions are best stablized with 48.40 and 21.03 kcal mol–1, respectively. In 3-trifluoromethylphenylchloroformate, the atoms C13 is favourable for electrophilic attack. The atoms C2 and C8 are more favourable for nucleophilic attack. The dual descriptors (∆fk, ∆sk and ∆ωk) revealed that the order of nucleophilic attack is C1 > C4 > C2 > C8 > C5. Thus, the present investigation provides complete structure, vibrations and reactivity characteristics of the compound.

1755-1761

Authors: K. Naresh and B.N. Sivasankar*

A new copper complex of pyridine-2,6-dicarboxylate containing hydrazinium cation, formulated as (N2H5)2[Cu(PDC)2]·4H2O (PDC = pyridine-2,6-dicarboxylate) has been synthesized from copper(II) nitrate, hydrazine hydrate and pyridine-2,6-dicarboxylic acid as a single crystal and characterized by elemental analysis and spectroscopic (IR and UV-visible), thermal (TG/DTG), single crystal X-ray diffraction and biological studies. A six-coordinate complex with a distorted octahedral geometry around Cu(II) ion is proposed and confirmed by X-ray single crystal method. The structure reveals that two pyridine-2,6-dicarboxylate species acting as tridentate ligands and hydrazinium cation present as a counter ion along with non-coordinated four water molecules. The structural units of copper(II) is mutually held by the hydrogen bonds and π···π and C–O···π interactions. The copper(II) complex is connected to one another via O–H···O hydrogen bonds, forming water clusters, which plays an important role in the stabilization of the crystal structure. In the water clusters, the water molecules are trapped by the cooperative association of coordination interactions as well as hydrogen bonds. Both cation and anion interactions and crystal from various types of intermolecular contacts and their importance were explored using Hirshfeld surface analysis. This indicates that O···H/H···O interactions are the superior interactions conforming excessive H-bond in the molecular structure. The interaction of copper(II) complex with calf thymus DNA (CT-DNA) was investigated by electronic absorption spectroscopic technique. The electronic evidence strongly shows that the compound interacts with calf thymus through intercalation with a binding constant of Kb = 5.7 × 104 M–1.

1767-1773

Authors: Ravinder Mamidala *, Solomon Raj S. Bhimathati and Aparna Vema

A series of 21 O- and N-Mannich bases of 3,4-dihydropyrimidinones (2a-j and 3a-k) were synthesized by using microwave irradiation technique by multi-component reaction in two steps. All the compounds were evaluated for their free radical scavenging activity by four methods. Structure activity relationship studies revealed that the compounds 2h, 2g, 3h and 3g exhibited profound antioxidant properties compared to standard ascorbic acid. Among O- and N-Mannich bases, N-Mannich bases were found to be more potent in scavenging free radicals. The correlation between structure and activities of these compounds with concern to drug likeliness profile and other physico-chemical parameters are portrayed and verified experimentally

1779-1784

Authors: V. Mohanraj1,2, R. Pavithra1 , M. Thenmozhi3 and R. Umarani1,*

Phenyl trimethylammonium tetrachlorocobaltate, crystals were grown by slow evaporation technique. The crystal was bright, transparent. The three dimensional structure of the phenyl trimethylammonium tetrachlorocobaltate was obtained from single crystal X-ray diffraction studies. The molecule belongs to monoclinic crystal system with C2/c space group. The presence of functional groups and modes of vibrations were identified by FT-IR spectroscopy. 1 H NMR spectroscopy was also used to characterise the compound and the thermal stability of the crystal was established by TGA/DT analysis. This work undergoes phase transition which makes the study interesting

1791-1797

Authors: M.S. Mrudula and M.R. Gopinathan Nair*,

Two shot solution polymerized natural rubber/polyethylene oxide (NR/PEO) block copolymers are used as chelating exchanger for the metal ions Mn(II) and Fe(II). The polymer - metal ion chelates are prepared via solution batch adsorption method and are subjected to various characterisation techniques. Adsorption studies shows 96 and 63 % complexation for Mn(II) and Fe(III) ions, respectively. The 72 helical conformation of PEO and metal-etheric oxygen coordination are confirmed by FT-IR spectroscopy. The XRD results revealed the complete miscibility of metal ions and semi-crystalline nature of samples. The EDX analysis confirmed the presence of metal ions in the polymer chelates. Surface morphology is also studied using SEM and TEM techniques.

1805-1808

Authors: Rajesh Kumar* and Swati Chawla

In this paper, pure and copper doped tin oxide thin films were grown on glass substrates by thermal evaporation technique for gas sensing applications. Optical, structural and gas sensing properties were investigated for their application for gas sensing applications. The thickness of the samples was kept about 300 nm. The films were annealed at 400 ºC for 4 h in the presence of air. The gas sensing studies were carried out for hydrogen sulphide and ethanol gas. The sensitivity was quite high for hydrogen sulphide gas but little sensitivity towards hydrocarbon gases.

1815-1818

Authors: R.N. Yadava* and Jyotsna Raghuvansi

A new flavone glycoside was isolated from ethanolic extract of stem parts of Holmskioldia sanguinea Retz. Its structure was characterized as 3,4′-dihydroxy-5,7-dimethoxyflavone-3-O-β-Dgalactopyranosyl(1→4)-O-β-D-arabinopyranosyl-4′-O-α-L-rhamnopyranoside (1) by colour reactions, chemical degradation and spectroscopic analysis. Antibacterial activity of compound 1 was evaluated against various Gram positive and Gram negative bacteria showing a significant effects.

1825-1829

Authors: A. Vanaja *, Jaison Jeevanandam and M. Suresh

The present work aims at evaluating the outcome of zinc precursors on the crystal structure, shape, surface and optical properties of ZnO nanopowders. Zinc oxide nanopowders are fabricated via simple, cost-effective, low-temperature, the sol-gel method using different zinc precursors such as zinc nitrate and zinc chloride. The structural properties of the obtained ZnO nanopowders are studied using X-ray diffraction spectra and their morphology from SEM micrographs. Further, Fourier transform infrared spectra reveals the existence of functional groups that supports the formation of zinc oxide. Moreover, optical absorption and emission of ZnO nanopowders were evaluate during ultraviolet-visible and photoluminescence spectra. The results of this study revealed that the precursor is significant in altering the crystallite size, shape, optical absorption and emission entities of nanopowders. In addition, the role of zinc precursors to fabricate nanopowders that is suitable for various optoelectronic device applications were also discussed.The present work aims at evaluating the outcome of zinc precursors on the crystal structure, shape, surface and optical properties of ZnO nanopowders. Zinc oxide nanopowders are fabricated via simple, cost-effective, low-temperature, the sol-gel method using different zinc precursors such as zinc nitrate and zinc chloride. The structural properties of the obtained ZnO nanopowders are studied using X-ray diffraction spectra and their morphology from SEM micrographs. Further, Fourier transform infrared spectra reveals the existence of functional groups that supports the formation of zinc oxide. Moreover, optical absorption and emission of ZnO nanopowders were evaluate during ultraviolet-visible and photoluminescence spectra. The results of this study revealed that the precursor is significant in altering the crystallite size, shape, optical absorption and emission entities of nanopowders. In addition, the role of zinc precursors to fabricate nanopowders that is suitable for various optoelectronic device applications were also discussed.The present work aims at evaluating the outcome of zinc precursors on the crystal structure, shape, surface and optical properties of ZnO nanopowders. Zinc oxide nanopowders are fabricated via simple, cost-effective, low-temperature, the sol-gel method using different zinc precursors such as zinc nitrate and zinc chloride. The structural properties of the obtained ZnO nanopowders are studied using X-ray diffraction spectra and their morphology from SEM micrographs. Further, Fourier transform infrared spectra reveals the existence of functional groups that supports the formation of zinc oxide. Moreover, optical absorption and emission of ZnO nanopowders were evaluate during ultraviolet-visible and photoluminescence spectra. The results of this study revealed that the precursor is significant in altering the crystallite size, shape, optical absorption and emission entities of nanopowders. In addition, the role of zinc precursors to fabricate nanopowders that is suitable for various optoelectronic device applications were also discussed.

1835-1841

Authors: Parameswari Kalivel1,*, Jegathambal Palanichamy2 and Mano Magdalene Rubella

Electrocoagulation methods are being used for the alternative treatment process for the remediation of textile waste water. This work primarily deals with the treatment of textile dyeing waste water followed by the utilization of waste material. The purpose of the proposed study is to evaluate the potential of electrocoagulatison process using Ti2O3/Zn electrode prepared by spray pyrolysis using TiCl3 and compared the performance with Zn electrodes. The surface morphology, structural analysis and percentage composition of the elements of the Ti2O3/Zn electrode was studied by SEM, XRD and EDS analysis. The efficiency of electrocoagulation treatment process to treat synthetic waste water containing Coralene Navy RDRLSR, Coralene Red 3G, Rubru RD GLFI dye was studied for the effect of operational parameters. The result indicates that this process was able to achieve colour removal (97.2 %) at pH 8.5, with 34.42 % less energy consumption with Ti2O3/Zn compared with zinc electrodes.

1847-1850

Authors: Pragi *, Jagdeep Singh Dua and Jitender Singh

The present work emphasizes on the synthesis of a series of 4,5-disubstituted isoxazole derivatives of α,β-chalcone ditosylates which were synthesized by the reaction of α,β-chalcone ditosylates with hydroxylamine hydrochloride. Various α,β-chalcone ditosylates were prepared by the reaction of respective chalcones with hydroxyl (tosyloxy)iodobenzene.The synthesized compounds were characterized and subsequently evaluated for anti-inflammatory and antioxidant properties.

1859-1865

Authors: M. Shahinuzzaman *, Zahira Yaakob , Norrakiah Abdullah Sani , Parul Akhtar , Md. Zahidul Islam3 , Mst. Afsana Mimi and Shamsul Akmal Shamsudin

In this study, the extraction parameters for antioxidant activity and total phenolic content of Ficus carica L. latex from White Genoa cultivar were optimized using response surface methodology (RSM). Effect of temperature, extraction time and solvent concentration for maceration extraction were investigated. The antioxidant activity was determined with DPPH (1,1-diphenyl-2-picrylhydrazyl) assay and expressed as percent of inhibition. Total phenolic content (TPC) was determined with Folin-Ciocalteu assay and expressed as µg GAE/mL. The optimum points that maximize the DPPH inhibition are 32 °C temperature, 31.50 min extraction time and 65 % ethanol. The optimum points for TPC are 32 °C temperature, 37.50 min extraction time and 70 % ethanol. The predicted DPPH inhibition and TPC at these predicted points are 67.08 % and 313.811 µg GAE/mL respectively. In this model, the F value (26.03 and 20.96), R-Squared value (0.9591 and 0.9497) and signal to noise ratio (13.431 and 12.799) are reasonable to fit the model.

1871-1876

Authors: Eida S. Al-Farraj , Amani S. Alturiqi , Murefah M. Anazy and Reda A. Ammar *

A novel Co(III) complex derived from hexaadentate Schiff base ligand, H3L was described. The ligand is prepared from the reaction of tris-2-aminoethyl amine and o-vanillin in 1:3 molar ratio. The structure of the ligand and its Co(III) complex was described by micro-analyses, FT-IR, NMR, ESI-MS and UV/visible and thermal stability. DFT study was carried out to get insights into the ligand and its Co(III) complex to compare the values of bond lengths and angles with each other. The electronic spectra, Mulliken atomic charge distribution, HOMO-LUMO energy and the thermodynamic parameters have been calculated.

1881-1884

Authors: Rahma Hashim Abdullah , Iman Fadhil and Amjed Mirza Oda *

Green synthesis route has been used for preparation of silver nanoparticles (AgNPs) by aqueous extract of chard plant (Beta vulgaris). The extract volume was studied as effected parameter in the synthesis of AgNPs and monitored by UV-visible spectrum according to the surface plasmon resonance band that centered at 417 nm. The silver nanoparticles were characterized by FTIR, XRD and SEM. The FTIR anlysis showed the adsorption of biomolecules on the AgNPs surface acting as reducing and capping agent. The XRD results revealed the presence of cubic face silver metal without trace of another silver oxides, as an indication of stability against oxidation. Also XRD in combination with SEM analysis showed that AgNPs are in the nanometric scale with spherical identical shape, where the route was successful. The silver nanoparticles tested against Streptococcus pneumonia and Escherichia coli, where the inhibition zone was 28 and 33 nm, respectively.