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Browsing Journal Article by Author "Amutha Selvi, M"
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- ItemAloe vera Plant Extracted Green Synthesis, Structural and Opto-Magnetic Characterizations of Spinel COxZn1_xAl204 Nano-Catalysts(2015) Amutha Selvi, MSpinel Co^Zn,_,Al204 (0 < x < 1) nano-catalysts were synthesized by a simple Aloe vera plant extracted green synthesis route. Powder XRD patterns and Rietveld analysis confirmed the formation of single phase, cubic spinel gahnite structure without other impurities. The lattice parameter increased from 8.089 to 8.125 A with increasing content. The average crystallite sizes were estimated using Scherrer’s method, and it was found to be in the range of 15.72 nm to 26.53 nm. FT-IR spectra showed vibrational stretching frequencies corresponding to the spinel structure. HRSEM and HR-TEM images showed the features of well particle shaped crystals with nano-sized grains. The elemental compositions of Co, Zn, Al and O were quantitatively obtained from EDX analysis. The band gap energy estimated using Kubelka-Munk method by UV-Visible DRS method, and the values are decreased with increasing the Co^^ content (4.12 eV to 3.67 eV), due to the formation of sub bands in between the energy gap. PL spectra showed emission bands in UV as well as in the visible regions for ZnAIjO^ and Co-doped ZnAl204, due to the defect centers acting as the trap levels. VSM measurements revealed that pure ZnAl204 has diamagnetic, while Co doped ZnAl204 samples (x = 0.2 to 0.8) have superparamagnetism, whereas the sample C0AI2O4 has ferromagnetic in nature. Catalytic oxidation of benzyl alcohol to benzaldehyde was found that the sample Coo 6Zno4Al204 showed 93.25% conversion with 99.56% selectivity, whereas for pure ZnAl204, the conversion was only 86.31% with 92.85% selectivity.
- ItemAntimicrobial Activity of Some of Chlorocobaloximes Containing Axial Substituted Pyridines(2011) Amutha Selvi, MCobaloximes o f the type [Co(dmgH)2(B)Cl] ; where, (ImgET = dimethyl glyoximate, B= 3- chlorpyridine (3-PyCl), 3-bromopyridine (3-PyBr), 4-aminopyridine (4-AP), 4-methylpyridine (4-MP), 4-N,N’-dimethyl aminopyridine (4-DMAP) and 4-cyanopyridine (4-PyCN) were prepared, characterized by the usual .spectroscopic techniques and screened agaimt microorganism for antimicrobial activity with ciprofloxacin as standard. The cobaloximes were found to be active against most o f the microbes. Die cobaloxime containing 4-cyanopyridine as the axial ligand showed potential inhibition; whereas, the complex [Co(dmgH)2(3-PyCl)Cl] showed the least microbial growth.
- ItemAquabromidobis(dimethylglyoximatoR2 N,N')- Cobalt(lll)(2011) Amutha Selvi, M
- ItemAquachloridobis(diphenylglyoximato-R2 N,N')cobalt(III) dihydrate(2011) Amutha Selvi, MActa Crystallographica Section E: Structure Reports Online is the lUCr's highly popular open-access structural journal. It provides a simple and easily accessible publication mechanism for the growing number of inorganic, metal-organic and organic crystal structure determinations. The electronic submission, validation, refereeing and publication facilities of the journal ensure very rapid and high-quality publication, whilst key indicators and validation reports provide measures of structural reliability. The journal publishes over 4000 structures per year. The average publication time is less than one month.
- ItemChloridobis(Dimethylglyoximato-/R 2N,N1) (4-methylpyridine- RN) Cobalt(lll) Bemibydrate(2011) Amutha Selvi, MActa Crystallographica Section E: Structure Reports Online is the lUCr's highly popular open-access structural journal. It provides a simple and easily accessible publication mechanism for the growing number of inorganic, metal-organic and organic crystal structure determinations. The electronic submission, validation, refereeing and publication facilities of the journal ensure very rapid and high-quality publication, whilst key indicators and validation reports provide measures of structural reliability. The journal publishes over 4000 structures per year. The average publication time is less than one month.
- ItemCis-Bis(2,2'-bipyridine-R2 N, N')Dichlorido Cobalt( ll) Tribydrate(2011) Amutha Selvi, MIn the title complex, [CoCl2(CniHnN2)2]-3H20, the Co(II) ion is situated on a twofold rotation axis and exhibits a slightly distorted octahedral geometry and is chelated by four N atoms of the two bidentate 2,2’-bipyridine ligands and two Cl~ ions. The crystal packing is stabilized by hydrogen bonding formed between chloride ions and adjacent water molecules. One of the two independent water molecules in the asymmetric unit is disordered over two sets of sites, each on a twofold rotation axis, in a 0.734 (17);0.269 (17) ratio.
- ItemStructural Aspects Of Diaquotetrakis (imidazole) Cobalt II Choloride(2012) Amutha Selvi, MA pink coloured cobalt(Il) complex viz., [Co(Imi)4(H20)2]Cl2 was prepared by mixing cobalt(II) chloride with imidazole in 1:4 molar ratio in acetone. The complex was characterized by UV, IR, TG-DTA and single crystal XRD studies. The ERR spectrum of the complex proved its paramagnetic nature which was further analyzed by magnetic susceptibility studies. Susceptibility measurements showed the presence of three unpaired electrons accounting for the high spin nature o f the complex.
- ItemStudy of synergistic Influence of l-Cysteine on Polyvinyl Alcohol - Taguchi Method: Continuous Electrochemical Monitoring of Corrosion Inhibition of Mild Steel by Poly(Vinyl Alcohol-Cysteine)(2015) Amutha Selvi, MTo reduce the synthesis time, energy consumption, low cost, Mn”^-doped NiS (Mn,Ni|_,S; jt = 0.0, 0.3 and 0.5) nano-photocatalysts were successfully synthesized by a facile, one-pot, microwave combustion method (MCM) within 10 min. Tn this MCM route, microwave heating has produced such functional nano-photocatalysts within few minutes of time. Powder XRD, FT-TR, EDX and SAED results were confirmed the formation of well crystalline single phase of NiS nano-crystals. The as-prepared samples consist of agglomerated particles with nano-crystals like morphologies confirmed by HR-SEM and HR-TEM analysis. The optical band gap energy (E^) was estimated from UV-Vis DRS and PL study. The value of is increased with
- ItemTRIS-(1, Lo-Phenanthroline) Cobalt (III) Bromide Chloride Hexahydrate: Synthesis, Characterization, Antimicrobial Screening and XRD Studies(2011) Amutha Selvi, MA novel eomplex, tris-( I ,IO-phenanthroline)cobalt(III) bromide chloride, viz., [Co (plien)3 | Br^Cly has been prepared and characterized by IJV-visible, FT-IR and 'll NMR spectral analysis. The single crystal XRD- analysis of the complex reveals that composition of the complex corresponds to [Co (phen)3 )Bri 5CI1 5. OfLO and hence, it may be named, as tris-(l,IO-phenanthroline-k"N,N') cobalt (III) 1.5 bromide 1.5 chloride hexahydrate. The complex was subjected to antimicrobial screening and found to show good activity.