806-807The complex Mo2O4(dto)2 (dto = dithiooxamide) has a magnetic moment of 0.51B.M. The electronic spectral data (450 nm) indicate the presence of Mo2O42+ core. The negative shifts (50 cm-1) and spitting in v(CN) and v(CS) bands... more
806-807The complex Mo2O4(dto)2 (dto = dithiooxamide) has a magnetic moment of 0.51B.M. The electronic spectral data (450 nm) indicate the presence of Mo2O42+ core. The negative shifts (50 cm-1) and spitting in v(CN) and v(CS) bands indicate the uninegative bidentate nature of dithiooxamide. The bands at 970, 740 and 480 cm-1 indicate the presence of terminal (Mo=O1) and bridging (MoOb) Mo groups. The complex exhibits and irreversible cathodic wave (-1.30 vs SCE) characteristic of a Mo2O42+ core. A di-μ-oxo bridged structure with dithiooxamide completing five coordination around each Mo is proposed
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The perovskite oxides, Sm 1− x Sr x CrO 3 (0≤ x ≤0.1) were synthesized by a microwave assisted combustion route from the constituent metal nitrates and urea. The single-phase oxides were characterized by X-ray diffraction (XRD) and the... more
The perovskite oxides, Sm 1− x Sr x CrO 3 (0≤ x ≤0.1) were synthesized by a microwave assisted combustion route from the constituent metal nitrates and urea. The single-phase oxides were characterized by X-ray diffraction (XRD) and the lattice parameters were evaluated. The perovskite oxides were subjected to DC conductance measurements over the temperature range 100–300 °C in air atmosphere from which activation energies were determined. The current was found to increase linearly with the applied field and exponentially against temperature indicating the ohmic nature of the electrode contacts. The activation energy values for DC conductance were found to be in the range of 0.38–0.56 eV. DC resistance measurements as a function of relative humidity in the range of 5–98% RH were carried out on sintered discs at 25 °C under static conditions from which the sensitivity factor, S f ( R 5% / R 98% ) for SmCrO 3 , Sm 0.95 Sr 0.05 CrO 3 and Sm 0.90 Sr 0.10 CrO 3 were calculated to be 2198,...
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The kinetics and mechanism of the two-step reactions occurring in the precursor powders for the formation of the R2Ba4Cu6O13 (R=Y, La, Nd, Sm, Eu or Er) by citrate-fire method were studied by employing dynamic TG at linear heating rates... more
The kinetics and mechanism of the two-step reactions occurring in the precursor powders for the formation of the R2Ba4Cu6O13 (R=Y, La, Nd, Sm, Eu or Er) by citrate-fire method were studied by employing dynamic TG at linear heating rates of 5, 10 and 20°C/min in static air. The two-step reaction sequence occurring in the precursors comprising essentially R(OH)3 (or RO(OH)/R2O3),
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Thick and hard chromium nitride (CrN) films have been developed by plasma assisted metal organic chemical vapor deposition (PAMOCVD) technique. The coating has been characterized using X-ray diffraction, scanning electron microscopy and... more
Thick and hard chromium nitride (CrN) films have been developed by plasma assisted metal organic chemical vapor deposition (PAMOCVD) technique. The coating has been characterized using X-ray diffraction, scanning electron microscopy and analytical and conventional transmission electron microscopy. The coating exhibits two phenomena on different length scales: (i) formation of nanocrystals, and (ii) the formation of the globular structure on a micron scale. These globules are thought to be clusters of nanocrystalline CrN. Cross-sectional transmission electron microscopy of the film has revealed an extremely complex microstructure. However, the film has been found to have uniform Cr incorporation. The coating cross-section has shown bands of varying contrast. It has been shown that adhesion of the coating can be improved by corrugating the substrate surface.
Research Interests: Materials Engineering, Condensed Matter Physics, Materials Science, Microstructure, Scanning Electron Microscopy, and 15 moreTransmission Electron Microscopy, Clusters, Coating, Plasma, Nitrides, Chromium, Surface Morphology, Surface and Coatings Technology, Cross Section, Length scale, Microstructures, Nitride, J, Metal Organic Chemical Vapor Deposition, and Hard coatings
... 14871490, 1993 Printed in Great Britain 02775387 93 6.00 + .00 1993 Pergamon Press Ltd IRONMOLYBDENUMSULPHUR AND IRONTUNGSTEN SULPHUR COMPLEXES OF DIIMINES VASANTHI LAKSHMANAN, KS NAGARAJA* and MR UDUPAt Department of Chemistry ...
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Metallo-organic complexes of titanium such as [Ti (bzac) 2 (OiPr) 2](1) and [Ti (bzac) 2en (OiPr) 2](2) were synthesised using 1-phenyl-1, 3-butanedione (bzac) and the Schiff's base ligand N, N′-ethylene-bis (1-phenyl-1,... more
Metallo-organic complexes of titanium such as [Ti (bzac) 2 (OiPr) 2](1) and [Ti (bzac) 2en (OiPr) 2](2) were synthesised using 1-phenyl-1, 3-butanedione (bzac) and the Schiff's base ligand N, N′-ethylene-bis (1-phenyl-1, 3-butanediimine)[(bzac) 2en]. A novel ligand 1-...
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... S. Arockiasamy a , Corresponding Author Contact Information , 1 , E-mail The Corresponding Author , C. Mallika b , OM Sreetharan d , VS Raghunathan c and KS Nagaraja a , Corresponding Author Contact Information , E-mail The... more
... S. Arockiasamy a , Corresponding Author Contact Information , 1 , E-mail The Corresponding Author , C. Mallika b , OM Sreetharan d , VS Raghunathan c and KS Nagaraja a , Corresponding Author Contact Information , E-mail The Corresponding Author. ...
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The metal Schiff base complexes of bis(N-isopropylsalicylaldimine)coblt(II), bis(N-isopropylsalicylaldimine)nickel(II) and bis(N-isopropylsalicylaldimine)zinc(II) were prepared by simple combination of the metal salts with the ligands in... more
The metal Schiff base complexes of bis(N-isopropylsalicylaldimine)coblt(II), bis(N-isopropylsalicylaldimine)nickel(II) and bis(N-isopropylsalicylaldimine)zinc(II) were prepared by simple combination of the metal salts with the ligands in the right proportions via a condensation reaction. These complexes were characterized by various spectroscopic techniques.Formations of the nitrogen coordination with metal and the wavelengths of maximum adsorption complexes were confirmed by FT- IR and UVvisible spectroscopy respectively. Determination of the melting points and the volatility of the complexes were studied by TGA/DTA analysis. The complexes were found to be volatile based on the TG/DTA study. The volatile complexes would also be studied by (EI-MS) to determine the molecular formulae and the corresponding molecular weight. The binaryphase diagrams of Co(salisopropylamine)2 - Ni(salisopropylamine)2; Ni(salisopropylamine)2 - Zn(salisopropylamine)2 and Co(salisopropylamine)2 Zn(salisopr...
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MoO3 dissolved in HCl and DMF reacts with thiosemicarbazide to yield the title complex.
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ABSTRACT A group of metallo-organic complexes of copper, namely bis(N-R-salicylaldiminato)Cu(II) (R: methyl to n-pentyl, hereafter referred to as 1–5) were prepared and their volatile nature was confirmed by TG/DTA. The molecular masses... more
ABSTRACT A group of metallo-organic complexes of copper, namely bis(N-R-salicylaldiminato)Cu(II) (R: methyl to n-pentyl, hereafter referred to as 1–5) were prepared and their volatile nature was confirmed by TG/DTA. The molecular masses (M) of 1–5 were confirmed by mass spectrometry. The vapour pressure (pe) for precursors 1–5 determined by a transpiration technique using the Clausius–Clapeyron relation yielded the values of 91 ± 2, 84 ± 4, 100 ± 2, 92 ± 2, and 72 ± 2 kJ mol−1 for ΔHovap, respectively, for 1–5. The thin films deposited by plasma-assisted MOCVD technique contain predominantly metallic copper in <111> orientation. The SEM images of the thin films exhibit continuous nanoball-like structure.
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Zirconia ceramics are remarkable materials, due to excellent mechanical and electrical properties. The high operating temperature of 1273 K limits the expansion of applications due to thermal stresses and rapid degradation of materials.... more
Zirconia ceramics are remarkable materials, due to excellent mechanical and electrical properties. The high operating temperature of 1273 K limits the expansion of applications due to thermal stresses and rapid degradation of materials. Extensive researches have been conducted to reduce electrolyte resistance at reduced temperatures and the replacing YSZ with other suitable material or by reducing the thickness of the electrolyte to lower ohmic losses. The present study was made to solve these problems by a novel process of plasma assisted MO and LICVD technique on different surfaces. The completely volatile and non-toxic precursors of scandium have been developed and temperature dependence equilibrium vapour pressure using TG based transpiration technique has been measured. The films of ScSZ and Al2O3 doped ScSZ depositions by modified CVD technique along with surface characterisation have been carried out.
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... The results revealed that the sensitivity factor (S f ) increased with temperature up to the optimum temperature at which maximum sensitivity is obtained and thereafter decreased. ... Table 1. Surface area parameters of CoSA1, SA and... more
... The results revealed that the sensitivity factor (S f ) increased with temperature up to the optimum temperature at which maximum sensitivity is obtained and thereafter decreased. ... Table 1. Surface area parameters of CoSA1, SA and CoSA5 composites S. no. Parameters, CoSA1, ...
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ABSTRACT Nanocrystalline cubic Y2O3 film deposition by PA-LICVD was studied at 773 K in a N2/O2 plasma environment with methanol and triglyme solution of aquatris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and its polyether... more
ABSTRACT Nanocrystalline cubic Y2O3 film deposition by PA-LICVD was studied at 773 K in a N2/O2 plasma environment with methanol and triglyme solution of aquatris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and its polyether adduct complexes as precursors. The X-ray powder patterns are analyzed and found to be triclinic and monoclinic for Y(tmhd)3·H2O(1) and Y2(tmhd)6·triglyme (2). Y2O3 film with (111) plane as the dominant orientation was obtained on graphite under a deposition pressure of 0.8–1.2 mbar.
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ABSTRACT The volatile scandium-β-diketonates are synthesised using acetylacetone (acac) and tetramethylheptanedione (tmhd) as coordinative ligands for CVD application. The X-ray powder patterns are indexed and analysed and found to be... more
ABSTRACT The volatile scandium-β-diketonates are synthesised using acetylacetone (acac) and tetramethylheptanedione (tmhd) as coordinative ligands for CVD application. The X-ray powder patterns are indexed and analysed and found to be orthorhombic and monoclinic phases for Sc(acac) 3 (1) and Sc(tmhd) 3 (2) respectively. The sublimation and evaporation kinetics have been analyzed using three calculating techniques. The non-isothermal based activation energy values are found to be 38 ± 2 and 73 ± 2 kJ mol −1 by Flynn–Wall technique for (1) and (2) respectively. The measured E a values are close to the value obtained using Kissinger method.
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ABSTRACT Export Date: 21 December 2012, Source: Scopus
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Complexes of the types M(Me) x (H 20). [MeH = 2morpholinoethanol; M =Co(ll) or Ni(II), n =3; M =Cu(ll), n =2; M =Zn(ll) or Cd(II), n=l] and [Hg(MeH)4]X2 (X=CI or Br) have been prepared and characterized. The IR spectral studies indicate... more
Complexes of the types M(Me) x (H 20). [MeH = 2morpholinoethanol; M =Co(ll) or Ni(II), n =3; M =Cu(ll), n =2; M =Zn(ll) or Cd(II), n=l] and [Hg(MeH)4]X2 (X=CI or Br) have been prepared and characterized. The IR spectral studies indicate that MeH is bonded through nitrogen atom in mercury complexes and as a univalent bidentate ligand in other complexes. The electronic spectral data and magnetic moments of cobalt(II), nicke~1I)and copper(Il) complexes suggests sixcoordination around these metal atoms. The subnormal magnetic moments (1.0 B.M.) of copper(Il) complexes sugge9t a dimeric structure. The conductance measurements support the ionic nature of the mercury(ll) complexes. The complexes decompose on heating to stable metal oxides after the step-wise removal of water and the ligands.
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Heterobinuclear complexes (MnMo02 (L).(H20)] and (HgMo02 (L), (H20)] (Ldiethyldithiocarbamate, 4-morpholinyldithiocarbamate, l-piperidinyldithiocarbamate) have been prepared and characterized. The magnetic moment, EPR and PES spectral... more
Heterobinuclear complexes (MnMo02 (L).(H20)] and (HgMo02 (L), (H20)] (Ldiethyldithiocarbamate, 4-morpholinyldithiocarbamate, l-piperidinyldithiocarbamate) have been prepared and characterized. The magnetic moment, EPR and PES spectral data suggest the presence of manganese(III) or mercury(II) with molybdenum(V) in the complexes. The 1Hand l3C NMR chemical shifts of the complexes indicate the presence of two types of dithiocarbamates coordinated to molybdenum and a heterometal atom. The redox behaviour of the complexes are discussed from CVM data. The proposed structure consists of an octahedral manganese(III) or mercury(ll) and distorted octahedral molybdenum(V) bridged by ail oxo group.
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Mesoporous activated carbon was prepared from Bael tree bark (ACBTB) by impregnation with phosphoric acid at 450 ◦ C. Materials were characterized for their surface chemistry by Boehm titrations, point of zero charge measurements, Fourier... more
Mesoporous activated carbon was prepared from Bael tree bark (ACBTB) by impregnation with phosphoric acid at 450 ◦ C. Materials were characterized for their surface chemistry by Boehm titrations, point of zero charge measurements, Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), as well as for their porous and morphological structure by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77 K for the surface area. The effects of contact time, adsorbent dose, temperature, concentration and pH have been studied under batch system for Erythrosine-B (EB) dye. Adsorption isotherms were determined using Langmuir, Freundlich and Dubinin-Radushkevich models. The experimental data fitted best to the Langmuir model. The pseudo first order, pseudo second order and intra particle diffusion models were used to examine the kinetic data. The results obtained showed that kinetic data were well described by the second order model. Thermodynamic studies show...
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Nicotine(l) is the alkaloid present in the tobacco plant and it is toxic I.E venthough some of the addition compounds of nicotine with metal salts have been reported2-4, no systematic characterization of the complexes has been carried... more
Nicotine(l) is the alkaloid present in the tobacco plant and it is toxic I.E venthough some of the addition compounds of nicotine with metal salts have been reported2-4, no systematic characterization of the complexes has been carried out. We have recently reporteds nicotine complexes of cobalt(II), nickel(ll) and copper(U). We report in the present note, preparation and characterization of the complexes formed by nicotine with zinc(II), cadrnium(I1) and mercury(II) .. Nicotine was a BDH (England) sample and was used without further purification.
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The interaction of tetraoxomolybdate or tetraoxo ngstate with iron(lI) diimines gives compounds of the ty (LFeOzMOz)(L = 2,2'-bipy, I, IO-phen; M = Mo or W . The magnetic studies suggest the presence of high spin iro II) in the... more
The interaction of tetraoxomolybdate or tetraoxo ngstate with iron(lI) diimines gives compounds of the ty (LFeOzMOz)(L = 2,2'-bipy, I, IO-phen; M = Mo or W . The magnetic studies suggest the presence of high spin iro II) in the complexes. The IR spectral studies indicate t e bonding of diimine to iron(II) and the bidentate nature 0 MO/ ~ group ligated to iron(II). Thermal decomp ition behaviour of the complexes is reported. Iron(II)' d molybdenum(VI) or tungsten(VI) are bridged by dioxo groups completing tetrahedral geometry.
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701 green complex was removed by filtration, washed initially with distilled water and finally with MeOH and drie"d,yield 70%. Its X-ray diffraction pattern showed dhkl values: 1O.65s, 8.19s, 6.42m, 5.59w, 5.15s, 4.80m, 4.00w, 3.85w,... more
701 green complex was removed by filtration, washed initially with distilled water and finally with MeOH and drie"d,yield 70%. Its X-ray diffraction pattern showed dhkl values: 1O.65s, 8.19s, 6.42m, 5.59w, 5.15s, 4.80m, 4.00w, 3.85w, 3.65s, 3.43s, 3.35m, 3.19m, 2.90m, 2.90s, 2.85w, 2.39s, 2.37w. Ni4MoOz(4-Morphdtc)g(HzO)4 (2) was also prepared following the above procedure. Its dhk1 (A) values were: 1l.63m, 1O.28s, 7.69m, 6.46s, 5.28w, 4.17w, 3.95s, 3.60s, 3.40m.