Effect of cobalt doping on structural, thermo and photoluminescent properties of ZnO nanopowders

Nanocrystalline cobalt doped zinc oxide nanoparticles are synthesized by solution combustion method using sucrose as a fuel. The synthesized samples are characterized by XRD, SEM, FTIR, Micro-Raman, UV�Visible techniques. XRD studies confirm that both undoped and Co doped samples exhibit hexagonal wurtzite structure with crystallite size ~30 nm for undoped ZnO and 25�18 nm for Co doped ZnO samples. Both undoped and Co doped samples exhibit Raman peaks at 432, 502, 578, 681, 766, 865, 967 and 1175 cm�1. Intensity of E2 (high) mode of ZnO appeared at 432 cm�1 and decreases drastically with increase in cobalt concentration. Photoluminescence (PL) of all the samples shows violet emission peaks at 361, 398 nm, blue emission peaks at 468,492 nm and weak green emission peaks at 517 and 567 nm. PL intensity is found to decrease with the increase in Co2+ doping. Thermoluminescence (TL) glow curves of Co doped ZnO nano crystalline phosphors are γ-irradiated in the dose range 0.1�5.0 kGy. Prominent glow peaks at 412 and 575 K are observed for all the exposed doses without changing its glow peak structure. TL intensity increases linearly with γ-dose up to 4 kGy. The Kinetic parameters of TL glow are calculated by deconvolution technique. Activation energy and frequency factor are found to be 1.35 eV and 2.10�1011 s�1 respectively. © 201

Luminescence properties of La2O3:Eu3+ nanophosphor prepared by sol-​gel method

Undoped and Eu3+ doped La2O3 nanophosphor are synthesized by low temp. sol-​gel technique. The synthesized samples are characterized by X-​ray diffraction (XRD) and av. crystallite size is found to be ∼18 nm and ∼23 nm for undoped and Eu3+ doped La2O3 resp. Gamma ray irradiated undoped La2O3 shows high intense thermoluminescence (TL) glow peak at 640 K and weak TL glow peak at 443 K and the high intense peak intensity is sub linear increase with γ-​dose. Whereas Eu3+ doped La2O3 nanophosphor show a prominent TL glow peak at 640 K and its TL intensity linearly increases up to 1 kGy. The kinetic parameters are estd. using glow curve deconvoluted (GCD) technique. TL emission of γ-​ray irradiated Eu3+ doped La2O3 show peaks at 508, 586, 619 and 706 nm are attributed to Eu3+ transition peaks

Molecular Docking Studies of 2-Mercapto-5-(3-Methoxyphenyl) 1, 3, 4 Oxadiazole Thiones with Focal Adhesion Kinase

The main objective of the present work is to perform molecular docking studies of the ligand 2- Mercapto-5-(3-Methoxy phenyl) 1,3,4 oxadiazole with protein focal adhesion kinase. A good correlation was observed in binding affinity of this complex. Using different inhibitors for this enzyme, it can be used as an anticancer therapy target

Thermoluminescence Studies of γ-Irradiated ZnO:Mg2+ Nanoparticles

Pure and Mg2+ doped ZnO nanoparticles are synthesized by solution combustion method. X-ray diffraction studies of the samples confirm hexagonal phase. Crystallite size is calculated using Scherer formula and found to be ∼30 nm for undoped ZnO and 34–38 nm for Mg2+ doped ZnO. A broad PL emission in the range 400–600 nm with peaks at 400, 450, 468, 483, 492, 517, 553 nm are observed in both pure and Mg2+ doped nanoparticles. Near band edge emission of ZnO is observed at 400 nm. The broad band emissions are due to surface defects. PL emission intensity is found to increase with Mg2+ concentration up to 1.5 mol% and then decreases due to concentration quenching. Samples are irradiated with γ-rays in a dose range 0.05–8 kGy. Gamma irradiation doesn’t affect PL properties. Undoped samples exhibit unstructured low intense TL glow with peak at 720 K. Whereas Mg2+ doped samples exhibit well structured TL glow curves with peak at ∼618 K. TL glow peak intensity of Mg2+ doped samples increases with Mg2+ concentration up to 2 mol%, thereafter decreases. TL curves of Mg2+ (2 mol%) doped ZnO exhibit two glows, a high intense peak at 618 K and a weak one with peak at ∼485 K. TL intensity of Mg2+ (2 mol%) doped ZnO samples increases with gamma dose up to 1 kGy and then decreases. Kinetic parameters of TL glows are calculated by deconvolution technique. Activation energy and frequency factor are found to be 1.5 eV and 3.38 × 1011 s−1 respectively

4-​Amino-​N-​(2-​pyrimidinyl)​benzenesulfonamide

The structure of the title compd., C10H10N4O2S, was detd. The two six-​membered rings are planar and folded towards each other making an acute angle of 74.9(2)​°. The mols. are linked by intermol. N-​H...O and N-​H...N bonds

Structure of 4,​6-​diacetylresorcinol

The title compd. is monoclinic, space group P21/c, with a 7.089(1)​, b 11.361(1)​, c 11.656(1) Å, and β 100.45(3)​°; Z = 4, dm = 1.410(5)​, dc = 1.397; T = 300 K; final R = 0.057 for 1701 reflections. At. coordinates are given. The mol. is almost planar, with O(9) and O(12) of the acetyl groups deviating by 0.074(1) and 0.071(2) Å from the mean plane of the benzene ring. The bond lengths and bond angles of the benzene ring are normal. There are intramol. H bonds between O(9) and H(14) and between O(12) and H(13)​; there are no intermol. H bonds. The mols. are packed in layers parallel to the ac plane and are held together essentially by van der Waals interactions

N-(3-chlorophenyl)-2-(1E)-(4-methylphenyl)-methyleneamino-4,5,6, 7-tetrahydro-1-benzo-thiophene-3-carboxamide

The crystal structure of the title compound, C23H 21ClN2OS, is stabilized by intramolecular N-H⋯N, C-H⋯S and C-H⋯O hydrogen bonds and a weak intermolecular C-H⋯O interaction. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved

6-Methyl-N-(4-methoxy-phen-yl)-2-(E)-(4-methyl-phen-yl)methyl-eneamino-4, 5,6,7-tetra-hydro-thieno2,3-cpyridine-3-carboxamide

The molecular structure of the title compound, C24H25N3O2S, is stabilized by intra-molecular N - Hâ¯N, C - Hâ¯O and C - Hâ¯S hydrogen bonds. There are no significant inter-molecular inter-actions. © 2008

Crystal and molecular docking studies of 3-​[Bis-​(2-​hydroxy-​4,​4-​dimethyl-​6-​oxo-​cyclohex-​1-​enyl)​-​methyl]​benzonitrile with focal adhesion kinase inhibitors

In the present study crystal structure of 3-​[Bis-​(2-​hydroxy-​4,​4-​dimethyl-​6-​oxo-​cyclohex-​1-​enyl)​-​methyl]​benzonitrile was detd. using single crystal X-​ray diffraction. Further the structural features was extrapolated to mol. docking studies with focal adhesion kinase (FAK) domain using Autodock to study its anticancerous property. The compd. exhibited considerable bacterial inhibition of lower to moderate concns. We conclude that these derivs. can be used in medicine and have enormous potential as pharmaceutical agents due to their biol. activities. The above titled receptor gain functional and structural insights into their mechanism of inhibition and explore its potential as an anticancer agent

Combustion synthesis, characterization and Raman studies of ZnO nanopowders

Spherical shaped ZnO nanopowders (14-50 nm) were synthesized by a low temperature solution combustion method in a short time <5 min. Rietveld analysis show that ZnO has hexagonal wurtzite structure with lattice constants a = 3.2511(1) , c = 5.2076(2) , unit cell volume (V) = 47.66(5) () 3 and belongs to space group P63mc. SEM micrographs reveal that the particles are spherical in shape and the powders contained several voids and pores. TEM results also confirm spherical shape, with average particle size of 14-50 nm. The values are consistent with the grain sizes measured from Scherrer's method and Williamson-Hall (W-H) plots. A broad UV-vis absorption spectrum was observed at �375 nm which is a characteristic band for the wurtzite hexagonal pure ZnO. The optical energy band gap of 3.24 eV was observed for nanopowder which is slightly lower than that of the bulk ZnO (3.37 eV). The observed Raman peaks at 438 and 588 cm -1 were attributed to the E 2 (high) and E 1 (LO) modes respectively. The broad band at 564 cm -1 is due to disorder-activated Raman scattering for the A 1 mode. These bands are associated with the first-order Raman active modes of the ZnO phase. The weak bands observed in the range 750-1000 cm -1 are due to small defects. © 2011 Elsevier B.V. All Rights Reserved