15 research outputs found
4-Bromomethyl-7-methyl-6,8-dinitrocoumarin
The crystal structure of the title compound, C11H7BrN2O6, establishes the substitution positions of the nitro groups from the nitration reaction of 7-methyl-4-bromomethyl coumarin. The mean planes of the nitro groups form dihedral angles of 43.9 (8) and 52.7 (10)° with the essentially planar [maximum deviation 0.031 (6) Å] benzopyran ring system
4-(4-Chlorophenyl)-N-[(E)-4-(dimethylamino)benzylidene]-1,3-thiazol-2-amine
The title compound, C18H16ClN3S, adopts an extended molecular structure. The thiazole ring is inclined by 9.2 (1) and 15.3 (1)° with respect to the chlorophenyl and 4-(dimethylamino)phenyl rings, respectively, while the benzene ring planes make an angle of 19.0 (1)°. A weak intermolecular C—H⋯π contact is observed in the crystal structure
2-(5-Methyl-1-benzofuran-3-yl)acetic acid
The asymmetric unit of the title compound, C11H10O3, contains two crystallographically independent molecules, A and B, with closely matching conformations (r.m.s. overlay fit = 0.105 Å). In each case, the OH group of the acetic acid residue occupies a position approximately antiperiplanar to the C atom of the heterocycle. A short intramolecular C—H...O contact occurs within each molecule. In the crystal, carboxylic acid A+B dimers generate R22(8) loops
Crystal structure of 7,8-benzocoumarin-4-acetic acid
The fused-ring system in the title compound [systematic name: 2-(2-oxo-2H-benzo[h]chromen-4-yl)acetic acid], C15H10O4, is almost planar (r.m.s. deviation = 0.031 Å) and the Car—C—C=O (ar = aromatic) torsion angle for the side chain is −134.4 (3)°. In the crystal, molecules are linked by O—H...O hydrogen bonds, generating [100] C(8) chains, where the acceptor atom is the exocyclic O atom of the fused-ring system. The packing is consolidated by a very weak C—H...O hydrogen bond to the same acceptor atom. Together, these interactions lead to undulating (001) layers in the crystal
2-(5-Methyl-1-benzofuran-3-yl)-N-(2-phenylethyl)acetamide
The title compound, C19H19NO2, is non-planar with the phenyl ring of the phenethylacetamide residue inclined to the benzofuran ring system by 84.8 (3)°. The methyl group lies in the plane of the fused ring system [C—C—C—C torsion angle = −179.6 (3)°]. In the crystal, N—H...O hydrogen bonds link the molecules into chains along the a-axis direction. π–π stacking interactions with a centroid-to-centroid distances of 3.497 (3) Å further stabilize the structure, stacking the molecules along a
2-(2-Amino-1,3-thiazol-4-yl)acetohydrazide
In the title compound, C5H8N4OS, the dihedral angle between the acetohydrazide moiety and the thiazole ring is 80.96 (8)°. In the crystal, molecules are linked by N—H...O and N—H...N hydrogen bonds generating (010) sheets
Effect of sintering on optical, structural and photoluminescence properties of ZnO thin films prepared by sol-gel process
Zinc oxide (ZnO) thin films have been deposited on glass substrates via sol-gel technique using zinc acetate dihydrate as precursor by spin coating of the sol at 2000 rpm. Effects of annealing temperature on optical, structural and photo luminescence properties of the deposited ZnO films have been investigated. The phase transition from amorphous to polycrystalline hexagonal wurtzite structure was observed at an annealing temperature of 400 degrees C. An average transmittance of 87% in the visible region has been obtained at room temperature. The optical transmittance has slightly increased with increase of annealing temperature. The band gap energy was estimated by Tauc's method and found to be 3.22 eV at room temperature. The optical band gap energy has decreased with increasing annealing temperature. The photoluminescence (PL) intensity increased with annealing temperature up to 200 degrees C and decreased at 300 degrees C. (c) 2010 Elsevier B.V. All rights reserved