Dichloridobis(1-ethyl-2,6-dimethyl­pyridinium-4-olate-κO)zinc(II)

In the title compound, [ZnCl2(C9H13NO)2], the ZnII ion is coordinated by two Cl− anions and two O atoms of two zwitterionic organic ligands in a distorted tetra­hedral arrangement. In the crystal, mol­ecules are linked into sheets parallel to the bc plane by C—H⋯Cl and C—H⋯O hydrogen bonds and weak π–π inter­actions [centroid–centroid distance = 3.669 (1) Å]

Dibromidobis(1-ethyl-2,6-dimethyl­pyridinium-4-olate-κO)zinc(II)

In the bioactive title compound, [ZnBr2(C9H13NO)2], the ZnII atom is coordinated in a distorted tetra­hedral arrangement by two Br− anions and the O atoms of two zwitterionic organic ligands. The pyridinium rings are almost planar [maximum deviations = 0.004 (4) and 0.003 (4) Å]. The ethyl groups are approximately perpendicular to the corresponding pyridinium ring planes [N—C—C—C = 88.8 (4)° in each ligand]. The packing of the mol­ecules is controlled by π–π inter­actions, with centroid–centroid distances of 3.625 (3) and 3.711 (2) Å, forming chains approximately parallel to (102). The crystal studied was non-merohedrally twinned (twin relationship between the domains 1 0 0, 0 1 0, −0.4672 −0.1864 −1 and batch scale factor of 7.39%)

Combustion and deposit formation behavior on the fireside surfaces of a pulverized fuel boiler fired with a blend of coal and petroleum coke

The thermochemistry of the combustion of a blend of coal and 5% petroleum coke was analyzed. Thermodynamic modeling and microscopic techniques were used to study the behavior of the inorganic constituents upon combustion of the blend of coal and petroleum coke. The chemical composition and phase constitution of the combustion products, as well as the deposits at several temperatures corresponding to those at the various parts of the boiler, were deduced by free-energy minimization. These results were compared with actual results obtained from a commercial pulverized fuel boiler fired with coal and petroleum coke blend. The deposits on the fireside surfaces of the boiler tubes in the various parts (water walls, platen superheater, final superheater, economizer, and electrostatic precipitator) of the commercial pulverized fuel boiler fired with coal and 5% petroleum coke were characterized by particle size analysis, chemical analysis, x-ray diffraction, optical microscopy, and scanning electron microscopy. The combustion gas composition was measured using a portable on-line gas analyzer for N 2 , O 2 , CO 2 , H 2 O, CO, NO, and SO 2 . The thermodynamically predicted compositions and phase constitutions for the gas phase as well as the condensed phases are in good agreement with the experimental results

Crystal growth of phase matchable new organic nonlinear optical material for UV laser generation

L-Histidinium tetrafluorosuccinate (L-HFS), an organic nonlinear optical material has been synthesized and characterized by the elemental analysis, FT-IR, FT-NMR and X-ray diffraction studies. Solubility Of L-HFS was found to be higher in water than ethanol, Single crystals with dimensions 10mm x 6 mm x 3 rum were grown in an aqueous solution by the slow evaporation technique at 30 degrees C. The thermal stability of L-HFS has been analyzed by thermogravimetric and differential thermal analyses (TGA and DTA). The UV-vis spectral study reveals that the material has a wide optical transparency in the entire visible region with the lower cutoff wavelength at 235 nm. The phase matching condition was obtained by Kurtz powder second harmonic generation (SHG) efficiency test. The laser darn age threshold of the grown crystal was measured using a Q-Switched Nd:YAG laser (1064 nm). (c) 2007 Elsevier B.V. All rights reserved

Laser induced surface damage, thermal transport and microhardness studies on certain organic and semiorganic nonlinear optical crystals

N-alkyl-2,6-dimethyl-4(1H)-pyridinones, salts of 4-dimethylaminopyridine and 2-amino-5-nitropyridine are considered to be potential candidates for nonlinear optical (NLO) applications, in particular for the generation of blue-green laser radiation. Single crystals were grown following the slow evaporation technique at constant temperature. Single-shot laserinduced surface damage thresholds in the range 3–10 GW/cm2 were measured using a 18 ns Q-switched Nd:YAG laser. The surface morphologies of the damaged crystals were examined under an optical microscope and the nature of damage identified. The Vicker’s microhardness was determined at a load of 98.07 mN. The thermal transport properties, thermal diffusivity (α), thermal effusivity (e), thermal conductivity (K) and heat capacity (Cp), of the grown crystals were measured by an improved photopyroelectric technique at room temperature. All the results are presented and discussed.Cochin University of Science and Technology,Raja Ramanna Centre for Advanced Technology & Bharathidasan University

4-Hydroxy-1,2,6-trimethylpyridinium chloride monohydrate

In the crystal of the title hydrated molecular salt, C8H12NO+·Cl−·H2O, the water molecule makes two O—H...Cl hydrogen bonds, generating [010] zigzag chains of alternating water molecules and chloride ions. The cation is bonded to the chain by an O—H...O hydrogen bond and two weak C—H...Cl interactions. Weak aromatic π–π stacking [centroid–centroid separation = 3.5175 (15) Å] occurs between the chains