536 research outputs found
4-(3-Methoxyphenyl)-1-(2-oxoindolin-3-ylidene)thiosemicarbazide
In the title compound, C16H14N4O2S, intramolecular N—H⋯N hydrogen bonding forms an S(5) ring, whereas N—H⋯O and C—H⋯S interactions complete S(6) ring motifs. In the crystal, molecules form inversion dimers due to N—H⋯O interactions. The dimers are interlinked through N—H⋯S hydrogen bonds and π–π interactions occur with a centroid–centroid distance of 3.8422 (11) Å between the methoxy-containing benzene ring and the five-membered heterocyclic ring
1-(2-Oxoindolin-3-ylidene)-4-[2-(trifluoromethoxy)phenyl]thiosemicarbazide
The crystal structure of the title compound, C16H11F3N4O2S, is stabilized in the form of polymeric chains by N—H⋯O interactions. In the molecular structure, two S(5) ring motifs are formed by intramolecular N—H⋯N and N—H⋯O hydrogen bonding and two S(6) rings are present due to N—H⋯O and C—H⋯S interactions. π–π interactions are present with distances of 3.2735 (17), 3.563 (2) and 3.664 (4)/3.688 (3) Å between the centroids of the heterocyclic rings, between the centroids of the heterocyclic ring and trifluoromethoxy-substituted phenyl ring, and between the centroids of the trifluoromethoxy-substituted phenyl rings, respectively. The trifluoromethoxyphenyl group is disordered over two sites with an occupancy ratio of 0.642 (10):0.358 (10)
1-[2-Oxo-5-(trifluoromethoxy)indolin-3-ylidene]-4-[4-(trifluoromethyl)phenyl]thiosemicarbazide
In the title compound, C17H10F6N4O2S, an intramolecular N—H⋯N hydrogen bonds forms an S(5) ring whereas N—H⋯O and C—H⋯S interactions complete S(6) ring motifs. The dihedral angle between the fused ring system and the phenyl ring is 6.68 (8)°. In the crystal, the molecules are dimerized due to N—H⋯O interactions. π–π interactions are present between the benzene rings [centroid–centroid distance = 3.6913 (15) Å] and between the five membered ring and the trifluoromethyl)phenyl ring [centroids–centroid distance = 3.7827 (16) Å]. One of the trifluoromethoxy F atoms is disordered over two sites with occupancy ratio of 0.76 (3):0.24 (3). The F atoms of the p-trifluoromethyl substituent are disordered over three sets of sites with an occupancy ratio of 0.70 (2):0.152 (11):0.147 (13)
PM2.5 chemical source profiles of emissions resulting from industrial and domestic burning activities in India
A study has been performed to develop PM2.5 (particles with aerodynamic diameters ≤ 2.5) chemically speciated source profiles of different industrial and domestic burning practices in India. A total of fifty-five PM2.5 samples have been collected in emissions resulting from (1) industrial furnaces, (2) household fuels, (3) municipal solid waste burning, and (4) welding workshop burning practices, and categorized for eleven subtypes of sources. The collected samples were subjected to chemical analysis for twenty-one elemental (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, S, Sb, Se, V, Zn), nine ionic (Na+, K+, Mg2+, Ca2+, NH4+, Cl–, F–, NO3–, SO42–), OC, and EC source indicator species using atomic absorption spectrometry, ion chromatography and carbon analysis (thermal/optical transmittance method), respectively. The carbonaceous fraction was most abundant in household fuel burning emissions (47.6 ± 7.45% to 65.92 ± 13.13%). The ionic/elemental ratios of major inorganic constituents (Ca2+/Ca, Mg2+/Mg and Na+/Na) have been identified to describe the PM2.5 emissions from combustion or re-suspension dusts during industrial activities. Brick Kiln processes (BKP) have been identified as the major emitter of the highest number of toxic species (Cd, Co, Mo, Sb and V), followed by steel re-rolling mills (Hg and Pb) and steel processing industries (As, Ni). The source marker calculations also confirmed that K+, Mn, and As are good markers for biomass burning, metallurgical industrial emission, and coal burning, respectively, similar to the findings in previous studies
4-(3-Nitrophenyl)-1-(2-oxoindolin-3-ylidene)thiosemicarbazide
In the title compound, C15H11N5O3S, intramolecular N—H⋯N hydrogen bonding forms an S(5) ring motif, whereas N—H⋯O and C—H⋯S interactions type complete S(6) ring motifs. The 2-oxoindoline and 3-methoxyphenyl rings are almost planar, with r.m.s. deviations of 0.0178 and 0.0149 Å, respectively, and form a dihedral angle of 33.59 (3)°. In the crystal, molecules are interlinked through the nitro groups in an end-to-end fashion via N—H⋯O and C—H⋯O interactions
4-(2-Fluorophenyl)-1-(2-oxoindolin-3-ylidene)thiosemicarbazide
The title compound, C15H11FN4OS, is almost planar, the dihedral angle between the aromatic ring systems being 5.00 (13)°. The conformation is stabilized by intramolecular N—H⋯N and N—H⋯O hydrogen bonds, which generate S(5) and S(6) rings, respectively. N—H⋯F and C—H⋯S interactions also occur. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur, generating R
2
2(8) loops
4-(2-Ethylphenyl)-1-(2-oxoindolin-3-ylidene)thiosemicarbazide
The title compound, C17H16N4OS, is stabilized in the form of a two-dimensional polymeric network due to intermolecular N—H⋯S and N—H⋯O hydrogen bonds. An intramolecular N—H⋯N hydrogen bond forms an S(5) ring, whereas interactions of the N—H⋯O and C—H⋯S types complete S(6) ring motifs. π–π interactions with a centroid–centroid distance of 3.6514 (10) Å are found between the ethyl-substituted benzene ring and the heterocyclic ring of the isatin derivative
Source apportionment of arsenic in atmospheric dust fall out in an urban residential area, Raipur, Central India
The components and quantities of atmospheric dust fallout have been reported to be the pollution indicator of large urban areas. The multiplicity and complexity of sources of atmospheric dusts in urban regions has put forward the need of source apportionment of these sources indicating their contribution to specific environmental receptor. The study presented here is focused on investigation of source contribution estimates of Arsenic in urban dust fallout in an urban-industrial area, Raipur, India. Source-receptor based representative sampling plan using longitudinal study design has been adopted. Six sampling sites have been identified on the basis of land use for development plan of anthropogenic activities and factors related to the transportation and dispersion pattern of atmospheric dusts. Source apportionment has been done using Chemical Mass Balance (CMB 8). Good fit parameters and relative source contribution has been analyzed and documented. Dominance of coal fired industries sources on arsenic levels measured at selected ambient residential receptors compared to line sources has been observed. Road-traffic has shown highest contribution of dust at indoor houses and out door-street automobile exhaust has shows highest contribution for arsenic. The results of CMB output and regression data of source-receptor dust matrices have shown comparable pattern
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