176 resultados para BENZENE
Resumo:
In the title compound, C12H10FN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 74.55 (2) and 11.50 (3)degrees, respectively. The structure shows a number of N - H center dot center dot center dot N intermolecular hydrogen-bonding interactions, and weak C - H center dot center dot center dot S intra- and intermolecular interactions.
Resumo:
In the title compound, C-18(14)3(3)H(FN)O, the dihedral angles made by the triazole ring with the plane of the central benzene ring and the p-fluorophenylcarbonyl group are 82.09 ( 2) and 82.05 (2), respectively. There are weak C-H...O intra- and intermolecular interactions in the crystal structure, which contribute to the stability.
Resumo:
In the title compound, C21H16N4OS, the dihedral angles between the planes of the benzotriazole and N-phenyl rings and the plane of the atoms that link these two rings are 79.56 (6) and 59.02 (5) degrees, respectively, while that between the two benzene rings is 64.12 (6) degrees. There are some inter- and intramolecular interactions in the crystal structure.
Resumo:
In the title compound, C12H10ClN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 73.57 (3) and 46.65 (2)degrees, respectively. Inter-and intramolcular hydrogen bonds and pi-pi stacking interactions stabilize the structure.
Resumo:
In the title compound, C12H10FN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 71.94 (3) and 40.10 (2)degrees, respectively. Inter- and intramolecular hydrogen-bond and pi-pi stacking interactions stabilize the structure.
Resumo:
The inhibition effect of nicotinic acid for corrosion of hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid was investigated using quantum chemistry analysis, weight loss test, electrochemical measurement, and scanning electronic microscope (SEM) analysis. Quantum chemistry calculation results showed that nicotinic acid possessed planar structure with a number of active centers, and the populations of the Mulliken charge, the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) were found mainly focused around oxygen and nitrogen atoms, and the cyclic of the benzene as well. The results of weight loss test and electrochemical measurement indicated that inhibition efficiency (IE%) increased with inhibitor concentration, and the highest inhibition efficiency was up to 96.7%. The corrosion inhibition of these coatings was discussed in terms of blocking the electrode reaction by adsorption of the molecules at the active centers on the electrode surface. It was found that the adsorption of nicotinic acid on coating surface followed Langmuir adsorption isotherm with single molecular layer, and nicotinic acid adsorbed on the coating surface probably by chemisorption. Nicotinic acid, therefore, can act as a good nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid solution. (c) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Four main methods, such as weight loss test, EIS, adsorption isotherm and quantum chemical calculation were employed to study the inhibition efficiency and mechanism of three derivatives on mild steel in acid solution, whose inhibition efficiency were proved to follow the order of DMTT > NMTT > PMTT, The adsorption model of DMTT was established at different temperature according to the fitted results. The quantum chemical results indicated that the adsorption sites of the derivatives were strongly centralized on benzene ring, triazole ring, etc. QSAR was set up to explain the relationship of molecular structure and the inhibition effect of the derivatives. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Natural gas pays more important role in the society as clean fuel. Natural gas exploration has been enhanced in recent years in many countries. It also has prospective future in our country through "85" and "95" national research. Many big size gas fields have been discovered in different formations in different basins such as lower and upper Paleozoic in Erdos basin, Tertiary system in Kuche depression in Tarim basin, Triassic system in east of Sichuan basin. Because gas bearing basins had been experienced multiple tectogenesis. The characteristics of natural gases usually in one gas field are that they have multiple source rocks and are multiple maturities and formed in different ages. There has most difficult to research on the gas-rock correlation and mechanism of gas formation. Develop advanced techniques and methods and apply them to solve above problems is necessary. The research is focused on the critical techniques of geochemistry and physical simulation of gas-rock correlation and gas formation. The lists in the following are conclusions through research and lots of experiments. I 8 advanced techniques have been developed or improved about gas-rock correlation and gas migration, accumulation and formation. A series of geochemistry techniques has been developed about analyzing inclusion enclave. They are analyzing gas and liquid composition and biomarker and on-line individual carbon isotope composition in inclusion enclave. These techniques combing the inclusion homogeneous temperature can be applied to study on gas-rock correlation directly and gas migration, filling and formation ages. Technique of on-line determination individual gas carbon isotope composition in kerogen and bitumen thermal pyrolysis is developed. It is applied to determine the source of natural is kerogen thermal degradation or oil pyrolysis. Method of on-line determination individual gas carbon isotope composition in rock thermal simulation has being improved. Based on the "95"former research, on-line determination individual gas carbon isotope composition in different type of maceral and rocks thermal pyrolys is has been determined. The conclusion is that carbon isotope composition of benzene and toluene in homogenous texture kerogen thermal degradation is almost same at different maturity. By comparison, that in mixture type kerogen thermal pyrolysis jumps from step to step with the changes of maturity. This conclusion is a good proof of gas-rock dynamic correlation. 3. Biomarker of rock can be determined directly through research. It solves the problems such as long period preparing sample, light composition losing and sample contamination etc. It can be applied to research the character of source rock and mechanism of source rock expulsion and the path of hydrocarbon migration etc. 4. The process of hydrocarbon dynamic generation in source rock can be seen at every stage applying locating observation and thermal simulation of ESEM. The mechanism of hydrocarbon generation and expulsion in source rock is discussed according to the experiments. This technique is advanced in the world. 5. A sample injection system whose character is higher vacuum, lower leaks and lower blank has been built up to analyze inert gas. He,Ar,Kr and Xe can be determined continuously on one instrument and one injection. This is advanced in domestic. 7. Quality and quantity analysis of benzene ring compounds and phenolic compounds and determination of organic acid and aqueous gas analysis are applied to research the relationship between compounds in formation water and gas formation. This is another new idea to study the gas-rock correlation and gas formation. 8. Inclusion analysis data can be used to calculate the Paleo-fluid density, Paleo-geothermal gradient and Paleo-geopressure gradient and then to calculate the Paleo-fluid potential. It's also a new method to research the direction of hydrocarbon migration and accumulation. 9. Equipment of natural gas formation simulation is produced during the research to probe how the physical properties of rock affect the gas migration and accumulation and what efficiency of gas migrate and factors of gas formation and the models of different type of migration are. II study is focused on that if the source rocks of lower Paleozoic generated hydrocarbon and what the source rocks of weathered formation gas pool and the mechanism of gas formation are though many advanced techniques application. There are four conclusions. 1.The maturity of Majiagou formation source rocks is higher in south than that in north. There also have parts of the higher maturity in middle and east. Anomalous thermal pays important role in big size field formation in middle of basin. 2. The amount of gas generation in high-over maturity source rocks in lower Paleozoic is lager than that of most absorption of source rocks. Lower Paleozoic source rocks are effective source rocks. Universal bitumen exists in Ordovician source rocks to prove that Ordovician source rocks had generated hydrocarbon. Bitumen has some attribution to the middle gas pool formation. 3. Comprehensive gas-rock correlation says that natural gases of north, west, south of middle gas field of basin mainly come from lower Paleozoic source rocks. The attribution ratio of lower Paleozoic source rocks is 60%-70%. Natural gases of other areas mainly come from upper Paleozoic. The attribution ratio of upper Paleozoic source rocks is 70%. 4. Paleozoic gases migration phase of Erdos basin are also interesting. The relative abundance of gasoline aromatic is quite low especially toluene that of which is divided by that of methyl-cyclohexane is less than 0.2 in upper Paleozoic gas pool. The migration phase of upper Paleozoic gas may be aqueous phase. By comparison, the relative abundance of gasoline aromatic is higher in lower Paleozoic gas. The distribution character of gasoline gas is similar with that in source rock thermal simulation. The migration phase of it may be free phase. IH Comprehensive gas-rock correlation is also processed in Kuche depression Tarim basin. The mechanism of gas formation is probed and the gas formation model has been built up. Four conclusions list below. 1. Gases in Kuche depression come from Triassic-Jurassic coal-measure source rocks. They are high-over maturity. Comparatively, the highest maturity area is Kelasu, next is Dabei area, Yinan area. 2. Kerogen thermal degradation is main reason of the dry gas in Kuche depression. Small part of dry gas comes from oil pyrolysis. VI 3.The K12 natural gas lays out some of hydro-gas character. Oil dissolved in the gas. Hydro-gas is also a factor making the gas drier and carbon isotope composition heavier. 4. The mechanism and genesis of KL2 gas pool list as below. Overpressure has being existed in Triassic-Jurassic source rocks since Keche period. Natural gases were expulsed by episode style from overpressure source rocks. Hetero-face was main migration style of gas, oil and water at that time. The fluids transferred the pressure of source rocks when they migrated and then separated when they got in reservoir. After that, natural gas migrated up and accumulated and formed with the techno-genesis. Tectonic extrusion made the natural gas overpressure continuously. When the pressure was up to the critical pressure, the C6-C7 composition in natural gas changed. The results were that relative abundance of alkane and aromatic decreased while cycloalkane and isoparaffin increased. There was lots of natural gas filling during every tectonic. The main factors of overpressure of natural gas were tectonic extrusion and fluid transferring pressure of source rocks. Well preservation was also important in the KL2 gas pool formation. The reserves of gas can satisfy the need of pipeline where is from west to east. IV A good idea of natural gas migration and accumulation modeling whose apparent character is real core and formation condition is suggested to model the physical process of gas formation. Following is the modeling results. 1. Modeling results prove that the gas accumulation rule under cap layer and gas fraction on migration path. 2. Natural gas migration as free phase is difficult in dense rock. 3. Natural gases accumulated easily in good physical properties reservoirs where are under the plugging layer. Under the condition of that permeability of rock is more than 1 * 10~(-3)μm~(-1), the more better the physical properties and the more bigger pore of rock, the more easier the gas accumulation in there. On the contrary, natural gas canonly migrate further to accumulate in good physical properties of rock. 4. Natural gas migrate up is different from that down. Under the same situation, the amount of gas migration up is lager than that of gas migration down and the distance of migration up is 3 times as that of migration down. 5. After gas leaks from dense confining layer, the ability of its dynamic plug-back decreased apparently. Gas lost from these arils easily. These confining layer can confine again only after geology condition changes. 6. Water-wetted and capillary-blocking rocks can't block water but gases generally. The result is that water can migrate continuously through blocking rocks but the gases stay under the blocking rocks then form in there. The experiments have proved the formation model of deep basin gas.
Resumo:
The catalytic behavior of Mo-based zeolite catalysts with different pore structure and size, particularly with 8 membered ring ( M R), 10 M R, coexisted 10 and 12 M R, and 12 M R, was studied in methane aromatization under the conditions of SV=1500 ml/(g.h), p=0.1 MPa and T = 973 K. It was found that the catalytic performance is correlated with the pore structure of the zeolite supports. The zeolites that possess 10 MR or 10 and 12 MR pore structure with a pore diameter equal to or slightly larger than the dynamic diameter of benzene molecule, such as ZSM-5, ZSM-11, ZRP-1 and MCM-22, are fine supports. Among the tested zeolite supports, MCM-22 exhibits the highest activity and selectivity for benzene. A methane conversion of 10.5% with benzene selectivity of 80% was achieved over Mo/MCM-22 catalyst. The Mo/ERS-7 catalyst with 8 MR (0.45 nm) does not show any activity in methane dehydro-aromatization, while Mo/JQX-1 and Mo/SBA-15 catalysts with 12 MR pore exhibit little activity in the reaction. It can be concluded that the zeolites with 10 MR pore or coexisted 10 and 12 MR, having pore size equal to or slightly larger than the dynamic diameter of benzene molecule, are fine supports for methane activation and aromatization.
Resumo:
The acid properties of Mo/HMCM-22 catalyst, which is the precursor form of the working catalyst for methane aromatization reaction, and the synergic effect between Mo species and acid sites were studied and characterized by various characterization techniques. It is concluded that Bronsted and Lewis acidities of HMCM-22 are modified due to the introduction of molybdenum. We suggest a monomer of Mo species is formed by the exchange of Mo species with the Bronsted acid sites. On the other hand, coordinate unsaturated sites (CUS) are suggested to be responsible for the formation of newly detected Lewis acid sites. Computer modelling is established and coupling with experimental results, it is then speculated that the effective activation of methane is properly accomplished on Mo species accommodated in the 12 MR supercages of MCM-22 zeolite whereas the Bronsted acid sites in the same channel system play a key role for the formation of benzene. A much more pronounced volcano-typed reactivity curve of the Mo/HMCM-22 catalysts, as compared with that of the Mo/HZSM-5, with respect to Mo loading is found and this can be well understood due to the unique channel structure of MCM-22 zeolite and synergic effect between Mo species and acid sites.
Resumo:
We have investigated the relationship between the molecular configuration and dipole moment of some fluorinated liquid crystals (LCs). The aeornetries of the molecules were preliminarily optimized at empirical AM1 and then were further optimized at B3LYP/6-31G(d) level. The dipole moment has been calculated. It is strongly influenced by the position and number of fluorine substituents in the benzene ring of the molecule. The polarizability, mean polarizabilities, and anisotropic polarizability of the phenylbicyclohexane (PBC) fluorine substituents are also given and discussed. (c) 2004 Wiley Periodicals, Inc.