Results 1 - 10 of 59701
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[en] Gas-phase interaction of CT3+ (tritritium-methyl-cation) with methylalkyl-ketones of a general formula CH3COR, where R=CH3, C2H5, C3H7, C4H9, is studied. The reactions resultes in production of tritiated methanol, ethane, propene. Besides, small quantities of autaldehyde, formaldehyde, acetone and water, as well as initial labelled ketones, are formed. The transformation schemes are considered. The method of gas radiochromatography has been used to determine the yields of the reaction products
[en] As a result of reactions of biscyclopentadienyl molybden-dihalides (Cp2MoX2, X=Cl, Br or I) with tert.-butyl hydroperoxide, tert.-butylperoxides of biscyclopentadienyl molybdendichloride and-dibromide are synthesized for the first time, which are characterized by physico-chemical properties. Cyclohexene in the reaction mixture of Cp2MoX2 with tert -butyl hydroperoxide is oxidated to form cyclohexene oxide, the reaction proceeding at a high rate and with a quantitative yield. Tert.-butylperoxide of biscyclopentadienyl molybdendihalide is responsible for the cyclohexene epoxidation reaction. The schemes for the mechanism of Cp2MoX2 reactions with tert.-butyl hydroperoxide in the absence and presence of olefine are suggested
[en] The reaction between nitrous acid and hydrazine is a normal N-nitrosation reaction, and does not involve oxidation at NH2NH2 to N2H2 as previously postulated. The N-nitrosohydrazine decomposes by two parallel routes, to HN3 at high acidities and to ammonia and N2O at low acidities. An intermediate in the decomposition has been detected spectrophotometrically. Revised values are provided for the relative reactivity of some nucleophiles to nitrosating agents, and the relation between reactivity and charge in nitrosation reactions is discussed. (author)
[en] Mechanisms have been established for the state-to-state reaction O+(4S/sub u/) + N2(chi1Σ/sub g/+) → N(4S/sub u/) + NO+(chi1Σ+) + 1.1 eV in terms of potential energy hypersurface characteristics for the relevant N2O+ electronic states. The surface characteristics are established from ab initio excitation energy calculations at 1800 and 1300 along with limited scans of the 14A'', potential energy hypersurface. From these results and orbital considerations, adiabatic correlation diagrams are drawn, with emphasis on the quartet states, for C/sub infinity upsilon/ and C/sub s/ symmetry. The main mechanism is then shown to be adiabatic reaction governed by the potential energy hypersurface of the N2O+ 14A'' state. The energy barrier and the extended value of R*/sub NN/ relative to the outer anharmonic turning point for N2(upsilon), upsilon = 0 or upsilon = 1, 1.15, or 1.18 A, require that reaction on the 14A'' hypersurface exhibit ''threshold'' behavior for either translational or vibrational excitation of the reagents. It is also established that the N2O+ quartet states above 14A'' play a net negative role--collisions reaching them tend to yield products other than N(4S/sub u/) + NO+(chi1Σ+). A low-energy multistate mechanism is also shown to be possible for this state-to-state reaction. The 14A''(N2--O)+ polarization state is shown to have an equilibrium geometry (R/sub NN//sup e/, R/sub NO//sup e/, A/sub NNO//sup e/) = (1.10 +- 0.01 A, 2.35 +- 0.10 A, 1800) with a binding energy D0(N2--O+) = 0.48 +- 0.1 eV and k(N2--O+) = 0.33 +- 0.05 mdyn/A
[en] The experiments of reforming the methane of coke-oven gas with steam were performed. The effects of the thermodynamic factors, such as the H2O/CH4 ratio, the conversion temperature (T) of methane and the reaction time (t), on the methane conversion rate have been investigated. The experimental results show that the H2O/CH4 ratio within the range of 1.1-1.3 and the temperature 1223-1273 K are the reasonable thermodynamic conditions for methane conversion. A methane conversion of more than 95% can be achieved when the H2O/CH4 ratio is 1.2, the conversion temperature is above 1223 K and the conversion time is up to 15 s respectively. In additional, kinetic data of different reaction conditions were measured, and a dynamic model of methane conversion was proposed and verified. All results demonstrated that the results of the dynamic models agree well with the experiments, of which the deviation is less than 1.5%.