Elementary reaction

About: Elementary reaction is a research topic. Over the lifetime, 2972 publications have been published within this topic receiving 76110 citations.

Product-state control of bi-alkali-metal chemical reactions

Abstract: exoergicreactioncanbecompletelyturnedoff.Thispossibility is afforded by the fact that, for alkali dimers, the final states of reaction are not terribly different in energy from the reactants. Specifically,weconsidercollisionsofapairofKRbmolecules, prepared in their vibrational ground state (ν1 = ν2 = 0) and particular rotational states n1 and n2. These molecules are, in general, subject to two kinds of reactions: the formation of trimers via

Gas phase synthesis of [4]-helicene.

Abstract: A synthetic route to racemic helicenes via a vinylacetylene mediated gas phase chemistry involving elementary reactions with aryl radicals is presented. In contrast to traditional synthetic routes involving solution chemistry and ionic reaction intermediates, the gas phase synthesis involves a targeted ring annulation involving free radical intermediates. Exploiting the simplest helicene as a benchmark, we show that the gas phase reaction of the 4-phenanthrenyl radical ([C14H9]•) with vinylacetylene (C4H4) yields [4]-helicene (C18H12) along with atomic hydrogen via a low-barrier mechanism through a resonance-stabilized free radical intermediate (C18H13). This pathway may represent a versatile mechanism to build up even more complex polycyclic aromatic hydrocarbons such as [5]- and [6]-helicene via stepwise ring annulation through bimolecular gas phase reactions in circumstellar envelopes of carbon-rich stars, whereas secondary reactions involving hydrogen atom assisted isomerization of thermodynamically less stable isomers of [4]-helicene might be important in combustion flames as well.

Laser Induced Fluorescence Studies on C2O and CH Radicals

Abstract: C2O and CH radicals were quantitatively analysed by LIF in the reaction systems C3O2 + O + H and C2H2 + O + H. The measurements of rate constants and products of the reaction C2O + O as well as C2O + H have been carried out by excimer laser pulse photolysis for the production and by LIF for the detection of the radicals. The results give a basis of a new interpretation of the C2H2 + O + H atom flame system.

Partial oxidation of ethanol to acetaldehyde over LaMnO3-based perovskites: A kinetic study

Abstract: A set of experiments was carried out in a continuous fixed-bed reactor to investigate the relative catalytic activities of LaMnO3 and LaMn0.95Pd0.05O3 for the partial oxidation of ethanol to acetaldehyde. Both catalysts were prepared by the sol–gel method. The resultant data have indicated that LaMn0.95Pd0.05O3 is more active than LaMnO3 and that acetaldehyde selectivities of both are close at around 90%. To gain an in-depth understanding of perovskite’s chemistry involved, kinetic analysis of the data has been conducted with the differential method. Accordingly, eight elementary reactions have been proposed by resorting to the Mars–van Krevelen redox cycle. Subsequently, these elementary reactions have been lumped into five steps comprising ethanol adsorption, oxygen adsorption, surface reaction, acetaldehyde desorption, and water desorption. This has rendered it possible to derive a set of rate equations based on the Langmuir–Hinshelwood–Hougen–Watson formalism. The exploration of these rate equations h...