Simulation of reactions of fluoroalkenes by quantum chemistry methods

Abstract

The indium activation diagnostic was calibrated using an accelerator neutron source to facilitate the diagnosis of deuterium-deuterium (DD) neutron yields of implosion experiments in the Shenguang-III facility. The scattered neutron background of the accelerator room was measured by placing a polypropylene shadow bar in front of the indium sample, so as to correct the calibrated factor of this activation diagnostic. The proper size of the shadow bar was given by Monte Carlo simulation. The calibration results showed that the scattered neutron background of the accelerator room was about 9% of the incident neutrons on the sample. Subtracting the portion induced by the neutron background, the calibrated factor for this sample condition was 4.52×10 -7 counts/n with an uncertainty of 4.3%.

Diastereoselective Diels−Alder Reactions of α-Fluorinated α,β-Unsaturated Carbonyl Compounds: Chemical Consequences of Fluorine Substitution. 2

“…Actually, there is little knowledge concerning the effect of a single fluorine substituent on the electronic properties, the stability, and the reactivity of the π-system of simple vinyl fluorides. ,, These studies revealed significant differences in reactivity compared both to nonfluorinated and higher fluorinated olefins. Only fluoroethylene itself and several of its substituted derivatives have been investigated by experimental and theoretical methods, showing that there is a weak influence of a single fluorine substituent. Investigations of fluoroethylene by means of photoelectron and electron transmission spectroscopy show the ability of the fluorine substituent to exert p−π-interaction (+M effect) on the double bond .…”

“…2-Fluoropropene has been treated in ab initio calculations to show that there is a +M effect of fluorine, but this interaction was considered less significant compared to the −I effect . Ab initio calculations of fluoroethylene and ethylene revealed the LUMO and HOMO energy of the first compound to be lowered slightly (0.09 and 0.21 eV) compared to ethylene,12d suggesting that fluorine acts as a weak electron acceptor. However, the ionization energy of vinyl fluoride is only 0.14 eV higher than that of ethylene, proving a weak interaction of the π-bond with the 2p-orbital of the fluorine atom .…”