34467-54-4Relevant articles and documents
RELATIVE ELECTRON AFFINITIES OF SUBSTITUTED BENZOPHENONES, NITROBENZENES, AND QUINONINES
Fukuda, Elaine K.,McIver, Robert T.
, p. 2291 - 2296 (1985)
The relative electron affinities of 53 molecules have been determined by measuring equilibrium constants for gas-phase electron-transfer reactions of the general type A-. + B = B-. + A.A pulsed ion resonance (ICR) spectrometer was utilized to generate, store , and detect molecular anion radicals at pressures below 1x1E5 torr.The ions were generated by electron capture and stored for several hundred milliseconds in a one-region ICR analyzer cell.A scale relative electron affinities has been constructed by using the mode of multiple overlaps.Substituent effects on the electron affinities of various nitrobenzenes, benzophenones, and quinones are discussed.
Resonance Electron Capture Rate Constants for Substituted Nitrobenzenes
Knighton, W. B.,Mock, R. S.,McGrew, D. S.,Grimsrud, E. P.
, p. 3770 - 3776 (2007/10/02)
We report here a new method for the determination of electron capture (EC) rate constants that utilizes a pulsed electron beam mass spectrometer.The method is first tested by measurements of the known dissociative electron capture rate constants for several halogenated methanes that have been extensively studied by other techniques.The resonance electron capture (REC) rate constants of nitrobenzene (NB) and 23 substituted nitrobenzenes (SNB's) are then determined for the first time at 125 deg C in 10 Torr of methane buffer gas.The SNB's studied here include several sets of closely related structural isomers whose electron affinities (EA's) have been previously determined.It is shown that the REC rate constants of these compounds bear little systematic relationship with the EA's of these compounds.The REC rate constants of the SNB's are also compared with other previously reported characteristics associated with the negative ionization of these compounds, including their entropies of negative ionization, the lifetimes against autodetachment of their initially formed molecular anions, and the rates of autodetachment from electronically excited states of their molecular anions.
Entropy Changes and Electron Affinities from Gas-Phase Electron-Transfer Equilibria: A(-) + B = A + B(-)
Chowdhury, Swapan,Heinis, Thomas,Grimsrud, Eric P.,Kebarle, Paul
, p. 2747 - 2752 (2007/10/02)
By measuring the electron-transfer equilibria 1, A(-) + B = A + B(-), at 150 deg C with a pulsed electron high-pressure mass spectrometer we determined the ΔGo1 values involving 12 new compounds.Measurements of the temperature dependence of K1 for 21 reactions involving some of the new compounds and many compounds whose ΔGo1 had been determined previously led, via van't Hoff plots, to ΔHo1 and ΔSo1 values.These were interconnecting such that ΔHo and ΔSo continuous scales (ladders) were obtained.These were anchored to SO2 whose electron affinity is accurately known.Available geometries and vibrational frequencies for SO2 and SO2(-) permit the evaluation of So(SO2(-)) - So(SO2).Through the ΔSo scale the So(B(-)) - So(B) for the other compounds B could be obtained also.Certain regularities in the So(B(-)) - So(B) data permitted entropy estimates to be made also for compounds for which no van't Hoff plots were made.In this manner a table of ΔHo, ΔSo, and ΔGo data for the electron capture e + B = B(-) was obtained, which contains some 50 compounds B.Most of the compounds are substituted benzenes, quinones, conjugated acid anhydrides, and perfluorinated organics.
