Thumbnail
Access Restriction
Open

Author Abbatt, J. P. D. ♦ Toohey, D. W. ♦ Fenter, F. F. ♦ Stevens, P. S. ♦ Brune, W. H. ♦ Anderson, J. G.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ ENVIRONMENTAL SCIENCES ♦ BROMINE ♦ CHEMICAL REACTIONS ♦ CHLORINE ♦ FLUORINE ♦ HYDROXY COMPOUNDS ♦ NITROGEN ♦ NITROGEN COMPOUNDS ♦ OXYCHLORIDES ♦ OXYGEN ♦ ACTIVATION ENERGY ♦ AFFINITY ♦ EXPERIMENTAL DATA ♦ HIGH TEMPERATURE ♦ MEDIUM TEMPERATURE ♦ CHLORINE COMPOUNDS ♦ DATA ♦ ELEMENTS ♦ ENERGY ♦ HALOGEN COMPOUNDS ♦ HALOGENS ♦ INFORMATION ♦ NONMETALS ♦ NUMERICAL DATA ♦ ORGANIC COMPOUNDS ♦ OXYGEN COMPOUNDS ♦ OXYHALIDES ♦ Chemical & Physicochemical Properties
Abstract The rate constants for a series of radical reactions with ClNO, X + ClNO {yields} products where X = Cl, F, Br, OH, O, N, have been measured as a function of temperature in discharge flow systems at pressures between 1 and 2 Torr of helium buffer gas. Radicals were detected by resonance fluorescence (X = Cl, Br, OH, O), laser magnetic resonance (X = OH), and chemical conversion/resonance fluorescence (X = F, N). The rate constants, with units of cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} and to 95% confidence level, are for Cl + ClNO {yields} Cl{sub 2} + NO, ((6.6 {plus minus} 1.2) {times} 10{sup {minus}11}) e{sup (128{plus minus}46)/T}; for F + ClNO {yields} FCl + NO, ((1.4 {plus minus} 0.4) {times} 10{sup {minus}10}) e{sup ({minus}28{plus minus}84)/T}; for Br + ClNO {yields} BrCl + NO, ((1.5 {plus minus} 0.2) {times} 10{sup {minus}11}) e{sup ({minus}52{plus minus}43)/T}; for OH + ClNO {yields} ClOH + NO, ((9.0 {plus minus} 4.5) {times} 10{sup {minus}12}) e{sup ({minus}1130{plus minus}170)/T}; for OH + ClNO {yields} HONO + Cl, ((9.2 {plus minus} 6.5) {times} 10{sup {minus}14}) e{sup (240{plus minus}130)/T}; for O + ClNO {yields} ClO + NO, ((8.3 {plus minus} 0.9) {times} 10{sup {minus}12}) e{sup ({minus}1520{plus minus}35)/T}; and for N + ClNO {yields} NCl + NO, ((9.2 {plus minus} 2.2) {times} 10{sup {minus}12}) e{sup ({minus}2250{plus minus}90)/T}. Both the reaction activation energies and the logarithms of the room temperature rate constants are found to correlate strongly with the electron affinity of the radical in such a way that high electron affinity leads to enhanced reactivity. The reactivity trend is rationalized by a frontier orbital interaction dominated by the ease with which electron transfer from the ClNO molecule to the X radical can occur to stabilize a polar transition state, a mechanism shown to be widely prevalent in radical-molecule systems.
ISSN 00223654
Educational Use Research
Learning Resource Type Article
Publisher Date 1989-02-09
Publisher Place United States
Journal Journal of Physical Chemistry
Volume Number 93
Issue Number 3


Open content in new tab

   Open content in new tab