β-Ionone reactions with the nitrate radical: Rate constant and gas-phase products

✍ Scribed by Joel C. Harrison; Jason E. Ham

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 374 KB
• Volume: 41
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20438

✦ Synopsis

Abstract

The bimolecular rate constant of k (9.4 ± 2.4 × 10^−12^ cm^3^ molecule^−1^ s^−1^ was measured using the relative rate technique for the reaction of the nitrate radical (NO~3~•) with 4‐(2,6,6‐trimethyl‐1‐cyclohexen‐1‐yl)‐3‐buten‐2‐one (β‐ionone) at (297 ± 3) K and 1 atmosphere total pressure. In addition, the products of β‐ionone + NO~3~• reaction were also investigated. The identified reaction products were glyoxal (HC(O)C(O)H), and methylglyoxal (CH~3~C(O)C(O)H). Derivatizing agents O‐(2,3,4,5,6‐pentafluorobenzyl)hydroxylamine and N,O‐bis(trimethylsilyl)trifluoroacetamide were used to propose the other major reaction products: 3‐oxobutane‐1,2‐diyl nitrate, 2,6,6‐trimethylcyclohex‐1‐ene‐carbaldehyde, 2‐oxo‐1‐(2,6,6‐trimethylcyclohex‐1‐en‐1‐yl)ethyl nitrate, pentane‐2,4‐dione, 3‐oxo‐1‐(2,6,6‐trimethylcyclohex‐1‐en‐1‐yl)butane‐1,2‐diyl dinitrate, 3,3‐dimethylcyclohexane‐1,2‐dione, and 4‐oxopent‐2‐enal. The elucidation of these products was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible β‐ionone + NO~3~• reaction mechanisms based on previously published volatile organic compound + NO~3~• gas‐phase mechanisms. The additional gas‐phase products 5‐acetyl‐2‐ethylidene‐3‐methylcyclopentyl nitrate, 1‐(1‐hydroxy‐7,7‐dimethyl‐2,3,4,5,6,7‐hexahydro‐1 H‐inden‐2‐yl)ethanone, 1‐(1‐hydroxy‐3__a__,7‐dimethyl‐2,3,3__a__,4,5,6,‐hexahydro‐1 H‐inden‐2‐yl)ethanone, and 5‐acetyl‐2‐ethylidene‐3‐methylcyclopentanone are proposed to be the result of cyclization through a reaction intermediate. © 2009 Wiley Periodicals, Inc.*This article is a U.S. Government work and, as such, is in the public domain of the United States of America.

Int J Chem Kinet 41: 629–641, 2009