Measurements and automated mechanism generation modeling of OH production in photolytically initiated oxidation of the neopentyl radical

Sarah V Petway; Huzeifa Ismail; William H Green; Edgar G Estupiñan; Leonard E Jusinski; Craig A Taatjes

doi:10.1021/jp0668549

Measurements and automated mechanism generation modeling of OH production in photolytically initiated oxidation of the neopentyl radical

J Phys Chem A. 2007 May 17;111(19):3891-900. doi: 10.1021/jp0668549. Epub 2007 Apr 18.

Authors

Sarah V Petway¹, Huzeifa Ismail, William H Green, Edgar G Estupiñan, Leonard E Jusinski, Craig A Taatjes

Affiliation

¹ Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

PMID: 17439192
DOI: 10.1021/jp0668549

Abstract

Production of OH in the reaction of the neopentyl radical with O2 has been measured by a laser photolysis/cw absorption method for various pressures and oxygen concentrations at 673, 700, and 725 K. The MIT Reaction Mechanism Generator (RMG) was used to automatically generate a model for this system, and the predicted OH concentration profiles are compared to present and literature experimental results. Several reactions significantly affect the OH profile. The experimental data provide useful constraints on the rate coefficient for the formally direct chemical activation reaction of neopentyl radical with O2 to form OH (CH3)3CCH2 + O2 --> OH + 3,3-dimethyloxetane (Rxn 1) At 673 K and 60 Torr, log k(1) (cm(3) molecule(-1) s(-1)) = -13.7 +/- 0.5. Absolute absorbance measurements on OH and I indicate that the branching ratio for R + O2 to OH is about 0.03 under these conditions. The data suggest that the ab initio neopentyl + O2 potential energy surface of Sun and Bozzelli is accurate to within 2 kcal mol(-1).