Development of revised SAPRC aromatics mechanisms

The capability of various high-level DFT and ab initio MO methods to predict molecular and energetic parameters has been critically tested for the OH radical reaction with benzene G3 theory proved to be the most accurate in estimating reaction barriers and enthalpies For the first time, the molecular structure, stabilization energy and nature of the bonding interactions of the [C6H6···OH] prereaction complex have been characterized Accurate thermochemistry for major reaction channels was established by making combined use of experimental and theoretical parameters A multistep kinetic model for the OH-addition channel was proposed, and the effects of T, P, and reaction time on the apparent rate constants were evaluated by weak collision master equation/RRKM analysis Available experimental kinetic data for all relevant reactions are critically analyzed and correlated with modeled effective rate constants

Kinetics and mechanism of the OH + C6H6 reaction: A detailed analysis with first-principles calculations

Rate constants for the gas‐phase reactions of OH radicals with a series of unsaturated alcohols

Using a relative rate method, rate constants have been determined at 296 ± 2 K for the gas-phase reactions of the OH radical with toluene, the xylenes, and the trimethylbenzenes. Using the recommended literature rate constant for the reaction of OH radicals with propene of (2.66 ± 0.40) × 10−11 cm3 molecule−1 s−1, the following rate constants (in units of 10−12 cm3 molecule−1 s−1) were obtained: toluene, 5.48 ± 0.84; o-xylene, 12.2 ± 1.9; m-xylene, 23.0 ± 3.5; p-xylene, 13.0 ± 2.0; 1,2,3-trimethylbenzene, 32.7 ± 5.3; 1,2,4-trimethylbenzene, 32.5 ± 5.0; and 1,3,5-trimethylbenzene, 57.5 ± 9.2. These data are compared with the literature values.

Rate constants for the gas‐phase reactions of the OH radical with a series of aromatic hydrocarbons at 296 ± 2 K

DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A Toxicological Profile for Ethylbenzene, Draft for Public Comment was released in October 2007. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: FOREWORD This toxicological profile is prepared in accordance with guidelines* developed by the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA). The original guidelines were published in the Federal Register on April 17, 1987. Each profile will be revised and republished as necessary. The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects infonnation for these toxic substances described therein. Each peer-reviewed profile identifies and reviews the key literature that describes a substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies. The profile is not intended to be an exhaustive document; however, more comprehensive sources of specialty information are referenced. The focus of the profiles is on health and toxicologic infonnation; therefore, each toxicological profile begins with a public health statement that describes, in nontechnical language, a substance's relevant toxicological properties. Following the public health statement is infonnation concerning levels of significant human exposure and, where known, significant health effects. The adequacy of infonnation to detennine a substance's health effects is described in a health effects summary. Data needs that are of significance to protection of public health are identified by ATSDR. Each profile includes the following: (A) The examination, summary, and interpretation of available toxicologic infonnation and epidemiologic evaluations on a toxic substance to ascertain the levels of significant human exposure for the substance and the associated acute, subacute, and chronic health effects; (B) A determination of whether adequate infonnation on the health effects of each substance is available or in the process of development to detennine levels of exposure that present a significant risk to human health of acute, subacute, and chronic health effects; and (C) Where appropriate, identification of toxicologic testing needed to identifY the types or levels of exposure that may present significant risk of adverse health effects in humans. The principal audiences for the toxicological profiles are health professionals at the Federal, State, and local levels; …

Toxicological profile for ethylbenzene

The rate constants for the reactions of OH radicals with seventeen aromatic hydrocarbons were determined at atmospheric pressure and room temperature from competitive reactions with hexane, using H2O2 as the OH-radical source. A useful trend was found in the structure-reactivity relationship.

Toshiro Ohyama

Papers

A Set of Rate Constants for the Reactions of OH Radicals with Aromatic Hydrocarbons