National Bureau ot Standards Library, £01 Admin. Bldg. FEB 3 1969 A11102 mbQQb NSRDS-NBS 20 All 1021 46006 /NSflOS-MI? N6S-.UB-CW NBS PUBLICATIONS Gas Phase Reaction Kinetics Of Neutral Oxygen Species U.S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS National Standard Reference Data Series National Bureau of Standards National Standard Reference Data System, Plan of Operation, NSRDS-NBS 1 — 15 cents* Thermal Properties of Aqueous Uni-univalent Electrolytes, NSRDS-NBS 2 — 45 cents* Selected Tables of Atomic Spectra, Atomic Energy Levels and Multiplet Tables — Si II, Si III, Si IV, NSRDS-NBS 3, Section 1 — 35 cents* Selected Tables of Atomic Spectra, Atomic Energy Levels and Multiplet Tables — Si I, NSRDS-NBS 3, Section 2 — 20 cents* Atomic Transition Probabilities, Volume I, Hydrogen Through Neon, NSRDS-NBS 4 — $2.50* The Band Spectrum of Carbon Monoxide, NSRDS-NBS 5 — 70 cents* Tables of Molecular Vibrational Frequencies, Part 1, NSRDS-NBS 6 — 40 cents* High Temperature Properties and Decomposition of Inorganic Salts, Part 1, Sulfates, NSRDS-NBS 7-35 cents* Thermal Conductivity of Selected Materials, NSRDS-NBS 8 — 11.00* Tables of Bimolecular Gas Reactions, NSRDS-NBS 9 — $2.00* Selected Values of Electric Dipole Moments for Molecules in the Gas Phase, NSRDS- NBS 10-40 cents* Tables of Molecular Vibrational Frequencies, Part 2, NSRDS-NBS 11 — 30 cents* Tables for the Rigid Asymmetric Rotor: Transformation Coefficient for Symmetric to Asymmetric Bases and Expectation Values of P§, P|, and Pf, NSRDS-NBS 12 — 60 cents* Hydrogenation of Ethylene on Metallic Catalysts, NSRDS-NBS 13 — $1.00* X-Ray Wavelengths and X-Ray Atomic Energy Levels, NSRDS-NBS 14 — 40 cents* Molten Salts: Volume 1, Electrical Conductance, Density, and Viscosity Data, NSRDS- NBS 15 — In press Thermal Conductivity of Selected Materials, NSRDS-NBS 16 — $2.00* Tables of Molecular Vibrational Frequencies, Part 3, NSRDS-NBS 17 — 30 cents* Critical Analysis of the Heat-Capacity Data of the Literature and Evaluation of Thermo- dynamic Properties of Copper, Silver, and Gold from 0 to 300 °K, NSRDS-NBS 18 — 40 cents* Thermodynamic Properties of Ammonia as an Ideal Gas, NSRDS-NBS 19 — 20 cents* *Send orders with remittance to: Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Remittances from foreign countries should include an additional one-fourth of the purchase price for postage. UNITED STATES DEPARTMENT OF COMMERCE C. R. Smith, Secretary, NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director Gas Phase Reaction Kinetics of Neutral Oxygen Species Harold S. Johnston University of California, Berkeley, California 94720 This research was supported by the Advanced Research Projects Agency of the Department of Defense under Project DEFENDER NSRDS-NBS 20 — S • National Standard Reference Data Series National Bureau of Standards Issued September 1968 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20102 • Price 45 cents Foreword The National Standard Reference Data System is a Government-wide effort to provide for the technical community of the United States effective access to the quantitative data of physical science, critically evaluated and compiled for convenience, and readily accessible through a variety of distribution channels. The System was established in 1963 by action of the President’s Office of Science and Technology and the Federal Council for Science and Technology. The responsibility to administer the System was assigned to the National Bureau of Stand- ards and an Office of Standard Reference Data was set up at the Bureau for this purpose. Since 1963, this Office has developed systematic plans for meeting high-priority needs for reliable ref- erence data. It has undertaken to coordinate and integrate existing data evaluation and compilation activities (primarily those under sponsorship of Federal agencies) into a comprehensive program, supplementing and expanding technical coverage when necessary, establishing and maintaining standards for the output of the participating groups, and providing mechanisms for the dissemina- tion of the output as required. The System now comprises a complex of data centers and other activities, carried on in Government agencies, academic institutions, and nongovermental laboratories. The independent operational status of existing critical data projects is maintained and encouraged. Data centers that are components of the NSRDS produce compilations of critically evaluated data, critical reviews of the state of quantitative knowledge in specialized areas, and computations of useful functions derived from standard reference data. In addition, the centers and projects establish criteria for evaluation and compilation of data and make recommendations on needed modifications or extensions of experimental techniques. Data publications of the NSRDS take a variety of physical forms, including books, pamphlets, loose-leaf sheets and computer tapes. While most of the compilations have been issued by the Government Printing Office, several have appeared in scientific journals. Under some circum- stances, private publishing houses are regarded as appropriate primary dissemination mechanisms. The technical scope of the NSRDS is indicated by the principal categories of data compila- tion projects now active or being planned: nuclear properties, atomic and molecular properties, solid state properties, thermodynamic and transport properties, chemical kinetics, colloid and surface properties, and mechanical properties. An important aspect of the NSRDS is the advice and planning assistance which the National Research Council of the National Academy of Sciences-National Academy of Engineering pro- vides. These services are organized under an overall Review Committee which considers the program as a whole and makes recommendations on policy, long-term planning, and international collaboration. Advisory Panels, each concerned with a single technical area, meet regularly to examine major portions of the program, assign relative priorities, and identify specific key prob- lems in need of further attention. For selected specific topics, the Advisory Panels sponsor sub- panels which make detailed studies of users’ needs, the present state of knowledge, and existing data resources as a basis for recommending one or more data compilation activities. This assembly of advisory services contributes greatly to the guidance of NSRDS activities. The NSRDS-NBS series of publications is intended primarily to include evaluated reference data and critical reviews of long-term interest to the scientific and technical community. A. V. Astin, Director. in Preface Now that chemical kinetics is approaching a certain level of maturity, with some of the field passing from frontline research to established applied science, its quantitative data should be tabulated in handbooks. Decisions must be made as to what to tabulate; suggestions have in- cluded: Empirical rate constants with defined order and regardless of mechanism, parameters of the Arrhenius equation or parameters of activated-complex theory, nothing but molecular transition probabilities or cross sections for identified changes of quantum states. The position taken in this review is that we should tabulate individual rate constants for elementary chemical reactions. I oppose basing handbooks on the other proposals listed above for the following reasons: Empirical rate data for an unanalyzed complex reaction are analogous to empirical thermodynamic data for an impure unanalyzed substance; the data may be useful for the case in hand but of no general interest. The bare reporting of parameters of the Arrhenius equation or activated-complex theory equation conceals the source of the numbers, the probable error, the relationship to other investigations. In tables of data of this sort one entry may represent an average of several hundred observed points as obtained by a dozen different investigators over a wide temperature range, and another entry may be a wild guess by an amateur in the field or the unsupported prediction of a crude theory. A refusal to tabulate any kinetic data except fundamental, quantum-state transitions is analogous to a refusal to tabulate any thermodynamic data until they are obtained by statistical mechanics from molecular parameters. The idea of elementary chemical reactions, as opposed to complex reactions on the one hand and elementary chemical-physical reactions or elementary physical reactions on the other hand, is the main topic of section 1. A detailed discussion of each of three complex reaction systems (decomposition of O2, decomposition of O3, and isotopic exchange between oxygen species) is the subject matter of the next three sections. The fifth section gives a discussion of a theoretical problem raised by these data. The strictly handbook elements of this report are given by the tables, summarized further in tables 15, 17, and 28 and in section 6. Nonkineticists are inclined to expect greater precision from kinetic data than is really there; as a step toward correcting this misapprehension, all data are presented in figures, where the experimental scatter and range of observations are readily seen. IV Acknowledgment An extensive set of reprints supplied by the Chemical Kinetics Information Center, National Bureau of Standards, permitted this study to get off to a fast start. This set of reprints was checked for completeness and supplemented by a literature search carried out by Frank