Title: Master equation study of hydrogen abstraction from HCHO by OH via a chemically activated intermediate

Journal Article · · Faraday Discussions
DOI: https://doi.org/10.1039/d2fd00024e · OSTI ID:2420435
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [2]
  1. Tsinghua Univ., Beijing (China); OSTI
  2. Tsinghua Univ., Beijing (China)
  3. Univ. of Minnesota, Minneapolis, MN (United States)
+ Show Author Affiliations

The abstraction reaction of hydrogen from formaldehyde by OH radical plays an important role in formaldehyde oxidation. The reaction involves a bimolecular association to form a chemically activated hydrogen-bonded reaction complex followed by a unimolecular reaction of the complex to generate the products. The reaction rate is usually considered to be pressure-independent by assuming equilibrium between the reactants and the complex. However, our nonequilibrium calculations based on the chemically significant eigenmode of the master equation, carried out with our recently developed TUMME program, indicate that the reaction complex makes the rate constant dependent on pressure at low temperatures (T < 200 K). The calculations include anharmonicity, variational effects, and multi-dimensional tunneling. We find that the reaction rate constant reaches a low-pressure limit at pressures below 10 Torr over the whole investigated temperature range (20–1800 K), which explains why the available low-temperature experiments, which are for pressures below 2 Torr, did not observe the pressure dependence. A new extension of the TUMME master-equation program is used to explore the time evolutions of the concentrations of the OH radical and the complex under pseudo-first-order conditions. The time-dependent evolution of the concentrations of the complex at a low temperature provide direct evidence for the stabilization of the reaction complex at high pressures, and it shows the negligible role of the stabilized reaction complex at low pressures. Finally, the picture that emerges is qualitatively consistent with our previous study of the reaction of methanol with OH in that the tunneling in the unimolecular step from the complex to the products affects the phenomenological reaction rate constants differently at high and low pressures and leads to a significant pressure effect.

Research Organization:
Univ. of New Mexico, Albuquerque, NM (United States)
Sponsoring Organization:
National Natural Science Foundation of China (NSFC); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0015997
OSTI ID:
2420435
Journal Information:
Faraday Discussions, Journal Name: Faraday Discussions Vol. 238; ISSN 1359-6640
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English

References (59)

Multiple-Well, multiple-path unimolecular reaction systems. I. MultiWell computer program suite journal January 2001
The reaction between ethyl and molecular oxygen II: Further analysis journal January 2001
Direct measurements of the reaction OH + CH2O ? HCO + H2O at high temperatures journal January 2004
Ab initio study of the OH + CH2O reaction: The effect of the OH··OCH2 complex on the H-abstraction kinetics journal January 2006
Quantum chemical and master equation study of OH + CH 2 O → H 2 O + CHO reaction rates in supercritical CO 2 environment journal November 2018
Kinetics of hydroxyl radical reactions with formaldehyde and 1,3,5-trioxane between 290 and 600 K journal February 1988
Tunneling in enzymatic and nonenzymatic hydrogen transfer reactions journal March 2010
Theoretical investigations of molecules composed only of fluorine, oxygen and nitrogen: determination of the equilibrium structures of FOOF, (NO)2 and FNNF and the transition state structure for FNNF cis-trans isomerization journal January 1989
A fifth-order perturbation comparison of electron correlation theories journal May 1989
TUMME: Tsinghua University Minnesota Master Equation program journal January 2022
High temperature measurements for the rate constants of C1–C4 aldehydes with OH in a shock tube journal January 2015
Theoretical studies on the reactions of formaldehyde with OH and OH− journal September 2007
Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH 2 O, OH + CH 2 CH 2 , and OH + CH 2 NH journal February 2015
Kinetics of Propargyl Radical Dissociation journal February 2015
Kinetics of the Hydrogen Abstraction Reaction From 2-Butanol by OH Radical journal September 2015
Benchmark Calculations for Bond Dissociation Enthalpies of Unsaturated Methyl Esters and the Bond Dissociation Enthalpies of Methyl Linolenate journal June 2016
Computational Kinetics by Variational Transition-State Theory with Semiclassical Multidimensional Tunneling: Direct Dynamics Rate Constants for the Abstraction of H from CH 3 OH by Triplet Oxygen Atoms journal February 2017
Prediction of Rate Coefficients for the H 2 CO + OH → HCO + H 2 O Reaction at Combustion, Atmospheric and Interstellar Medium Conditions journal February 2020
The Importance of Ensemble Averaging in Enzyme Kinetics journal December 2014
Variational transition-state theory journal December 1980
Modeling the Kinetics of Bimolecular Reactions journal November 2006
Computational Thermochemistry: Scale Factor Databases and Scale Factors for Vibrational Frequencies Obtained from Electronic Model Chemistries journal August 2010
Convergent Partially Augmented Basis Sets for Post-Hartree−Fock Calculations of Molecular Properties and Reaction Barrier Heights journal December 2010
How Well Can Modern Density Functionals Predict Internuclear Distances at Transition States? journal May 2011
Perspectives on Basis Sets Beautiful: Seasonal Plantings of Diffuse Basis Functions journal August 2011
Exploring the Limit of Accuracy of the Global Hybrid Meta Density Functional for Main-Group Thermochemistry, Kinetics, and Noncovalent Interactions journal October 2008
Molecular modeling of the kinetic isotope effect for the [1,5]-sigmatropic rearrangement of cis-1,3-pentadiene journal March 1993
The Non-Equilibrium Theory of Absolute Rates of Reaction 1 journal November 1947
Chemical Kinetics and Mechanisms of Complex Systems: A Perspective on Recent Theoretical Advances journal January 2014
Low-Pressure Limit of Competitive Unimolecular Reactions journal August 2020
Kinetics of the Methanol Reaction with OH at Interstellar, Atmospheric, and Combustion Temperatures journal February 2018
Relative Rates of Hydrogen Shift Isomerizations Depend Strongly on Multiple-Structure Anharmonicity journal November 2018
From the Multiple-Well Master Equation to Phenomenological Rate Coefficients:  Reactions on a C 3 H 4 Potential Energy Surface journal April 2003
Master Equation Methods in Gas Phase Chemical Kinetics journal September 2006
Reformulation and Solution of the Master Equation for Multiple-Well Chemical Reactions journal May 2013
Molecular Modeling of Combustion Kinetics. The Abstraction of Primary and Secondary Hydrogens by Hydroxyl Radical journal September 1997
Reaction between OH and HCHO: temperature dependent rate coefficients (202–399 K) and product pathways (298 K) journal January 2003
Variational transition state theory: theoretical framework and recent developments journal January 2017
A master equation model for bimolecular reaction via multi-well isomerizing intermediates journal January 2000
Experimental and theoretical studies of gas phase NO3 and OH radical reactions with formaldehyde, acetaldehyde and their isotopomersElectronic supplementary information (ESI) available: program package FACSIMILE for simulation of the complex set of reactions and the kinetics of the reactor system. Kinetic data from the acetaldehyde studies, the spectral ranges and the compounds included in the subtraction procedures, and a full report of the statistical analyses. Calculated energies of the reactants, intermediate stationary points of the potential energy surface, and the products. Calculated vibrational wavenumbers of the reactants and transition states. See http://www.rsc.org/suppdata/cp/b2/b211234p/ journal March 2003
Practical methods for including torsional anharmonicity in thermochemical calculations on complex molecules: The internal-coordinate multi-structural approximation journal January 2011
Multi-structural variational transition state theory. Kinetics of the 1,4-hydrogen shift isomerization of the pentyl radical with torsional anharmonicity journal January 2011
Multi-path variational transition state theory for chemical reaction rates of complex polyatomic species: ethanol + OH reactions journal January 2012
Determining phenomenological rate coefficients from a time-dependent, multiple-well master equation: “species reduction” at high temperatures journal January 2013
Inversion of the Partition Function: The First‐Order Steepest‐Descent Method journal January 1970
Calculation of Statistical Complexions of Harmonic Oscillations journal September 1965
Improved Calculation of Quasiequilibrium Reaction Rate Constants journal September 1963
Simplified CCSD(T)-F12 methods: Theory and benchmarks journal February 2009
Analytic solution of relaxation in a system with exponential transition probabilities journal December 1977
Criterion of minimum state density in the transition state theory of bimolecular reactions journal February 1979
Canonical unified statistical model. Classical mechanical theory and applications to collinear reactions journal February 1982
The relationship between recombination, chemical activation and unimolecular dissociation rate coefficients journal April 1989
Generalized correlations in terms of polarizability for van der Waals interaction potential parameter calculations journal August 1991
Electron affinities of the first‐row atoms revisited. Systematic basis sets and wave functions journal May 1992
Coupled cluster theory for high spin, open shell reference wave functions journal October 1993
Neural network potential energy surface for the low temperature ring polymer molecular dynamics of the H 2 CO + OH reaction journal March 2021
Molecular Transitions and Chemical Reaction Rates: The stochastic model relates the rate of a chemical reaction to the underlying transition probabilities journal June 1965
Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry journal May 2017
Is the Gas-phase OH+H 2 CO Reaction a Source of HCO in Interstellar Cold Dark Clouds? A Kinetic, Dynamic, and Modeling Study journal November 2017

Similar Records

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Chemistry