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Rate Constant Calculation for Thermal Reactions: Methods and Applications



Rate Constant Calculation for Thermal Reactions: Methods and Applications

Herbert DaCosta (Editor), Maohong Fan (Editor)

ISBN: 978-1-118-16611-6 December 2011 360 Pages


Providing an overview of the latest computational approaches to estimate rate constants for thermal reactions, this book addresses the theories behind various first-principle and approximation methods that have emerged in the last twenty years with validation examples. It presents in-depth applications of those theories to a wide range of basic and applied research areas. When doing modeling and simulation of chemical reactions (as in many other cases), one often has to compromise between higher-accuracy/higher-precision approaches (which are usually time-consuming) and approximate/lower-precision approaches (which often has the advantage of speed in providing results). This book covers both approaches. It is augmented by a wide-range of applications of the above methods to fuel combustion, unimolecular and bimolecular reactions, isomerization, polymerization, and to emission control of nitrogen oxides. An excellent resource for academics and industry members in physical chemistry, chemical engineering, and related fields.
Herbert DaCosta and Maohong Fan



1. Overview of Thermochemistry and Its Application to Reaction Kinetics 3
Elke Goos and Alexander Burcat

1.1. History of Thermochemistry 3

1.2. Thermochemical Properties 5

1.3. Consequences of Thermodynamic Laws to Chemical Kinetics 8

1.4. How to Get Thermochemical Values? 10

1.5. Accuracy of Thermochemical Values 16

1.6. Representation of Thermochemical Data for Use in Engineering Applications 21

1.7. Thermochemical Databases 26

1.8. Conclusion 27

2. Calculation of Kinetic Data Using Computational Methods 33
Fernando P. Cossío

2.1. Introduction 33

2.2. Stationary Points and Potential Energy Hypersurfaces 34

2.3. Calculation of Reaction and Activation Energies: Levels of Theory and Solvent Effects 38

2.4. Estimate of Relative Free Energies: Standard States 47

2.5. Theoretical Approximate Kinetic Constants and Treatment of Data 50

2.6. Selected Examples 51

2.7. Conclusions and Outlook 61

3. Quantum Instanton Evaluation of the Kinetic Isotope Effects and of the Temperature Dependence of the Rate Constant 67
Jiøí Vanícek

3.1. Introduction 67

3.2. Arrhenius Equation, Transition State Theory, and the Wigner Tunneling Correction 68

3.3. Quantum Instanton Approximation for the Rate Constant 69

3.4. Kinetic Isotope Effects 71

3.5. Temperature Dependence of the Rate Constant 73

3.6. Path Integral Representation of Relevant Quantities 75

3.7. Examples 81

3.8. Summary 88

4. Activation Energies in Computational Chemistry—A Case Study 93
Michael Busch, Elisabet Ahlberg and Itai Panas

4.1. Introduction 93

4.2. Context and Theoretical Background 95

4.3. Computational Details 99

4.4. Recent Advances and New Results 99

4.5. Concluding Remarks 107

5. No Barrier Theory—A New Approach to Calculating Rate Constants in Solution 113
J. Peter Guthrie

5.1. Introduction 113

5.2. The Idea Behind No Barrier Theory 114

5.3. How to Define the Surface and Find the Transition State 118

5.4. What is Needed for a Calculation? 124

5.5. Applications to Date 125

5.6. Future Prospects for NBT 140


6. Quantum Chemical and Rate Constant Calculations of Thermal Isomerizations, Decompositions, and Ring Expansions of Organic Ring Compounds, Its Significance to Cohbusion Kinetics 149
Faina Dubnikova and Assa Lifshitz

6.1. Prologue 149

6.2. Small Organic Ring Compounds 152

6.3. Pyrrole and Indole 156

6.4. Dihydrofurans and Dihydrobenzofurans 160

6.5. Naphthyl Acetylene–Naphthyl Ethylene 166

6.6. Ring Expansion Processes 168

6.7. Benzoxazole–Benzisoxazoles 173

6.8. Conclusion 181

7. Challenges in the Computation of Rate Constants for Lignin Model Compounds 191
Ariana Beste and A.C. Buchanan, III

7.1. Lignin: A Renewable Source of Fuels and Chemicals 191

7.2. Mechanistic Study of Lignin Model Compounds 196

7.3. Computational Investigation of the Pyrolysis of β-O-4 Model Compounds 201

7.4. Case Studies: Substituent Effects on Reactions of Phenethyl Phenyl Ethers 214

7.5. Conclusions and Outlook 232

8. Quantum Chemistry Study on the Pyrolysis Mechanisms of Coal-Related Model Compounds 239
Baojun Wang, Riguang Zhang and Lixia Ling

8.1. Introduction to the Application of Quantum Chemistry Calculation to Investigation on Models of Coal Structure 239

8.2. The Model for Coal Structure and Calculation Methods 240

8.3. The Pyrolysis Mechanisms of Coal-Related Model Compounds 243

8.4. Conclusion 276

9. Ab Initio Kinetic Modeling of Free-Radical Polymerization 283
Michelle L. Coote

9.1. Introduction 283

9.2. Ab Initio Kinetic Modeling 287

9.3. Quantum Chemical Methodology 291

9.4. Case Study: RAFT Polymerization 296

9.5. Outlook 300

10. Intermolecular Electron Transfer Reactivity for Organic Compounds Studied Using Marcus Cross-Rate Theory 305
Stephen F. Nelsen and Jack R. Pladziewicz

10.1. Introduction 305

10.2. Determination of ∆Gii (fit) Values 307

10.3. Why is the Success of Cross-Rate Theory Surprising? 309

10.4. Major Factors Determining Intrinsic Reactivities of Hydrazine Couples 310

10.5. Nonhydrazine Couples 315

10.6. Comparison of D∆Gii (fit) with D∆Gii (self) Values 318

10.7. Estimation of Hab from Experimental Exchange Rate Constants and DFT-Computed l 320

10.8. Comparison with Gas-Phase Reactions 333

10.9. Conclusions 333

References 334