Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 227-240).

Tesis (Doctor en ciencias químicas)--Madrid. / At head of title: Universidad Central. Facultad de Ciencias. Sección de Químicas. "Bibliografía": p. 82-85.

The design of catalysts for transition metal-mediated reactions is an active field in chemistry in the 21st century. It has been well recognised that ligands employed in these processes have a significant impact on the outcome of the reactions. The design and application of ligands in homogeneous catalysis reactions were the overarching aims of this project. Two areas were explored in this project, on the ligand synthesis side: 1. The use of directed ortho metallation (DoM) technology to synthesise unsymmetrical phosphines. 2. The synthesis of sterically hindered phosphines and their application to transition metal-mediated reactions. For the first sub-project, a range of N,N-dialkyl-diphenylphosphinic amides was synthesised in near quantitative yields. Deprotonation with s-BuLi and quenching the anion formed in the reaction with a range of electrophiles resulted in the desired ortho-substituted products in good yields. Differentiation of the second aromatic ring was possible, if the isolated mono-substituted products were used in further DoM reactions as starting materials. This methodology provided a range of highly substituted unsymmetrical phosphinic amides. Incorporation of other directing groups can change the selectivity of subsequent DoM reactions providing efficient routes to 2,2’ and 2,6-disubstituted products. Hydrolysis of the phosphinic amide moiety to the phosphinic acid with aqueous HCl, chlorination (SOCl2) and reaction of the acid chloride with a range of Grignard reagents provided an efficient method for the conversion of the phosphinic amide into a P-chirogenic but racemic phosphine oxide. Known methodology can convert this phosphine oxide into a phosphine that can be applied to transition metal catalysed reactions. This methodology provides an effective method for the synthesis of highly functionalised unsymmetrical phosphines. The approach facilitated substantial modifications to the ligand, which allows for efficient tailoring thereof for the metal-mediated reaction in which it is to be used. In the second sub-project, the DoM reaction was again employed but with (diaryl or dialkyl) phosphines as electrophilic quenches, resulting in the isolation of sterically hindered phosphines. Comparison between the ligands was made using the palladium-catalysed Suzuki reactions (catalytic approaches), Vaska type complexes (electronic effects) and phosphine selenium coupling constants (stereo-electronic effects). It was concluded that steric bulk and electronic characteristics affect the activity of catalysts formed from the ligands of this study, in line with the literature. The ligands were successfully applied to the palladium-catalysed Suzuki reaction using strongly deactivated aryl bromides and also some activated aryl chlorides as substrates at low (0.1% Pd) catalyst loadings. Significant improvements in catalytic activity were observed as the project progressed, using a structure-activity study as a guide. / Prof. D.B.G. Williams

Predicting the kinetics of a chemical reaction is a challenging task, particularly for systems in states far from equilibrium. This work discusses the use of a relatively new theory known as intrinsic quantum thermodynamics (IQT) and its mathematical framework steepest-entropy-ascent quantum thermodynamics (SEA-QT) to predict the reaction kinetics at atomistic levels of chemically reactive systems in the non-equilibrium realm. IQT has emerged over the last three decades as the theory that not only unifies two of the three theories of physical reality, namely, quantum mechanics (QM), and thermodynamics but as well provides a physical basis for both the entropy and entropy production. The SEA-QT framework is able to describe the evolution in state of a system undergoing a dissipative process based on the principle of steepest-entropy ascent or locally-maximal-entropy generation. The work presented in this dissertation demonstrates for the first time the use of the SEA-QT framework to model the evolution in state of a chemically reactive system as its state relaxes to stable equilibrium. This framework brings a number of benefits to the field of reaction kinetics. Among these is the ability to predict the unique non-equilibrium (kinetic) thermodynamic path which the state of the system follows in relaxing to stable equilibrium. As a consequence, the reaction rate kinetics at every instant of time is known as are the chemical affinities, the reaction coordinates, the direction of reaction, the activation energies, the entropy, the entropy production, etc. All is accomplished without any limiting assumption of stable or pseudo-stable equilibrium. The objective of this work is to implement the SEA-QT framework to describe the chemical reaction process as a dissipative one governed by the laws of quantum mechanics and thermodynamics and to extract thermodynamic properties for states that are far from equilibrium. The F+H2-->HF+H and H+F2-->HF+F reaction mechanisms are used as model problems to implement this framework. / Ph. D.

Large scale chemical reaction networks are a ubiquitous phenomenon, from the metabolism of living cells to processes in planetary atmospheres and chemical technology. At least some of these networks exhibit distinctive global features such as the “small world” behavior. The systematic study of such properties, however, suffers from substantial sampling biases in the few networks that are known in detail. A computational model for generating them is therefore required. Here we present a Toy Model that provides a consistent framework in which generic properties of extensive chemical reaction networks can be explored in detail and that at the same time preserves the “look-and-feel” of chemistry:  Molecules are represented as labeled graphs, i.e., by their structural formulas; their basic properties are derived by a caricature version of the Extended Hückel MO theory that operates directly on the graphs; chemical reaction mechanisms are implemented as graph rewriting rules acting on the structural formulas; reactivities and selectivities are modeled by a variant of the Frontier Molecular Orbital Theory based on the Extended Hückel scheme. The approach is illustrated for two types of reaction networks:  Diels−Alder reactions and the formose reaction implicated in prebiotic sugar synthesis.

The present apparatus was used to obtain rate data for the absorption of oxygen in a catalysed liquid phase reaction with acetaldehyde. The effects of several system parameters, namely, acetaldehyde concentration, catalyst concentration, partial pressure of oxygen and temperature on the rate of absorption were studied. An attempt was made to correlate absorption rates and product distribution with mathematical models based on the film theory and existing kinetic models proposed by Bolland and Bawn. Absorption rates predicted by these semi-empirical correlations are compared with experimental values. The differential equations involving diffusion with chemical reaction were solved on the digital computer IBM 7040 and the analog computer PACE TRlO. / Thesis / Master of Engineering (MEngr)

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Siu Chi-kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 48-52). / Abstracts in English and Chinese. / TITLE PAGE --- p.i / THESIS COMMITTEE --- p.ii / ABSTRACT (ENGLISH) --- p.iii / (CHINESE) --- p.iv / ACKNOWLEDGEMENTS --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / Chapter CHAPTER 1 --- Introduction --- p.1 / Chapter Section 1.1 --- Introduction --- p.1 / Chapter Section 1.2 --- Reaction of Chlorine Hydrolysis and Its Reverse Reaction --- p.2 / Chapter 1.2.1 --- Reaction in the Gas Phase --- p.2 / Chapter 1.2.2 --- Reaction in Aqueous Solution --- p.4 / Chapter 1.2.3 --- Reaction on Ice Surface --- p.5 / Chapter Section 1.3 --- Computational Method --- p.6 / Chapter Section 1.4 --- Study of Chemical Reaction by Constraint Molecular Dynamics --- p.8 / Chapter 1.4.1 --- Constraint Molecular Dynamics --- p.8 / Chapter 1.4.2 --- RATTLE Constraint Dynamics --- p.9 / Chapter 1.4.3 --- Free Energy of Chemical Reaction --- p.10 / Chapter 1.4.4 --- Radial Distribution Function --- p.11 / Chapter CHAPTER 2 --- "Ab initio Molecular Dynamics Study of the Reaction Between HC1 and HOC1 in Gas Phase, in Aqueous Solution and on Ice Surface" --- p.12 / Chapter Section 2.1 --- Structure of the Isolated Molecules --- p.13 / Chapter Section 2.2 --- Chlorine Hydrolysis in Aqueous Solution --- p.17 / Chapter 2.2.1 --- Model --- p.17 / Chapter 2.2.2 --- Results and Discussion --- p.18 / Chapter 2.2.3 --- Conclusion --- p.31 / Chapter Section 2.3 --- Heterogeneous Reaction of HC1 and HOC1 on Ice Surface --- p.32 / Chapter 2.3.1 --- Model --- p.32 / Chapter 2.3.2 --- Results and Discussion --- p.36 / Chapter 2.3.3 --- Conclusion --- p.45 / Chapter Section 2.4 --- "Comparison of the Reaction between HC1 and HOC1 in Gas Phase, in Aqueous Solution and on Ice Surface" --- p.46 / REFERENCES --- p.48

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