Electrode Dynamics provides an introduction to the field of electrode dynamics. The word electrochemistry commonly instils fear in students. This text aims to distil this fear with a gentle introduction to the kinetics of electron transfer reactions, and explores the potential applications of electrochemistry methodology. The early chapters provide a general introduction to the factors which control the rate of an electrode reaction. The later chapters deal with a variety of electrochemical applications including the study of surface processes, reaction mechanisms, electrosynthesis and the combination of electrochemistry with complementary techniques such as spectroscopy.
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Chapter
Reaction rates
This chapter defines the rate of a reaction and indicates how it is measured. Life is sustained by a network of reactions occurring at different rates. These rates are not fixed but respond to the needs of the cell or organism. The chapter explains that many reaction rates are found to be proportional to the concentrations of the reactants and in some cases the products. This recognition leads to the concepts of ‘rate law’, an expression for the rate in terms of the concentrations, and ‘rate constant’, a characteristic of the reaction. One aspect of discovering the rate law is to be able to classify reactions into different kinetic types, with the same type of reaction showing similar behaviour. To conclude, the chapter presents a case study on measuring the kinetics of protein folding.
Book
M. Brouard
Reaction Dynamics provides a concise account of the dynamics and kinetics of elementary reactions in the gas phase, and is structured to emphasize the relationship between thermal rate coefficients and the microscopic mechanisms of chemical reactions. The theoretical framework necessary to predict the dynamics and kinetics of elementary reactions is introduced and illustrated by reference to numerous theoretical and experimental studies.
Book
Carol E. Wayne and Richard P. Wayne
Photochemistry studies this subject which sits in the broad filed of chemistry. The text describes the 'new' chemistry that follows the absorption of light, and explains how light has this extraordinary influence on chemical behaviour. Examples of established principles are presented examining the way in which life and the other natural processes depend on photochemistry, and also how photochemistry can be used in a variety of applications. Chapters focus on chemical change, photophysics, photochemical kinetics, photochemistry in nature, and applied photochemistry.
Chapter
Energetics, kinetics, and mechanism
This chapter reviews some basic aspects of the energetics and kinetics of radical processes and the factors that determine them. It examines the decomposition of a dilute solution of a diacyl peroxide in an unreactive, non-polar medium, such as benzene. It also provides a kinetic analysis of the use of peroxide to initiate a chain reaction in which an alkene is polymerized, and demonstrates how slow propagations may compete with diffusion-controlled termination. The chapter discusses the modest stabilization found with alkyl-substituted methyl radicals that can be attributed in part to hyperconjugation, which is revealed both by theory and by spectroscopic data. The chapter finally explains that stabilization is a thermodynamic property that arise from electron delocalization.
Book
John Perkins
Radical Chemistry begins by defining the term radical. It is exactly 100 years since Moses Gomberg claimed that he had observed a substance containing a trivalent carbon atom i.e. a carbon-centred 'free radical' (nowadays, simply a carbon-centred 'radical'). The subsequent development of radical chemistry was at first very slow, but blossomed with the development of synthetic polymers, especially during and after World War II. In what is now generally understood by radical chemistry we are dealing with reactive, short-lived species which are electrically neutral. By the late 1960s, the essential features of the subject were well understood, and quantitative data on the energetics and kinetics of reactive radicals were rapidly accumulating. This text sets out to present that basic understanding in a modern context, in which extensive use of radical reactions is now being made in organic synthesis, and where, in the life sciences, reactive radicals are being recognizsed both as mediators of many disease conditions, and frequently as key players in mechanisms of enzyme action.
Book
Nathan Lawrence, Jay Wadhawan, and Richard Compton
Foundations of Physical Chemistry presents a grounding in the field of physical chemistry. The early chapters cover the structure of atoms, ions and molecules, reactivity, kinetics, and equilibria. The final chapter gives an insight into more advanced areas, drawing on real-world examples.
Book
Modern Liquid Phase Kinetics aims to show that the world is not at equilibrium, and the events that give vitality and movement are transitions towards equilibrium from the present state of imbalance. Chemical transformations often contribute fundamentally to this process and their study is challenging and important. The early chapters of this text provide a basic introduction to the kinetics of simple and complex reaction systems in solution. The remaining chapters present a treatment of the more advanced topics, comprising solvent effects, fast reaction techniques, and heterogeneous liquid—liquid two-phase systems. The last introduces currently active and important research areas in solution kinetics, including phase-transfer catalysis, and diffusion and transport in chemical and biological membranes.
Book
Stephen J. Jenkins
Foundations of Surface Science provides a broad coverage of this topic. The chapters are arranged thematically, covering thermodynamics; symmetry and structure; electronic structure; and the kinetics and dynamics of surfaces, respectively. The text contains a final chapter which covers key experimental techniques, including some suited to ambient or wet conditions, providing a unified overview both of classic methods and of recent advancements in the field. The text also includes an extended discussion of the growing role played by first-principles density functional theory in contemporary surface science research, as an integral part of the techniques chapter.
Chapter
Kinetics and Dynamics
This chapter explores the fundamental processes that occur at surfaces—adsorption, desorption, vibration, and reaction—understanding them as ongoing events taking place during the passage of time, as opposed to historical facts to be explained after time has elapsed. In so doing, it addresses both kinetics (variation of macroscopic system properties) and dynamics (microscopic motion of atoms and molecules) to present a 'moving picture' of the surface as a place of constant agitation and continual change. A full description of adsorption dynamics should be multidimensional, but one- and two-dimensional approximations may yet provide useful insights if treated with caution. Meanwhile, the kinetic order of desorption may be established by analysis of peaks obtained in a temperature-programmed desorption (TPD) experiment. The chapter also considers the Brønsted–Evans–Polanyi relation and looks at how quantised surface-localised vibrations (surface phonons) of various types may be observed at frequencies disallowed in the bulk.
Chapter
Introduction
This introductory chapter provides an overview of solid surfaces, which are of particular importance in everyday life. Some of the most important areas in which they play a vital role include heterogeneous catalysis and corrosion. The behaviour of surfaces is also crucial in the fields of electrochemistry, photography, colloids, optics, data storage, and, increasingly, in biological applications such as the use of membranes and biosensors. Thus, the study of surfaces and their behaviour requires a wide range of chemical knowledge and understanding. This books assumes a knowledge of the basic principles of physical chemistry, especially kinetics, dynamics, and thermodynamics. The chapter then looks at the single crystal surface, before outlining the techniques for studying surfaces.
Chapter
Nucleation
This chapter discusses nucleation, which is central to all types of crystallization. Nucleation is the process of creating a new solid phase from a supersaturated homogenous mother phase. The chapter derives a kinetic expression for the rate of nucleation and then extends the concepts involved to show simultaneous nucleation of two phases in a polymorphic system and nucleation in constrained volumes. It also considers heterogeneous systems in which nucleation can be catalysed by the presence of an existing surface in the form of ill-defined ‘dust’, seeds of the crystallizing material (secondary nucleation), or pre-ordered molecular species such as monolayers or micelles. Finally, the chapter looks at the techniques for detecting nucleation events.
Chapter
Protein folding and design
This chapter describes the mechanism of protein folding. The relationship between amino acid sequence and protein structure, demonstrated by spontaneous folding and reversible denaturation, establishes a logical connection between the one-dimensional world of genetic information in DNA and the three-dimensional world of biological structure. The study of the process of protein folding addresses the question of how a polypeptide sequence gets from the denatured to the native state. The chapter then discusses the basic principles of thermodynamics and kinetics, and their application to protein folding. It also examines chevron plots, looking at the effect of denaturants on rates of folding and unfolding. Moreover, the chapter considers the relationships among several general concepts that have emerged from investigations of protein folding. These include the molten globule and the folding funnel. Finally, the chapter studies the GroEL–GroES system, as well as protein engineering.
Chapter
Kinetics: what affects the speed of a reaction?
This chapter discusses chemical kinetics, looking at the factors that control the rate of a chemical reaction. The rate of a chemical reaction is the speed of change in concentration of reactants or products per unit time as the reaction proceeds. One can determine the rate of a reaction by measuring the concentrations of reactants or products at different times during the course of a reaction, and plotting on a graph the change of concentration with time. Every reaction has an energy threshold called the activation energy that must be reached before the reaction can occur. The chapter then considers catalysis and enzymes, and their impact upon the activation energy and reaction kinetics, before explaining enzyme kinetics and enzyme inhibition and the ways in which these can be described.
Book
Elaine M. McCash
Surface Chemistry conveys the fundamental concepts of surface chemistry. It describes solid surfaces, their properties at macroscopic and microscopic levels and their interrelation, and reflects the striking advances made in recent years through the study of well-defined single crystal surfaces. It begins with a discussion of the clean surface, its electronic and structural properties and goes on to describe adsorption, desorption, reactions, and reactivity at the surface. In the final section, the growth and properties of ultrathin films is introduced. Starting with the established concepts in terms of kinetics and thermodynamics, the book develops to look at phenomena such as surface dynamics and photochemistry. Important techniques which are applied to surfaces are also covered; this is a concept-driven rather than technique-driven approach.
Chapter
Reaction mechanisms
This chapter describes reaction mechanisms. Many reactions occur in a series of steps
called elementary reactions, each of which involves only one or two molecules or ions. The
molecularity of an elementary reaction is the number of molecules coming together to react.
The chapter then looks at the formulation of rate laws. In a pre-equilibrium, it is assumed
that an intermediate establishes a rapid equilibrium with the reactants and the subsequent
formation of products is slow. In the steady-state approximation, it is assumed that the
concentrations of all reaction intermediates remain constant and small throughout the
reaction. The chapter also considers the rate-determining step, which is the slowest step in
a reaction mechanism that controls the rate of the overall reaction. Provided a reaction has
not reached equilibrium, the products of competing reactions are controlled by kinetics.
Finally, the chapter discusses the Lindemann mechanism of ‘unimolecular’ reactions.
Book
Arthur M. Lesk
Introduction to Protein Science firstly outlines the topics ahead. The first main topic is protein structure and protein structure determination. The next subject the text considers is bioinformatics of protein sequence and structure. Proteins as catalysts is examined after that. This discussion particularly looks at enzyme structure, kinetics, and mechanisms. The text then moves on to describe proteins with partners, the evolution of protein structure and function, and protein folding and design. Finally, it looks at proteomics and systems biology.
Chapter
Photochemical kinetics
This chapter evaluates photochemical kinetics. It shows how an analysis of information about the rates of reactions can lead to a better and more quantitative understanding of photochemical processes. Reaction kinetics is the part of chemistry that deals with reaction rates, and photochemical kinetics affords valuable insights into the mechanisms of photochemical reactions and even into the detailed nature of individual elementary reactionary steps. The kinetic approach is also a valuable adjunct to studies of absorption spectra, fluorescence, and many other optical and photochemical phenomena. Its use has been implicit in much of the discussion of previous chapters, and this chapter also provides a more specific account of the relation between kinetics and photochemistry.
Chapter
Calculations in the molecular biosciences
This chapter addresses the analysis of some important types of biological processes. It begins by looking at the energetics of processes. In biological systems we deal with two main types of processes, namely chemical reactions in which covalent bonds are broken and made, so that one or more new compounds are made from the starting compounds, and complex formation in which two (or more) compounds can associate reversibly with one another. The science of thermodynamics is concerned with the overall changes in energy when processes occur; it can be used to predict how far a process will proceed, i.e. does the equilibrium lie more towards the side of the products or the reactants? The chapter then discusses binding equilibria; this includes the kinetics of enzyme-catalysed reactions since many of the equations involved are similar. The chapter also considers radioactivity, which is widely used to track specific compounds.
Chapter
Kinetics and drug stability
Gary Moss
This chapter examines the significance of kinetics and drug stability. Kinetic studies can provide information on the mechanism of reactions, and allow the degree of change during a process to be measured against time. Moreover, kinetics is a field that applies to the process of drug absorption, distribution, and elimination by the body. The chapter looks at reaction rates and reaction orders before considering the factors affecting the rate of reaction of dosage forms. The Arrhenius equation may be used to model the relationship between rate constants and temperature, which allows for the estimation of the expected shelf life of a drug at its normal storage temperature.
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