Elements of Molecular and Biomolecular Electrochemistry : An Electrochemical Approach to Electron Transfer Chemistry

by Savé; ant, Jean-Michel

• ISBN13: 9780471445739
• ISBN10: 0471445738
• Format: Hardcover
• Copyright: 2006-04-28
• Publisher: Wiley-Interscience

Summary

This book is based on the George Fisher Baker Lecture given by Jean-Michel Savéant at Cornell University in Fall 2002. * The first book focusing on molecular electrochemistry * Relates to other fields, including photochemistry and biochemistry * Outlines clearly the connection between concepts, experimental illustrations, proofs and supporting methods * Appendixes to provide rigorous demonstrations to prevent an overload of algebra in the main text * Applications-oriented, focused on analyzing the results obtained rather than the methodology

Author Biography

Jean-Michel Savéant is Professor at the Universite de Paris, and was selected as the 2002 Baker Lecturer at Cornell University.

Table of Contents

Preface	xiii
CHAPTER 1 Single Electron Transfer at an Electrode	1	(77)
1.1 Introduction	1	(1)
1.2 Cyclic Voltammetry of Fast Electron Transfers. Nernstian Waves	2	(8)
1.2.1 One-Electron Transfer to Molecules Attached to the Electrode Surface	2	(3)
1.2.2 One-Electron Transfer to Free-Moving Molecules	5	(5)
1.3 Technical Aspects	10	(18)
1.3.1 The Cyclic Voltammetry Experiment. Faradaic and Double-Layer Charging Currents. Ohmic Drop	10	(10)
1.3.2 Other Techniques. Convolution	20	(8)
1.4 Electron Transfer Kinetics	28	(34)
1.4.1 Introduction	28	(2)
1.4.2 Butler–Volmer Law and Marcus–Hush Model	30	(14)
1.4.3 Extraction of Electron Transfer Kinetics from Cyclic Voltammetric Signals. Comparison with Other Techniques	44	(13)
1.4.4 Experimental Testing of the Electron Transfer Models	57	(5)
1.5 Successive One-Electron Transfers vs. Two-Electron Transfers	62	(7)
1.5.1 Introduction	62	(2)
1.5.2 Cyclic Voltammetric Responses. Convolution	64	(5)
1.5.3 Response of Molecules Containing Identical and Independent Reducible or Oxidizable Groups	69	(6)
1.5.4 An Example of the Predominating Role of Solvation: The Oxidoreduction of Carotenoids	70	(3)
1.5.5 An Example of the Predominating Role of Structural Changes: The Reduction of trans-2,3-Dinitro-2-butene	73	(2)
References and Notes	75	(3)
CHAPTER 2 Coupling of Electrode Electron Transfers with Homogeneous Chemical Reactions	78	(104)
2.1 Introduction	78	(2)
2.2 Establishing the Mechanism and Measuring the Rate Constants for Homogeneous Reactions by Means of Cyclic Voltammetry and Potential Step Chronoamperometry	80	(45)
2.2.1 The EC Mechanism	80	(12)
2.2.2 The CE Mechanism	92	(2)
2.2.3 The Square Scheme Mechanism	94	(2)
2.2.4 The ECE and DISP Mechanisms	96	(6)
2.2.5 Electrodimerization	102	(4)
2.2.6 Homogeneous Catalytic Reaction Schemes	106	(13)
2.2.7 Electrodes as Catalysts	119	(2)
2.2.8 Numerical Computations. Simulations. Diagnostic Criteria. Working Curves	121	(4)
2.3 Application of Redox Catalysis to the Kinetic Characterization of Fast Follow-up Reactions	125	(7)
2.3.1 Principle and Achievements of the Method	125	(3)
2.3.2 Comparison with Fast Cyclic Voltammetry and Laser Flash Photolysis	128	(1)
2.3.3 Determination of the Standard Potential for the Formation of Very Unstable Primary Intermediates	129	(2)
2.3.4 Redox Catalysis of Electrocatalytic Processes	131	(1)
2.4 Product Distribution in Preparative Electrolysis	132	(8)
2.4.1 Introduction	132	(1)
2.4.2 General Features	133	(3)
2.4.3 Product Distribution Resulting from Competition Between Follow-up Reactions	136	(2)
2.4.4 The ECE–DISP Competition	138	(1)
2.4.5 Other Reactions Schemes	139	(1)
2.5 Chemical Classification and Examples of Coupled Reactions	140	(27)
2.5.1 Coupling of Single Electron Transfer with Acid–Base Reactions	140	(8)
2.5.2 Electrodimerization	148	(3)
2.5.3 Electropolymerization	151	(1)
2.5.4 Reduction of Carbon Dioxide	152	(2)
2.5.5 H-Atom Transfer vs. Electron + Proton Transfer	154	(4)
2.5.6 The SRN1 Substitution. Electrodes and Electrons as Catalysts	158	(5)
2.5.7 Conformational Changes, Isomerization, and Electron Transfer	163	(4)
2.6 Redox Properties of Transient Radicals	167	(11)
2.6.1 Direct Electrochemical Approach	167	(5)
2.6.2 Application of Laser Flash Electron Injection	172	(3)
2.6.3 Photomodulaltion Voltammetry	175	(2)
2.6.4 Application of Redox Catalysis	177	(1)
2.7 Electrochemistry as a Trigger for Radical Chemistry or Ionic Chemistry	178	(1)
References and Notes	179	(3)
CHAPTER 3 Electron Transfer, Bond Breaking, and Bond Formation	182	(69)
3.1 Introduction	182	(2)
3.2 Dissociative Electron Transfer	184	(10)
3.2.1 Thermodynamics. Microscopic Reversibility	184	(3)
3.2.2 The Morse Curve Model	187	(5)
3.2.3 Values of the Symmetry Factor and Variation with the Driving Force	192	(1)
3.2.4 Entropy of Activation	193	(1)
3.3 Interactions Between Fragments in the Product Cluster	194	(9)
3.3.1 Influence on the Dynamics of Dissociative Electron Transfers	195	(2)
3.3.2 Typical Example: Dissociative Electron Transfer to Carbon Tetrachloride	197	(2)
3.3.3 Stabilities of Ion-Radical Adducts as a Function of the Solvent	199	(1)
3.3.4 Dependency of In-Cage Ion–Radical Interactions on the Leaving Group	200	(3)
3.4 Stepwise vs. Concerted Mechanisms	203	(15)
3.4.1 Introduction	203	(1)
3.4.2 Diagnostic Criteria	204	(2)
3.4.3 How Molecular Structure Controls the Mechanism	206	(3)
3.4.4 Passage from One Mechanism to the Other upon Changing the Driving Force	209	(4)
3.4.5 Photoinduced vs. Thermal Processes	213	(3)
3.4.6 Does a Concerted Mechanism Mean That the Intermediate "Does Not Exist"?	216	(1)
3.4.7 π and σ Ion Radicals. Competition Between Reaction Pathways	216	(2)
3.5 Cleavage of Ion Radicals. Reaction of Radicals with Nucleophiles	218	(11)
3.5.1 Introduction	218	(1)
3.5.2 Heterolytic Cleavages. Coupling of Radicals with Nucleophiles	218	(7)
3.5.3 Homolytic Cleavages	225	(4)
3.6 Role of Solvent in Ion-Radical Cleavage and in Stepwise vs. Concerted Competitions	229	(10)
3.6.1 Introduction	229	(1)
3.6.2 Experimental Clues	230	(5)
3.6.3 A Simplified Model System	235	(4)
3.7 Dichotomy and Connections between SN2 Reactions and Dissociative Electron Transfers	239	(9)
3.7.1 Introduction	239	(1)
3.7.2 Experimental Approaches	240	(4)
3.7.3 Theoretical Aspects	244	(4)
References and Notes	248	(3)
CHAPTER 4 Molecular Catalysis of Electrochemical Reactions	251	(47)
4.1 Introduction	251	(1)
4.2 Homogeneous Molecular Catalysis	252	(16)
4.2.1 Contrasting Redox and Chemical Catalysis	252	(2)
4.2.2 The Reduction of Vicinal Dibromides. Outer- and Inner-Sphere Catalysts. Rates and Stereoselectivity	254	(6)
4.2.3 Homogeneous Chemical Catalysis of the Reduction of Carbon Dioxide. Synergistic Effect of Brönsted and Lewis Acids	260	(4)
4.2.4 Two-Step Chemical Catalysis of the Reduction of Alkyl Halides by Low-Valent Cobalamins and Cobinamides	264	(4)
4.3 Supported Molecular Catalysis (Immobilized Catalysts)	268	(28)
4.3.1 Redox and Chemical Catalysis at Monolayer and Multilayer Coated Electrodes	268	(2)
4.3.2 Catalysis at Monolayer Coated Electrodes	270	(9)
4.3.3 Permeation Through Electrode Coatings. Inhibition	279	(5)
4.3.4 Electron Hopping in Assemblies of Redox Centers	284	(3)
4.3.5 Catalysis at Multilayer Coated Electrodes	287	(5)
4.3.6 Combining an Electron-Shuttling Mediator with a Chemical Catalyst in a Multilayer Electrode Coating	292	(4)
References and Notes	296	(2)
CHAPTER 5 Enzymatic Catalysis of Electrochemical Reactions	298	(50)
5.1 Introduction	298	(1)
5.2 Homogeneous Enzymatic Catalysis	299	(16)
5.2.1 Introduction	299	(1)
5.2.2 The Ping-Pong Mechanism. Kinetic Control by Substrate and/or Cosubstrate	300	(6)
5.2.3 A Model Example: Glucose Oxidase with Excess Glucose	306	(1)
5.2.4 Molecular Recognition of an Enzyme by Artificial One-Electron Cosubstrates	307	(4)
5.2.5 Deciphering a Complex Electroenzymatic Response: Horseradish Peroxidase	311	(4)
5.3 Immobilized Enzymes in Monomolecular Layers	315	(25)
5.3.1 Introduction	315	(1)
5.3.2 The Ping-Pong Mechanism with an Immobilized Enzyme and the Cosubstrate in Solution	315	(8)
5.3.3 Antigen–Antibody Immobilization of Glucose Oxidase. Kinetic Analysis	323	(2)
5.3.4 Application to the Kinetic Characterization of Biomolecular Recognition	325	(7)
5.3.5 Immobilized Horseradish Peroxidase	332	(4)
5.3.6 Immobilization of Both the Enzyme and the Cosubstrate. Electron Transfer and Electron Transport in Integrated Systems	336	(4)
5.4 Spatially Ordered Multimonomolecular Layered Enzyme Coatings	340	(6)
5.4.1 Step-by-Step Antigen–Antibody Construction of Multimonomolecular Layer Enzyme Coatings	340	(2)
5.4.2 Reaction Dynamics with the Cosubstrate in Solution. Evidence for Spatial Order	342	(4)
References and Notes	346	(2)
CHAPTER 6 Appendixes	348	(122)
6.1 Single Electron Transfer at an Electrode	348	(25)
6.1.1 Laplace Transformation. Useful Definitions and Relationships	348	(1)
6.1.2 Cyclic Voltammetry of One-Electron Nernstian Systems. Current– and Charge–Potential Curves	348	(5)
6.1.3 Double-Layer Charging in Cyclic Voltammetry. Oscillating and Nonoscillating Behavior	353	(4)
6.1.4 Effect of Ohmic Drop and Double-Layer Charging on Nernstian Cyclic Voltammograms	357	(4)
6.1.5 Potential Step and Double Potential Step Chronoamperometry of Nernstian Systems	361	(1)
6.1.6 Overlapping of Double-Layer Charging and Faradaic Currents in Potential Step and Double Potential Step Chronoamperometry. Oscillating and Nonoscillating Behavior	361	(2)
6.1.7 Solvent Reorganization in Marcus–Hush Model	363	(5)
6.1.8 Effect of the Multiplicity of Electronic States in the Electrode	368	(3)
6.1.9 Cyclic Voltammetry of Two-Electron Nernstian Systems. Disproportionation	371	(2)
6.2 Coupling of Homogeneous Chemical Reactions with Electron Transfer	373	(65)
6.2.1 The EC Mechanism	373	(6)
6.2.2 The CE Mechanism	379	(3)
6.2.3 Double Potential Step Responses for Processes Involving First- or Second-Order Follow-up Reactions	382	(1)
6.2.4 The ECE and DISP Mechanisms	383	(8)
6.2.5 Electrodimerization	391	(7)
6.2.6 Competition Between Dimerization of and Electron Transfer to Intermediates	398	(5)
6.2.7 Homogeneous Catalysis	403	(11)
6.2.8 Product Distribution in Preparative Electrolysis	414	(24)
6.3 Electron Transfer, Bond Breaking, and Bond Formation	438	(3)
6.3.1 Contribution of the Cleaving Bond Stretching to Internal Reorganization of the First Step of the Stepwise Mechanism	438	(1)
6.3.2 Morse Curve Model of Intramolecular Dissociative Electron Transfer	439	(2)
6.4 Analysis of Supported Molecular Catalysis by Rotating Disk Electrode Voltammetry and Cyclic Voltammetry	441	(11)
6.4.1 Catalysis at Monolayer Electrode Coatings	441	(3)
6.4.2 Inhibition of Electron Transfer at Partially Blocked Electrodes	444	(1)
6.4.3 Equivalent Diffusion and Migration Laws for Electron Hopping Between Fixed Sites	445	(1)
6.4.4 Catalysis at Multilayered Electrode Coatings	446	(6)
6.5 Enzymatic Catalysis Responses	452	(17)
6.5.1 The Ping-Pong Mechanism in Homogeneous Enzymatic Catalysis	452	(5)
6.5.2 Catalysis and Inhibition in Homogeneous Systems	457	(5)
6.5.3 Catalysis at Multilayered Electrode Coatings	462	(7)
References and Notes	469	(1)
Glossary of Symbols	470	(11)
Index	481