Solution NMR of Paramagnetic Molecules (eBook)

Front Cover 1
Solution NMR of Paramagnetic Molecules: Applications to Metallobiomolecules and Models 4
Copyright Page 5
Contents 8
Preface 6
Chapter 1. Introduction 12
1.1 Magnetic moments and magnetic fields 12
1.2 About the spin moments 15
1.3 Something more about the nuclear spin 19
1.4 A lot more about the electron spin 21
1.5 About the energies 26
1.6 Magnetization and magnetic susceptibility 26
1.7 The nuclear magnetic resonance experiment 30
1.8 General references 39
1.9 References 39
Chapter 2. The Hyperfine Shift 40
2.1 Nuclear hyperfine shift and relaxation 40
2.2 The magnetic nucleus–unpaired electron interaction: the hyperfine shift 43
2.3 Shift and spin patterns for protons and deuterons in solution 54
2.4 Proton hyperfine coupling and conformation 63
2.5 The origin of the shifts in heteronuclei 66
2.6 When is metal-centered pseudocontact shift expected? 70
2.7 Attempts to separate contact and pseudocontact shifts 72
2.8 The case of lanthanides and actinides 73
2.9 The pseudocontact shifts in paramagnetic metalloproteins 78
2.10 The effect of high magnetic fields 80
2.11 References 81
Chapter 3. Relaxation 86
3.1 Introduction 86
3.2 The correlation time 88
3.3 Electron relaxation 92
3.4 Nuclear relaxation due to dipolar coupling with unpaired electrons 100
3.5 Nuclear relaxation due to contact coupling with unpaired electrons 107
3.6 Curie nuclear spin relaxation 108
3.7 Further electronic effects on nuclear relaxation 112
3.8 A Comparison of dipolar, contact, and Curie nuclear spin relaxation 115
3.9 Nuclear parameters and relaxation 119
3.10 The effect of temperature on the electron–nucleus spin interaction 120
3.11 Stable free radicals 121
3.12 Nuclear relaxation parameters and structural information 122
3.13 Experimental accessibility of nuclear relaxation parameters 123
3.14 Redfield limit and beyond 125
3.15 References 127
Chapter 4. Chemical Exchange, Chemical Equilibria and Dynamics 130
4.1 Introduction 130
4.2 A pictorial view of chemical exchange 131
4.3 NMR parameters in the presence of exchange 133
4.4 Equilibrium constants 143
4.5 Beyond the concept of binding site 146
4.6 References 151
Chapter 5. Transition Metal Ions: Shift and Relaxation 154
5.1 Iron 154
5.2 Cobalt 179
5.3 Copper 185
5.4 Manganese 192
5.5 Chromium 196
5.6 Nickel 198
5.7 Other metal ions 200
5.8 References 209
Chapter 6. Magnetic Coupled Systems 216
6.1 The induced magnetic moment per metal ion in polymetallic systems, the hyperfine contact shift, and the nuclear relaxation rates 216
6.2 Electron relaxation and magnetic coupling 221
6.3 NMR of dimetallic systems 225
6.4 Beyond the Redfield limit: | J | /h > ts-1
6.5 Polymetallic systems 240
6.6 Superparamagnetism 249
6.7 References 250
Chapter 7. Nuclear Overhauser Effect 252
7.1 Introduction 252
7.2 Steady state NOE 254
7.3 Truncated NOE 266
7.4 Transient NOE 267
7.5 NOE in the rotating frame (ROE) 270
7.6 References 273
Chapter 8. Two-Dimensional Spectra and Beyond 274
8.1 Introduction 274
8.2 The EXSY experiment 276
8.3 The NOESY experiment 282
8.4 The ROESY experiment 290
8.5 The COSY experiment 293
8.6 The TOCSY experiment 298
8.7 Heterocorrelation spectroscopy 301
8.8 Coherence transfer caused by dipolar cross correlation 304
8.9 Beyond 2D spectroscopy 306
8.10 Tridimensional structures of paramagnetic proteins in solution 309
8.11 The effects of partial orientation 310
8.12 General references 311
8.13 References 311
Chapter 9. Hints on Experimental Techniques 314
9.1 How to record 1D NMR spectra of paramagnetic molecules 314
9.2 Measurements of T1 and T2 324
9.3 Measurements of NOE 325
9.4 2D spectra 330
9.5 Suggestions for spectral assignment 334
9.6 Nuclear magnetic relaxation dispersion (NMRD) 335
9.7 References 340
Appendices 342
Appendix I. NMR Properties of Nuclei 343
Appendix II. Dipolar Coupling Between Two Spins 347
Appendix III. Derivation of the Equations for Contact Shift and Relaxation in a Simple Case 349
Appendix IV. Derivation of the Pseudocontact Shift in the Case of Axial Symmetry 352
Appendix V. Relaxation by Dipolar Interaction Between Two Spins 355
Appendix VI. Calculation of (Sz): Curie's Law 361
Appendix VII. Derivation of the Equations Related to NOE 363
Appendix VIII. Magnetically Coupled Dimers in the High-Temperature Limit 367
Appendix IX. Product Operators: Basic Tools 370
Appendix X. Reference Tables 376
Subject Index 378