Annual Reports on NMR Spectroscopy (eBook)

Front Cover 1
Annual Reports on NMR Spectroscopy 4
Copyright Page 5
Contents 6
Contributors 8
Preface 10
Chapter 1: 129Xe NMR Studies of Xenon Adsorption 12
1. Introduction 13
2. Basic Approaches of 129Xe NMR Spectroscopy 14
2.1. Chemical shift of adsorbed xenon 14
2.2. Variation of the 129Xe chemical shift due to porosity and temperature 16
2.3. Xenon exchange spectroscopy 19
2.4. NMR of adsorbed species as a probe for metal clusters in porous materials 20
3. Microporous Carbon Materials 21
3.1. Commercially available amorphous carbon materials 22
3.2. Pitch-based activated carbon modified by air oxidation/pyrolysis cycles 25
4. Mesoporous Carbon Materials 29
4.1. Testing the nanoparticles surface: Diamond and onion-like carbon aggregates 29
4.2. Filamentous carbon: Surface, porosity and paramagnetic impurities 31
4.3. Multi-wall carbon nanotubes 37
5. Conclusions 45
References 46
Chapter 2: NMR Studies for Mapping Structure and Dynamics of Nucleosides in Water 50
1. Introduction 51
2. Overview, Trends and Opinions 53
3. Nomenclature and Symbols 54
4. About Stacking of Nucleosides in Water 60
5. Structure in Water 61
5.1. Proton and carbon-13 data 80
5.2. Investigations by other nuclei 102
5.3. Quantum mechanical calculations 109
6. Dynamics in Water 114
6.1. Rotation barrier about the glycosidic bond 114
6.2. Sugar pseudo-rotation barrier 116
6.3. Rotation barrier about the exocyclic hydroxymethyl bond 117
6.4. Rotation barrier about the exocyclic amino bond 117
6.5. Chemical exchange with water 119
6.6. Relaxation time measurements 122
6.7. Diffusion experiments 131
6.8. Microdynamics in water: A tentative interpretation 136
7. Conclusion 139
Acknowledgements 139
References 140
Chapter 3: Time-Domain NMR Applied to Food Products 156
1. Introduction 158
2. History 160
3. Equipment 161
3.1. Magnets 161
3.2. Electronics 162
4. One-Dimensional Relaxometry and Diffusometry 163
4.1. Relaxometry 163
4.2. Diffusometry 164
5. Two-Dimensional NMR Relaxometry and Diffusometry 165
5.1. T1(.)–T2 correlations 165
5.2. T2–D correlations using pulsed-field gradients 166
5.3. T1–T2 and T2–D correlations in inhomogeneous fields 167
5.4. 2D exchange experiments 167
6. Data-Analysis Approaches 168
6.1. Signal processing 168
6.2. Model-driven analysis 168
6.3. Discrete relaxometric and diffusometric decays 172
6.4. Continuously distributed relaxometric and diffusometric decays 173
6.5. Multi-variate data analysis approaches 174
7. Benchtop Time-Domain NMR Applications 174
7.1. Solid fat content 174
7.2. Shelf-life stability of foods 176
7.3. Moisture and fat content 176
7.4. Microstructural features in food emulsions 177
7.5. Functionality of food ingredients 179
7.6. Functionality of heterogeneous food products 188
8. Mobile Time-Domain NMR Applications 196
8.1. Unilateral NMR sensors 196
8.2. Online quality inspection 196
9. Perspectives and Conclusions 197
9.1. Hardware 197
9.2. Fast measurements 197
9.3. In situ measurements 198
9.4. Enhancing information yield from the time-domain 198
Acknowledgement 198
References 198
Chapter 4: From Helical Jump to Chain Diffusion: Solid-State NMR Study of Chain Dynamics in Semi-Crystalline Polymers 210
1. Introduction 211
2. NMR Strategies for Probing Chain Dynamics in Solid Polymeric Materials 211
2.1. Spin–lattice relaxation measurement 212
2.2. Probing motionally modulated/averaged NMR interaction 212
2.3. Longitudinal spin exchange experiment 214
3. Helical Jump and Chain Diffusion in Semi-Crystalline Polymers 215
3.1. Helical jump in polymer crystals 216
3.2. Chain diffusion in semi-crystalline polymers and its influencing factors 219
3.3. The correlation between helical jump and chain diffusion 229
Acknowledgements 234
References 234
Subject Index 236
Color Plates 244