High-Resolution NMR Techniques in Organic Chemistry

by Claridge

• ISBN13: 9780080427980
• ISBN10: 0080427987
• Format: Hardcover
• Copyright: 1999-12-24
• Publisher: Pergamon Pr

Summary

Emphasis is on the more recently developed methods of solution-state NMR applicable to chemical research, which are chosen for their wide applicability and robustness. Softcover.

Table of Contents

Foreword	v
Preface	vii
Acknowledgements	ix
Introduction
The development of high-resolution NMR	1	(3)
Modern high-resolution NMR and this book	4	(4)
What this book contains	5	(2)
Pulse sequence nomenclature	7	(1)
Applying modern NMR techniques	8	(5)
References	12	(1)
Introducing high-resolution NMR
Nuclear spin and resonance	13	(3)
The vector model of NMR	16	(8)
The rotating frame of reference	16	(2)
Pulses	18	(2)
Chemical shifts and couplings	20	(1)
Spin-echoes	21	(3)
Time and frequency domains	24	(1)
Spin relaxation	25	(10)
Longitudinal relaxation: establishing equilibrium	26	(1)
Measuring T1 with the inversion-recovery sequence	27	(3)
Transverse relaxation: loss of magnetisation in the x--y plane	30	(1)
Measuring T2 with a spin-echo sequence	31	(4)
Mechanisms for relaxation	35	(10)
The path to relaxation	35	(2)
Dipole--dipole relaxation	37	(1)
Chemical shift anisotropy relaxation	38	(1)
Spin-rotation relaxation	39	(1)
Quadrupolar relaxation	40	(3)
References	43	(2)
Practical aspects of high-resolution NMR
An overview of the NMR spectrometer	45	(3)
Data acquisition and processing	48	(27)
Pulse excitation	48	(3)
Signal detection	51	(1)
Sampling the FID	52	(7)
Quadrature detection	59	(4)
Phase cycling	63	(2)
Dynamic range and signal averaging	65	(5)
Window functions	70	(3)
Phase correction	73	(2)
Preparing the sample	75	(6)
Selecting the solvent	75	(2)
Reference compounds	77	(1)
Tubes and sample volumes	78	(2)
Filtering and degassing	80	(1)
Preparing the spectrometer	81	(13)
The probe	82	(1)
Tuning the probe	83	(2)
The field-frequency lock	85	(2)
Optimising the field homogeneity: shimming	87	(7)
Spectrometer calibrations	94	(11)
Radiofrequency pulses	94	(5)
Pulsed field gradients	99	(5)
Sample temperature	104	(1)
Spectrometer performance tests	105	(6)
Lineshape and resolution	106	(1)
Sensitivity	107	(2)
Solvent presaturation	109	(1)
References	110	(1)
One-dimensional techniques
The single-pulse experiment	111	(5)
Optimising sensitivity	112	(2)
Quantitative measurements and integration	114	(2)
Spin decoupling methods	116	(9)
The basis of spin decoupling	117	(1)
Homonuclear decoupling	117	(3)
Heteronuclear decoupling	120	(5)
Spectrum editing with spin-echoes	125	(4)
The J-modulated spin-echo	125	(3)
APT	128	(1)
Sensitivity enhancement and spectrum editing	129	(14)
Polarisation transfer	130	(2)
INEPT	132	(7)
DEPT	139	(3)
PENDANT	142	(1)
Observing quadrupolar nuclei	143	(5)
References	145	(3)
Correlations through the chemical bond I: Homonuclear shift correlation
Introducing two-dimensional methods	148	(5)
Generating a second dimension	149	(4)
Correlation spectroscopy (COSY)	153	(7)
Correlating coupled spins	155	(1)
Interpreting COSY	156	(3)
Peak fine structure	159	(1)
Practical aspects of 2D NMR	160	(14)
2D lineshapes and quadrature detection	161	(6)
Axial peaks	167	(1)
Instrumental artefacts	168	(2)
2D data acquisition	170	(2)
2D data processing	172	(2)
Coherence and coherence transfer	174	(4)
Coherence-transfer pathways	177	(1)
Gradient-selected spectroscopy	178	(9)
Signal selection with pulsed field gradients	179	(4)
Phase-sensitive experiments	183	(1)
PFGs in high-resolution NMR	184	(2)
Practical implementation of PFGs	186	(1)
Alternative COSY sequences	187	(14)
Which COSY approach?	188	(1)
Double-quantum filtered COSY (DQF-COSY)	189	(8)
COSY-β	197	(2)
Delayed-COSY: detecting small couplings	199	(1)
Relayed-COSY	200	(1)
Total correlation spectroscopy (TOCSY)	201	(10)
The TOCSY sequence	202	(3)
Using TOCSY	205	(3)
Implementing TOCSY	208	(3)
Correlating dilute spins: INADEQUATE	211	(10)
2D INADEQUATE	212	(1)
1D INADEQUATE	213	(2)
Implementing INADEQUATE	215	(1)
Variations on INADEQUATE	216	(2)
References	218	(3)
Correlations through the chemical bond II: Heteronuclear shift correlation
Introduction	221	(1)
Sensitivity	222	(2)
Heteronuclear single-bond correlation spectroscopy	224	(20)
Heteronuclear multiple-quantum correlation (HMQC)	224	(5)
Heteronuclear single-quantum correlation (HSQC)	229	(1)
Practical implementations	230	(8)
Hybrid experiments	238	(6)
Heteronuclear multiple-bond correlation spectroscopy	244	(7)
The HMBC sequence	245	(3)
Applying HMBC	248	(3)
Traditional X-detected correlation spectroscopy	251	(8)
Single-bond correlations	252	(2)
Multiple-bond correlations and small couplings	254	(2)
References	256	(3)
Separating shifts and couplings: J-resolved spectroscopy
Introduction	259	(1)
Heteronuclear J-resolved spectroscopy	260	(7)
Measuring long-range proton-carbon coupling constants	263	(3)
Practical considerations	266	(1)
Homonuclear J-resolved spectroscopy	267	(6)
Tilting, projections and symmetrisation	268	(2)
Applications	270	(3)
Practical considerations	273	(1)
`Indirect' homonuclear J-resolved spectroscopy	273	(4)
References	274	(3)
Correlations through space: The nuclear Overhauser effect
Introduction	277	(2)
Definition of the NOE	279	(1)
Steady-state NOEs	279	(22)
NOEs in a two-spin system	279	(9)
NOEs in a multispin system	288	(6)
Summary	294	(2)
Applications	296	(5)
Transient NOEs	301	(3)
NOE kinetics	302	(1)
Measuring internuclear separations	303	(1)
Rotating-frame NOEs	304	(2)
Measuring steady-state NOEs: NOE difference	306	(7)
Optimising difference experiments	307	(6)
Measuring transient NOEs: Noesy	313	(15)
The 2D NOESY sequence	314	(6)
1D NOESY sequences	320	(3)
Applications	323	(3)
Measuring chemical exchange: Exsy	326	(2)
Measuring rotating-frame NOEs: Roesy	328	(7)
The 2D ROESY sequence	329	(3)
1D ROESY sequences	332	(1)
Applications	332	(3)
Measuring heteronuclear NOEs	335	(1)
Experimental considerations	336	(5)
References	337	(4)
Experimental methods
Composite pulses	341	(5)
A myriad of pulses	344	(1)
Inversion vs. refocusing	344	(2)
Broadband decoupling and spin-locks	346	(2)
Spin-locks	347	(1)
Adiabatic pulses	348	(1)
Selective excitation and shaped pulses	348	(11)
Shaped soft pulses	350	(4)
DANTE sequences	354	(1)
Excitation sculpting	355	(2)
Practical considerations	357	(2)
Solvent suppression	359	(7)
Presaturation	361	(1)
Zero excitation	362	(1)
Pulsed field gradients	363	(3)
Recent methods	366	(7)
Heterogeneous samples and MAS	366	(2)
Diffusion-ordered spectroscopy	368	(3)
References	371	(2)
Appendix. Glossary of acronyms	373	(2)
Index	375