Contents ...
Contents vii
4.3 Intermolecular Dipole–Dipole Interactions 53
4.4 Electric Field Gradients
at Quadrupolar Nuclei 53
4.5 Nuclear Quadrupole Coupling Constant
as Measure of the Electric Field Gradient 54
4.6 Quadrupole Relaxation 56
Bibliography 57
5 Relaxation by Chemical Shift
Anisotropy, Spin–Rotation
Relaxation, Scalar Relaxation
of the Second Kind
and Cross-mechanisms 59
5.1 Relaxation by Chemical Shift Anisotropy 59
5.2 Spin–Rotation Relaxation 63
5.3 Interference Mechanisms of Nuclear Relaxation 64
5.4 Scalar Relaxation of the Second Kind 65
Bibliography 67
6 Nuclear Relaxation in Molecular
Systems with Anisotropic Motions 69
6.1 Spin–Lattice Nuclear Relaxation in Ellipsoidal
Molecules: Temperature Dependences
of T1 Times 70
6.2 How to Reveal Anisotropic Molecular Motions
in Solution 74
viii Contents
6.3 Nuclear Relaxation in the Presence
of Correlation Time Distributions 76
Bibliography 80
7 1H T1 Relaxation Diagnostics
in Solution 81
7.1 Revealing Weak Intermolecular Interactions
by T1 Time Measurements in Solution 82
7.2 T1 Studies of Exchange in Simple Molecular
Systems 87
7.3 Structural 1H T1 Criterion 89
7.4 Partially Relaxed NMR Spectra 92
Bibliography 94
8 Internuclear Distances from 1H T1
Relaxation Measurements
in Solution 97
8.1 X−H Distances: Metal–Hydride
Bond Lengths 98
8.1.1 How to Determine Metal–Hydride Bond Lengths
by Standard 1H T1 Measurements 101
8.1.2 Metal–Hydride Bond Lengths by 1H T1sel
and 1H T1min Measurements 104
8.2 Proton–Proton Distances by Standard
1H T1 Measurements 108
8.3 H−H Distances by T1sel/T1bis Measurements 111
8.4 H...H Distances in Intermediates 115