Slow-Motion Theory of Nuclear Spin Relaxation in Paramagnetic Low-Symmetry Complexes: A Generalization to High Electron Spin

✍ Scribed by T Nilsson; J Kowalewski

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 152 KB
• Volume: 146
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.2000.2125

✦ Synopsis

The slow-motion theory of nuclear spin relaxation in paramagnetic low-symmetry complexes is generalized to comprise arbitrary values of S. We describe the effects of rhombic symmetry in the static zero-field splitting (ZFS) and allow the principal axis system of the static ZFS tensor to deviate from the molecule-fixed frame of the nuclear-electron dipole-dipole tensor. We show nuclear magnetic relaxation dispersion (NMRD) profiles for different illustrative cases, ranging from within the Redfield limit into the slow-motion regime with respect to the electron spin dynamics. We focus on S ‫؍‬ 3/2 and compare the effects of symmetrybreaking properties on the paramagnetic relaxation enhancement (PRE) in this case with that of S ‫؍‬ 1, which we have treated in a previous paper. We also discuss cases of S ‫؍‬ 2, 5/2, 3, and 7/2. One of the main objectives of this investigation, together with the previous papers, is to provide a set of standard calculations using the general slow-motion theory, against which simplified models may be tested.