High-resolution solid-state NMR relaxometry as a kinetic tool for the study of ultrafast proton transfers in crystalline powders. Dimethyldibenzotetraaza[14]annulene
| Autor: | Hans-Heinrich Limbach, Bernd Wehrle, Christof-G. Hoelger, Hans Benedict |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Relaxometry
Magic angle Proton Chemistry Relaxation (NMR) General Engineering Spin–lattice relaxation Analytical chemistry Nanosecond Nuclear magnetic resonance Solid-state nuclear magnetic resonance Magic angle spinning Physics::Accelerator Physics Physical and Theoretical Chemistry Nuclear Experiment |
| Zdroj: | The Journal of Physical Chemistry. 98:843-851 |
| ISSN: | 1541-5740 0022-3654 |
| DOI: | 10.1021/j100054a020 |
| Popis: | NMR relaxometry combined with high-resolution solid-state NMR techniques has been explored as a kinetic tool for the study of ultrafast proton transfers in solids. Rate constants of proton transfer are obtained in the milli- to nanosecond time scale by analysis of the longitudinal spin-lattice relaxation times T 1 of heteronuclei located in such a way that their dipolar interaction to the mobile protons is modulated by the transfer process. The T 1 measurements are facilitated by proton cross-polarization (CP), magic angle spinning (MAS), and proton decoupling during the detection period. In contrast to the study of static powders, the CPMAS method also provides the equilibrium constants of proton transfer necessary to obtain the rate constants from the T 1 values |
| Databáze: | OpenAIRE |
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