Cross-polarization dynamics and spin diffusion in some aromatic compounds
| Autor: | Muriel Hervé, Jérôme Hirschinger |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Nuclear and High Energy Physics
Radiation Indoles Magnetic Resonance Spectroscopy Proton Chemistry Metallocenes Intermolecular force Analytical chemistry General Chemistry Diffusion Chemical physics Intramolecular force Proton spin crisis Phenomenological model Spin diffusion Magic angle spinning Organometallic Compounds Ferrous Compounds Diffusion (business) Instrumentation |
| Zdroj: | Solid state nuclear magnetic resonance. 3(3) |
| ISSN: | 0926-2040 |
| Popis: | The inversion-recovery cross-polarization (IRCP) magic-angle spinning experiment has been applied to study the 13C1H cross-polarization dynamics of protonated aromatic carbons in ferrocene, 5,6-dimethoxyindole (DMI) and some indole derivatives. Using the 13C-detected proton spin diffusion (SD) experiment recently developed by Zhang et al. [Solid State Nucl. Magn. Reson., 1 (1992) 313], the slow decaying or incoherent stage of the IRCP experiment is shown to be controlled by the spin diffusion process at the directly bound proton. Moreover, a simple phenomenological model treating spin diffusion as a relaxation process provides an excellent agreement with both the IRCP and SD experimental data for all the different CH pairs of DMI and its derivatives. The resulting time constants of the non-exponential spin diffusion decays are related to the local intra- and intermolecular network of dipolar interactions. This model is nevertheless found to be inadequate for ferrocene because intramolecular spin diffusion then has an inhomogeneous character. |
| Databáze: | OpenAIRE |
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