Molecular dynamics in solid l-adrenaline by proton NMR
| Autor: | E.R Andrew, B. Peplinska, Marek Kempka |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Nuclear and High Energy Physics
Radiation Epinephrine Relaxation (NMR) Temperature General Chemistry Activation energy Molecular dynamics chemistry.chemical_compound chemistry Computational chemistry Side chain Proton NMR Thermodynamics Physical chemistry Protons Ethylamine Methylene Nuclear Magnetic Resonance Biomolecular Instrumentation Methyl group |
| Zdroj: | Solid State Nuclear Magnetic Resonance. 10:117-121 |
| ISSN: | 0926-2040 |
| Popis: | Proton NMR measurements of the spectrum, second moment, spin-lattice relaxation time T 1 and dipolar relaxation time T 1D were carried out on polycrystalline l -adrenaline at 14 and 25 MHz between 55 and 400 K. Between 70 K and 250 K relaxation is dominated by C 3 reorientation of the single methyl group in each molecule, characterized by an activation energy 8.3±0.3 kJ/mole. Below 70 K tunnelling assisted relaxation is significant, characterized by an excitation energy of 1.9±0.2 kJ/mole. Above 250 K an additional molecular motion becomes significant, with activation energy above 28 kJ/mole, attributed to conformational motion of the methylene group in the ethylamine side chain. |
| Databáze: | OpenAIRE |
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