EPR study of low molecular weight organogels by means of a nitroxide spin probe
| Autor: | Milan Jokić, Boris Rakvin, Janja Makarević, Mladen Andreis, Marina Kveder |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Nitroxide mediated radical polymerization
Spin–lattice relaxation Analytical chemistry EPR organogels nitroxide General Physics and Astronomy Nitroxyl Photochemistry Acceptor law.invention Physics::Fluid Dynamics Condensed Matter::Soft Condensed Matter Spin probe Condensed Matter::Materials Science Paramagnetism chemistry.chemical_compound chemistry law Molecule Physics::Chemical Physics Physical and Theoretical Chemistry Electron paramagnetic resonance |
| Zdroj: | Chemical Physics Letters. 420:443-447 |
| ISSN: | 0009-2614 |
| Popis: | It is shown that continuous wave electron paramagnetic resonance (EPR) spectroscopy combined with pulsed mode EPR exhibits improvement in studying the structural and dynamic characteristics of gels. This approach applied on bis(leucine) oxalyl diamide ethanol gels revealed that secondary structural units of self-organized gelator molecules promote the interactions with paramagnetic nitroxyl groups exhibiting hydrogen acceptor properties. Ethanol entrapped in the gel network was still prone to glass crystalline transformation. In the ethanol crystalline state, nitroxide spin lattice relaxation time revealed increased spin-phonon interactions as the gelator concentration was increased, while a complex behaviour was observed in ethanol glass. |
| Databáze: | OpenAIRE |
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