NMR Study of Stable Radicals in the Gas Phase
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
Chemical Physics
ISSN: 0301-0104
|
| Вых. Данные |
Год: 1993,
Том: 172,
Номер: 2-3,
Страницы: 295-301
Страниц
: 7
DOI:
10.1016/0301-0104(93)80124-R
|
| Авторы |
Obynochny A.A.
1
,
Maryasov A.G.
2
,
Shakirov M.M.
1
,
Grigoriev I.A.
1
|
| Организации |
| 1 |
Institute of Chemical Kinetics and Combustion, Novoxbirsk 630090, Russian Federation
|
| 2 |
Institute of Catalysis, Novosibirsk 630090, Russian Federation
|
|
The temperature dependence of the NMR spectrum of methyl-substituted nitroxyl radical of the imidazoline series has been studied. The NMR signal induced by radicals in the gas phase has been observed. A shift of the lines of the NMR spectrum in the gas phase according to the Curie law is observed which allows one to determine the value of the hfi constant of the protons of different racial groups. The hfi constant for methyl-substituted radical within experimental accuracy coincides with those measured by other methods in the liquid phase. In the absorbed phase of the samples under study, a substantial contribution is made by the volumetric susceptibility of the liquid film. The diamagnetic contribution to the magnetic susceptibility of the radical in the liquid state has been measured (in the film of 2 × 10−6). When the thickness of the adsorbed film is small, the molecular exchange between the liquid and gas phases becomes noticeable, causing a corresponding additional shift of the lines. The gas-kinetic cross section for the radical (120 Å2) has been estimated from the temperature dependence of the line width in the gas phase.