Neutron inelastic scattering studies of globular compounds
The use of neutron inelastic scattering measurements to determine the nature of the solid-state transitions in globular compounds is proposed and exemplified. Patterns were taken of the high- and low-temperature phases of solid cyclohexane, 2-2-dimethylbutane, and 1-4-diazo-bicyclo-(2.2.2)-octane. T...
Guardado en:
| Autor principal: | |
|---|---|
| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00219606_v38_n7_p1685_Becka |
| Aporte de: |
| id |
todo:paper_00219606_v38_n7_p1685_Becka |
|---|---|
| record_format |
dspace |
| spelling |
todo:paper_00219606_v38_n7_p1685_Becka2023-10-03T14:24:43Z Neutron inelastic scattering studies of globular compounds Becka, L.N. The use of neutron inelastic scattering measurements to determine the nature of the solid-state transitions in globular compounds is proposed and exemplified. Patterns were taken of the high- and low-temperature phases of solid cyclohexane, 2-2-dimethylbutane, and 1-4-diazo-bicyclo-(2.2.2)-octane. The first two have broad inelastic scattering peaks in the low-temperature phase. In the high-temperature phase these peaks disappear and the elastic peak broadens markedly. These changes are attributed to "quasi-free- rotation" of the molecules. Inelastic peaks do not appear in 1-4-diazo-bicyclo-(2.2.2)-octane, and the elastic peak does not broaden appreciably in the high-temperature phase. Self-diffusion coefficients D 3=4.5×10-5 cm2/sec for cyclohexane and D3=8.6×10-5 cm2/sec for 2-2-dimethylbutane were determined from the patterns of the liquids at 300°K using the "small motions" approximation. These values are larger than those obtained from NMR measurements, presumably as a result of irreversible rotation of the molecules. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00219606_v38_n7_p1685_Becka |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| description |
The use of neutron inelastic scattering measurements to determine the nature of the solid-state transitions in globular compounds is proposed and exemplified. Patterns were taken of the high- and low-temperature phases of solid cyclohexane, 2-2-dimethylbutane, and 1-4-diazo-bicyclo-(2.2.2)-octane. The first two have broad inelastic scattering peaks in the low-temperature phase. In the high-temperature phase these peaks disappear and the elastic peak broadens markedly. These changes are attributed to "quasi-free- rotation" of the molecules. Inelastic peaks do not appear in 1-4-diazo-bicyclo-(2.2.2)-octane, and the elastic peak does not broaden appreciably in the high-temperature phase. Self-diffusion coefficients D 3=4.5×10-5 cm2/sec for cyclohexane and D3=8.6×10-5 cm2/sec for 2-2-dimethylbutane were determined from the patterns of the liquids at 300°K using the "small motions" approximation. These values are larger than those obtained from NMR measurements, presumably as a result of irreversible rotation of the molecules. |
| format |
JOUR |
| author |
Becka, L.N. |
| spellingShingle |
Becka, L.N. Neutron inelastic scattering studies of globular compounds |
| author_facet |
Becka, L.N. |
| author_sort |
Becka, L.N. |
| title |
Neutron inelastic scattering studies of globular compounds |
| title_short |
Neutron inelastic scattering studies of globular compounds |
| title_full |
Neutron inelastic scattering studies of globular compounds |
| title_fullStr |
Neutron inelastic scattering studies of globular compounds |
| title_full_unstemmed |
Neutron inelastic scattering studies of globular compounds |
| title_sort |
neutron inelastic scattering studies of globular compounds |
| url |
http://hdl.handle.net/20.500.12110/paper_00219606_v38_n7_p1685_Becka |
| work_keys_str_mv |
AT beckaln neutroninelasticscatteringstudiesofglobularcompounds |
| _version_ |
1782027561647210496 |