Guest Molecular Motion of [N(CH3)4][Cd3(CN)7] Benzene, Toluene, and Ethylbenzene Clathrates As Studied by 2H NMR
Autor: | Shin-ichi Nishikiori, Takafumi Kitazawa, Toschitake Iwamoto, Chong-Hyeak Kim |
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Rok vydání: | 2000 |
Předmět: | |
Zdroj: | The Journal of Physical Chemistry A. 104:2591-2598 |
ISSN: | 1520-5215 1089-5639 |
DOI: | 10.1021/jp9926286 |
Popis: | 2H NMR powder patterns of [N(CH3)4][Cd3(CN)7]·nG type benzene (n = 1.5, G = C6D6), toluene (n = 1, G = C6D5CD3 and C6D5CH3), and ethylbenzene (n = 1, G = C6D5CD2CD3, C6D6CH2CH3, and C6H5CD2CH3) clathrates have been measured between 128 and 468 K and analyzed in order to obtain information about motional behavior of the guest molecules before and during their thermal decomposition. (1) Benzene clathrate: below ca. 300 K the benzene molecule undergoes an ordinary in-plane rotational motion. Above 300 K, a sign of an out-of-plane motion like a precessional motion, which comes from the benzene escaping from the clathrate host owing to its thermal decomposition, was observed. (2) Toluene clathrate: below ca. 320 K the main motion is a 180° flip motion of the aromatic ring and its activation energy is estimated to be 33(1) kJ/mol. Above 320 K, in its thermal decomposition process, an in-plane two-site reorientational motion of the whole toluene molecule takes place. (3) Ethylbenzene clathrate: below ca. 350 ... |
Databáze: | OpenAIRE |
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