Deuteron NMR studies of guest motion in alkanoic acid urea inclusion compounds
Deuteron NMR studies of guest motion in alkanoic acid urea inclusion compounds
复制标题
链烷酸脲包合物中客体运动的氘核核磁共振研究
DOI：
10.1063/1.476149
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发表时间：
1998
影响因子：
4.4
通讯作者：
R. Subramanian
中科院分区：
文献类型：
--
作者：
R. Vold;G. Hoatson;R. Subramanian
在-30 ° C至+45 °C温度范围内，测量了含烷基氘代辛酸-d18、十二烷酸-d23和十六烷酸-d31的多晶脲包合物的塞曼（T1 Z）和四极（T1 Q）级氘弛豫时间的取向依赖性。这些数据被拟合到一个模型，根据Redfield弛豫理论，其中包括快速旋转的长分子轴和较慢的，有限的角度振动的个别CD债券的垂直轴。辛酸-d18、十二烷酸-d23和十六烷酸-d31客体绕长轴旋转扩散的活化能分别为17.4± 0.8kJ/mol、14.4± 0.6kJ/mol和22.5± 0.4kJ/mol。这些值大于具有相同碳原子数的烷烃客人，并且它们随着链长的增加而增加得更快。四极耦合常数，测定在室温下从测量大单晶，是一致的一个小的gauche…
The orientation dependence of deuteron relaxation times of Zeeman (T1Z) and quadrupole (T1Q) order have been measured in the temperature range −30 to +45 °C for polycrystalline urea inclusion compounds containing alkyl deuterated octanoic acid-d18, dodecanoic acid-d23, and hexadecanoic acid-d31. These data were fitted to a model, based on Redfield relaxation theory, which incorporates rapid rotation about the long molecular axis and slower, limited angle libration of individual CD bonds about a perpendicular axis. The activation energies for rotational diffusion about the long axis are 17.4±0.8 kJ/mol for octanoic acid-d18, 14.4±0.6 kJ/mol for dodecanoic acid-d23, and 22.5±0.4 kJ/mol for hexadecanoic acid-d31 guests. These values are larger than those for alkane guests with the same number of carbon atoms, and they increase more rapidly with increasing chain length. Quadrupole coupling constants, determined at room temperature from measurements on large single crystals, are consistent with a small gauche ...
N-乙酰甘氨酸中的氘四极耦合和固体聚（γ-苄基-L-谷氨酸）中的解放动力学。
影响因子：
2.9
作者：
Usha,MG;Peticolas,WL;Wittebort,RJ
通讯作者：
Wittebort,RJ