Structure and Thermal Expansivity of Tetrahydrofuran Deuterate Determined by Neutron Powder Diffraction
Structure and Thermal Expansivity of Tetrahydrofuran Deuterate Determined by Neutron Powder Diffraction
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中子粉末衍射测定四氢呋喃氘酸盐的结构和热膨胀率
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Y. Ishii
中科院分区：
文献类型：
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作者：
Camille Y. Jones;S. Marshall;B. Chakoumakos;C. Rawn;Y. Ishii
四氢呋喃氘化物（一种笼形水合物）的晶体结构已经从7 - 265 K范围内五个温度下的中子粉末衍射数据中得到了改进。的热膨胀系数被证明是大于冰Ih在相同的温度范围内（T），在以前的研究中观察到的其他包合物。T的整体效应已被分解为结构中不同几何参数的贡献。因此，T的增加导致主体晶格框架的膨胀，同时增加D-D和O-O距离以及水分子的面外倾斜。对T的最大依赖性表现在D-D距离和六边形面的平面性畸变上，这在75 - 140 K范围内特别明显。笼的体积表现出复杂的依赖于T：从7到140 K，小笼的体积略有减少，大笼的体积增加，和140和205 K之间，趋势是相反的。最明显的结构…
The crystal structure of tetrahydrofuran deuterate, a clathrate hydrate, has been refined from neutron powder diffraction data at five temperatures in the range 7−265 K. The thermal expansivity was shown to be greater than that of ice Ih in the same range of temperature (T), as observed in previous studies of other clathrates. The overall effect of T has been resolved into contributions from different geometrical parameters in the structure. Thus, an increase in T results in expansion of the host-lattice framework with increases in both the D−D and O−O distances and out-of-plane tilting of water molecules. The greatest dependence on T is exhibited by the D−D distances and the distortion of the hexagonal faces from planarity, which is particularly pronounced in the range 75−140 K. The cage volumes show a complex dependence on T: from 7 to 140 K, the volume of the small cage decreases slightly and that of the large cage increases, and between 140 and 205 K, the trend is reversed. The most pronounced struct...