An indirect method for the measurement of deuterium quadrupole coupling constants in liquids
An indirect method for the measurement of deuterium quadrupole coupling constants in liquids
复制标题
液体中氘四极耦合常数的间接测量方法
DOI：
10.1080/00268979809483239
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发表时间：
1998
影响因子：
1.7
通讯作者：
T. Farrar
中科院分区：
文献类型：
--
作者：
M. Wendt;T. Farrar
介绍了一种精确测量液体中四极耦合参数的新方法。实验和理论结果表明：对于甲醇中OD氘，氘四极耦合参数χD与氘化学位移δD的关系式为χD = 284 ~ 15.3δD；这种相关性的r2值为0.99。δD的直接测量为χD提供了准确的值，而χD又提供了分子相关时间的值。该方法应用于甲醇相关时间作为甲醇/CCl4系统浓度的函数的测量。分子相关时间以及溶液粘度的值提供了溶液中存在的甲醇簇的平均大小的估计。本文报道的数据表明，纯甲醇中甲醇团簇的平均体积约为230a3，介于环状五聚体（215a3）和环状五聚体（215a3）的体积之间。
A new method is described for the accurate measurement of quadrupole coupling parameters in liquids. Both experimental and theoretical data are given and show that for the OD deuteron in methanol the deuterium quadrupole coupling parameter χD is related to the deuterium chemical shift δD by the equation χD = 284—15.3δD; the R 2 value for this correlation is 0.99. The straightforward measurement of δD provides an accurate value for χD which in turn provides a value for the molecular correlation time. This methodology is applied to the measurement of the methanol correlation times as a function of concentration for the methanol/CCl4 system. The molecular correlation time along with a value for the solution viscosity provide an estimate of the average size for the methanol clusters present in the solution. The data reported here indicate that the average volume for the methanol clusters present in neat methanol is about 230 A3, a value about midway between the volume for a cyclic pentamer (215 A3) and a cycl...