Inertial and attractive potential effects on rotation of solitary water molecules in apolar and polar solvents
Inertial and attractive potential effects on rotation of solitary water molecules in apolar and polar solvents
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惯性和吸引势对非极性和极性溶剂中孤立水分子旋转的影响
DOI：
10.1063/1.463910
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发表时间：
1992
影响因子：
4.4
通讯作者：
Chihiro Wakai
中科院分区：
文献类型：
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作者：
M. Nakahara;Chihiro Wakai
在很宽的温度范围内，在很低浓度（8-70 mM）的一系列溶剂中测量了孤水分子（D2O）的氘核磁共振自旋晶格弛豫时间T1；研究溶剂为四氯化碳（10 ~ 40℃）、苯（10 ~ 60℃）、氯仿（- 40 ~ 50℃）、乙腈（- 40 ~ 50℃）、丙酮（- 40 ~ 50℃）。30℃时，CCl4、C6H6、CHCl3、CH3CN和（CH3）2CO中具有极小惯性矩(I)的D2O的取向相关时间τ2R分别为96、224、230、625和826 fs，远小于体积值（2210 fs）。τ2R值与水在每种溶剂中的质子化学位移成正比，在短范围内作为溶质-溶剂相互作用强度的量度。另一方面，τ2R与溶剂粘度几乎成反比，这与简单的流体动力摩擦模型不一致。相关时间（τ*）由自由旋转体相关标度…
Deuteron nuclear magnetic resonance spin–lattice relaxation times T1 have been measured for solitary water molecules (D2O) at very low concentrations (8–70 mM) in a series of solvents over a wide range of temperatures; the solvents studied are carbon tetrachloride (10 to 40 °C), benzene (10 to 60 °C), chloroform (−40 to 50 °C), acetonitrile (−40 to 50 °C), and acetone (−40 to 50 °C). The orientational correlation times τ2R for D2O with extremely small moments of inertia (I) in CCl4, C6H6, CHCl3, CH3CN, and (CH3)2CO at 30 °C are, respectively, 96, 224, 230, 625, and 826 fs, which are all by far smaller than the bulk value (2210 fs). The τ2R value is proportional to the proton chemical shift of water in each solvent which is taken as a measure of the strength of solute–solvent interactions in the short range. On the other hand, τ2R is almost inversely proportional to solvent viscosity in disagreement with the simple hydrodynamic friction model. The correlation time (τ*) scaled by the free rotator correlatio...