Schrödle Simon, Hefter Glenn, Buchner Richard
Institute of Physical and Theoretical Chemistry, Universität Regensburg, Regensburg, Germany.
J Phys Chem B. 2007 May 31;111(21):5946-55. doi: 10.1021/jp0713413. Epub 2007 May 10.
Mixtures of water or D2O + 1,4-dioxane (DX) have been studied at 25 degrees C by dielectric relaxation spectroscopy over a wide range of frequencies (0.2 < or = nu/GHz < or = 89) for DX mole fractions 0 < or = x2 < or = 0.67. The spectra were best fitted by the sum of two Debye terms. The slower process was assigned to the cooperative relaxation of the hydrogen-bond network of water, whereas the faster mode reflects the dynamics of H2O molecules in a DX-rich environment. Analysis of the relaxation parameters revealed a largely microheterogeneous structure of the mixtures. The marked slowing-down of the cooperative mode on addition of DX is ascribed to the reduction of available H-bond acceptor sites and geometrical constraints on the H2O molecules in the water-rich regions.
在25摄氏度下，通过介电弛豫光谱法，在0.2≤ν/GHz≤89的宽频率范围内，对水或D2O与1,4 - 二氧六环（DX）的混合物进行了研究，DX的摩尔分数为0≤x2≤0.67。光谱通过两个德拜项的总和进行最佳拟合。较慢的过程归因于水的氢键网络的协同弛豫，而较快的模式反映了富含DX环境中H2O分子的动力学。对弛豫参数的分析揭示了混合物在很大程度上具有微观非均相结构。加入DX后协同模式的显著减慢归因于富水区域中可用氢键受体位点的减少以及对H2O分子的几何限制。
