Awasthi Aashees, Shukla J P
Department of Physics, University of Lucknow, 226 007, Lucknow, India.
Ultrasonics. 2003 Aug;41(6):477-86. doi: 10.1016/s0041-624x(03)00127-6.
Complex formation in ternary liquid mixtures of dimethylsulfoxide (DMSO) with phenol and o-cresol in carbontetrachloride has been studied by measuring ultrasonic velocity at 2 MHz, in the concentration range of 0.019-0.162 (in mole fraction of DMSO) at varying temperatures of 20, 30 and 40 degrees C. Using measured values of ultrasonic velocity, other parameters such as adiabatic compressibility, intermolecular free length, molar sound velocity, molar compressibility, specific acoustic impedance and molar volume have been evaluated. These parameters have been utilized to study the solute-solute interactions in these systems. The ultrasonic velocity shows a maxima and adiabatic compressibility a corresponding minima as a function of concentration for these mixtures. The results indicate the occurrence of complex formation between unlike molecules through intermolecular hydrogen bonding between oxygen atom of DMSO molecule and hydrogen atom of phenol and o-cresol molecules. The excess values of adiabatic compressibility and intermolecular free length have also been evaluated. The variation of both these parameters with concentration also indicates the possibility of the complex formation in these systems. Further, to investigate the presence of O-HO bond complexes and the strength of molecular association with concentrations, the infrared spectra of both the systems, DMSO-phenol and DMSO-o-cresol, have been recorded for various concentrations at room temperature (20 degrees C). The results obtained using infrared spectroscopy for both the systems also support the occurrence of complex formation through intermolecular hydrogen bonding in these ternary liquid mixtures.
通过在20、30和40摄氏度的不同温度下，测量2MHz时的超声速度，研究了二甲基亚砜（DMSO）与苯酚和邻甲酚在四氯化碳中的三元液体混合物中的络合物形成情况，DMSO的浓度范围为0.019 - 0.162（摩尔分数）。利用测量得到的超声速度值，还评估了其他参数，如绝热压缩性、分子间自由长度、摩尔声速、摩尔压缩性、比声阻抗和摩尔体积。这些参数已被用于研究这些体系中的溶质 - 溶质相互作用。对于这些混合物，超声速度随浓度呈现最大值，而绝热压缩性则呈现相应的最小值。结果表明，通过DMSO分子的氧原子与苯酚和邻甲酚分子的氢原子之间的分子间氢键，不同分子之间发生了络合物形成。还评估了绝热压缩性和分子间自由长度的过量值。这两个参数随浓度的变化也表明了这些体系中形成络合物的可能性。此外，为了研究O - HO键络合物的存在以及分子缔合强度与浓度的关系，在室温（20摄氏度）下记录了DMSO - 苯酚和DMSO - 邻甲酚这两个体系在不同浓度下的红外光谱。使用红外光谱法对这两个体系获得的结果也支持了在这些三元液体混合物中通过分子间氢键形成络合物的现象。
