Hajlaoui Sondes, Chaabane Iskandar, Oueslati Abderrazak, Guidara Kamel, Bulou Alain
Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia.
Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 5;136 Pt B:547-52. doi: 10.1016/j.saa.2014.09.068. Epub 2014 Oct 2.
The phase transition at high temperature of bis-tetrapropylammoniumhexachlorostannate compound has been investigated by Raman spectroscopy as a function of temperature from 303 K to 393 K. While the bands mainly associated with the internal modes of the SnCl6 anions only undergo weak changes, strong evolutions of wavenumbers, widths and intensities of many lines associated with the organic cations are observed with discontinuities in the vicinity of the phase transition at 362 K. The most important changes are observed for two lines at 1137.5 cm(-1) and 1159.4 cm(-1) (at room temperature) issued from twisting of CH2 groups and skeletal deformation of the cations. The spectral characteristics of these lines are analyzed and consistently described in the framework of an order-disorder model for the phase transition. The temperature dependency of the reduced peak intensity allowed to determine the critical exponents and evolution of the correlation length on approaching the transition.
通过拉曼光谱研究了双四丙基氯化铵六氯锡酸盐化合物在高温下从303 K到393 K随温度变化的相变。虽然主要与SnCl6阴离子内模式相关的谱带仅发生微弱变化，但在362 K相变附近观察到许多与有机阳离子相关的谱线波数、宽度和强度有强烈变化且存在不连续性。对于由CH2基团扭曲和阳离子骨架变形产生的位于1137.5 cm(-1)和1159.4 cm(-1)（室温下）的两条谱线观察到了最重要的变化。分析了这些谱线的光谱特征，并在相变的有序-无序模型框架内进行了一致描述。约化峰强度的温度依赖性使得能够确定临界指数以及接近转变时相关长度的演变。
