de Toledo T A, da Costa R C, Al-Maqtari H M, Jamalis J, Pizani P S
Universidade Federal de São Carlos, Departamento de Física, São Carlos, SP, 13565-905, Brazil; Universidade de Cuiabá, Faculdade de Engenharia, Campus Barão, Cuiabá, MT 78005-300, Brazil.
Universidade Federal de São Carlos, Departamento de Física, São Carlos, SP, 13565-905, Brazil; Universidade Federal de Campina Grande, Centro de Ciências e Tecnologia Agroalimentar, Pombal, PB 58840-000, Brazil.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Jun 5;180:9-17. doi: 10.1016/j.saa.2017.02.051. Epub 2017 Feb 24.
The heterocyclic chalcone containing thiophene ring 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one, CHClOS was synthesized and investigated using experimental techniques such as nuclear magnetic resonance (H and C NMR), Fourier transform infrared spectroscopy (FTIR) at room temperature, differential scanning calorimeter (DSC) from room temperature to 500K and Raman scattering at the temperature range 10-413K in order to study its structure and vibrational properties as well as stability and possible phase transition. Density functional theory (DFT) calculations were performed to determine the vibrational spectrum viewing to improve the knowledge of the material properties. A reasonable agreement was observed between theoretical and experimental Raman spectrum taken at 10K since anharmonic effects of the molecular motion is reduced at low temperatures, leading to a more comprehensive assignment of the vibrational modes. Increasing the temperature up to 393K, was observed the typical phonon anharmonicity behavior associated to changes in the Raman line intensities, line-widths and red-shift, in special in the external mode region, whereas the internal modes region remains almost unchanged due its strong chemical bonds. Furthermore, CHClOS goes to melting phase transition in the temperature range 393-403K and then sublimates in the temperature range 403-413K. This is denounced by the disappearance of the external modes and the absence of internal modes in the Raman spectra, in accordance with DSC curve. The enthalpy (ΔH) obtained from the integration of the endothermic peak in DSC curve centered at 397K is founded to be 121.5J/g.
合成了含噻吩环的杂环查尔酮1-(4-氯苯基)-3-(2-噻吩基)丙-2-烯-1-酮（CHClOS），并采用核磁共振（氢谱和碳谱）、室温傅里叶变换红外光谱（FTIR）、室温至500K的差示扫描量热法（DSC）以及10 - 413K温度范围内的拉曼散射等实验技术进行研究，以探究其结构、振动性质、稳定性及可能的相变。进行了密度泛函理论（DFT）计算以确定振动光谱，旨在增进对材料性质的了解。由于低温下分子运动的非谐效应降低，使得在10K下测得的理论拉曼光谱与实验拉曼光谱之间观察到合理的一致性，从而能够更全面地归属振动模式。升温至393K时，观察到与拉曼谱线强度、线宽和红移变化相关的典型声子非谐行为，特别是在外模式区域，而内模式区域由于其强化学键几乎保持不变。此外，CHClOS在393 - 403K温度范围内发生熔化相变，然后在403 - 413K温度范围内升华。这通过拉曼光谱中外模式的消失和内模式的缺失得以证实，与DSC曲线一致。从DSC曲线中以397K为中心的吸热峰积分得到的焓（ΔH）为121.5J/g。
