Induced vibrational circular dichroism and polymorphism of syndiotactic polystyrene.
Induced vibrational circular dichroism and polymorphism of syndiotactic polystyrene.
复制标题
间规聚苯乙烯的诱导振动圆二色性和多晶型现象。
作者：
Paola Rizzo;Michela Beltrani;G. Guerra
用振动圆二色性（VCD）测量和x射线衍射表征方法研究了非外消旋挥发性客体分子（香菜酮和柠檬烯）在非晶态共晶聚苯乙烯（s-PS）样品中引起的强烈圆二色性（CD）现象。此外，还研究了这些CD现象在热处理和溶剂处理后的稳定性，从而导致s-PS形成不同的多晶相。CD现象不仅在客体萃取后保持稳定，而且在导致螺旋γ相或跨平面α相的热退火过程后也保持稳定。相反，涉及至少部分溶解和结晶的溶剂处理导致螺旋ε相的CD现象减少，甚至涉及熔化和结晶的热处理导致β相的CD现象消失。结果表明，在s-PS薄膜中观察到的强烈CD现象是由于与天然共晶形态相关的超分子手性。
The intense circular dichroism (CD) phenomena, as induced in amorphous samples of syndiotactic polystyrene (s-PS) by cocrystallization with nonracemic volatile guest molecules (carvone and limonene), have been investigated by Vibrational Circular Dichroism (VCD) measurements and X-ray diffraction characterizations. Moreover, the stability of these CD phenomena after thermal and solvent treatments, leading to different polymorphic crystalline phases of s-PS, has been studied. The CD phenomena remain stable not only after guest extraction but also after thermal annealing procedures leading to the helical γ phase or to the transplanar α phase. The CD phenomena are instead reduced for the solvent treatments involving at least partial dissolution and crystallization that lead to the helical ε phases and even lost for thermal treatments involving melting and crystallization that lead to the β phase. The reported results indicate that the intense CD phenomena observed for s-PS films are due to a supramolecular chirality associated with the native cocrystal morphology.
影响因子：
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作者：
L. Guadagno;M. Raimondo;C. Silvestre;Ivano Immediata;Paola Rizzo;G. Guerra
通讯作者：
L. Guadagno;M. Raimondo;C. Silvestre;Ivano Immediata;Paola Rizzo;G. Guerra