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Induced vibrational circular dichroism and polymorphism of syndiotactic polystyrene
Author(s) -
Rizzo Paola,
Beltrani Michela,
Guerra Gaetano
Publication year - 2010
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20871
Subject(s) - chemistry , circular dichroism , vibrational circular dichroism , crystallization , chirality (physics) , crystallography , polystyrene , tacticity , supramolecular chirality , thermal stability , supramolecular chemistry , cocrystal , molecule , crystal structure , organic chemistry , polymer , hydrogen bond , chiral symmetry breaking , physics , quantum mechanics , nambu–jona lasinio model , polymerization , quark
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. Chirality, 2010. © 2010 Wiley‐Liss, Inc.