Elucidation of Chiral Symmetry Breaking in a Racemic Polymer System with Terahertz Vibrational Spectroscopy and Crystal Orbital Density Functional Theory

作者：Zhang Feng; Wang Houng Wei; Tominaga Keisuke^*; Hayashi Michitoshi^*; Lee Sunglin; Nishino Takashi^*

来源：Journal of Physical Chemistry Letters, 2016, 7(22): 4671-4676.

DOI：10.1021/acs.jpclett.6b02213

The conservation of chiral symmetry has been used as a fundamental rule to determine polymer packing conformations in racemic systems. We have illustrated, through the interplay of polarization terahertz (THz) spectroscopy and solid-state density functional theory, that the chiral symmetry is not conserved in a poly(lactic acid) stereocomplex (scPLA) system. Poly(L-lactic acid) (PLLA) displays a weaker violation of the 3, screw symmetry than poly(D-lactic acid) (PDLA) and possesses a stronger intramolecular vibrational energy, on average, in the low-frequency gamma-point phonon modes than does PDLA. Polarization THz spectroscopy adds a new dimension to polymer crystallography through which new phenomena are expected to be revealed.

• 出版日期2016-11-17