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Dynamic Mirror‐Symmetry Breaking in Bicontinuous Cubic Phases
Author(s) -
Dressel Christian,
Liu Feng,
Prehm Marko,
Zeng Xiangbing,
Ungar Goran,
Tschierske Carsten
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201406907
Subject(s) - chirality (physics) , twist , phase (matter) , enantiomer , crystallography , homochirality , chemical physics , chiral symmetry breaking , mirror symmetry , symmetry (geometry) , chiral symmetry , materials science , condensed matter physics , symmetry breaking , physics , stereochemistry , chemistry , quantum mechanics , geometry , mathematics , nambu–jona lasinio model , quark
Chiral segregation of enantiomers or chiral conformers of achiral molecules during self‐assembly in well‐ordered crystalline superstructures has fascinated chemists since Pasteur. Here we report spontaneous mirror‐symmetry breaking in cubic phases formed by achiral multichain‐terminated diphenyl‐2,2′‐bithiophenes. It was found that stochastic symmetry breaking is a general phenomenon observed in bicontinuous cubic liquid crystal phases of achiral rod‐like compounds. In all compounds studied the ${{\it Im}\bar 3m}$ cubic phase is always chiral, while the ${Ia\bar 3d}$ phase is achiral. These intriguing observations are explained by propagation of homochiral helical twist across the entire networks through helix matching at network junctions. In the ${Ia\bar 3d}$ phase the opposing chiralities of the two networks cancel, but not so in the three‐networks ${{\it Im}\bar 3m}$ phase. The high twist in the ${{\it Im}\bar 3m}$ phase explains its previously unrecognized chirality, as well as the origin of this complex structure and the transitions between the different cubic phases.