Molecular Conformational Transition of Chiral Conjugated Enantiomer Dominated by the Wallach’s Rule

Comparison of raceme and homochiral analogues reveals that the racemic compounds appear to crystallize easily upon external thermal annealing, and show more stable morphology. These differences will induce the formation of planar conformation in a racemic crystalline film but absence in chiral enantiomers, confirmed the Wallach’s rule in controlling condensed structures, associated with the dense molecular packing.