Preparation of Helical-Type Crystals from Tryptamine and Achiral Carboxylic Acids and their Enantiomorphous Control by Pseudo-Seeding

A series of helical-type co-crystals of tryptamine and achiral carboxylic acids were prepared by the self-assembly. Their crystal chirality is generated through the formation of a unidirectional two-fold helix between the two components. Several crystals of them having similar crystal structures were found to play the role of pseudo-seed crystals in chiral crystallization.