Crystal engineering with alicyclic β-amino acids: Construction of hydrogen-bonded bilayers

The crystal structures of four homologous cis-alicyclic ß-amino acids present a new recurring layer pattern of hydrogen bonds. This pattern was derived from two one-dimensional patterns observed in related alicyclic 2-hydroxycarboxylic acid structures. Its robustness is demonstrated by the isostructurality of the four crystals. The hydrogen bonds arrange the molecules in bilayers in the solid phase. The pattern was stressed by variations of the molecules, i.e., by the introduction of a double bond, by the change between stereoisomers, and by the replacement of the simple alicyclic ring with a bicyclic one. These variations gradually weaken the correspondence of the actual structure to the original design.