(S)-1-[N-(Benzylidene)hydrazinylcarbonyl]-2-hydroxyethylcarbamate esters: layered structures created from X—H···O (X = N,O) hydrogen-bonds

Abstract

Abstract The molecular structures of tert-butyl (S)-2-hydroxy-[N-(substituted-benzylidene)hydrazinyl-carbonyl]-ethylcarbamates, C15H20N3O4X (3: X = H, o-OH, o-NO2, m-NO2 and p-CN), derived from L-serine, are formally rather similar. Despite the variation in substituent, X, tricälinic (3: X = H), (3: X = o-OH), (3: X = m-NO2)and(3: X = p-CN) are isostructural and exhibit, with minor variations, the same fundamental intermolecular O—H···O and N—H···O hydrogen-bond connectivity in two-dimensions in layers of molecules. In monoclinic(3: X = o-NO2), however, the oxygen atoms of the nitro group function as additional O—H···O and N—H···O hydrogen-bond acceptors resulting in a more complex form of two-dimensional connectivity.