Solid-state structure of N-o-, N-m-, and N-p-nitrophenyl-2,3,4-tri-O-acetyl-β-d-xylopyranosylamines

Comprehensive structural analyses were performed for N-o-, N-m-, and N-p-nitrophenyl-2,3,4-tri-O-acetyl-β-d-xylopyranosylamines. Single-crystal X-ray diffraction data were collected and revealed that one compound under investigation undergoes temperature-dependent polymorph transitions (crystal structures of three polymorphs were obtained). The number of molecules in the independent part of the crystal unit cells was in agreement with the number of resonances in solid-state 13C NMR spectra. Therefore, the compounds exist as single polymorphs at room temperature, as confirmed by powder X-ray diffraction measurements. Significant differences in 13C chemical shifts between solution and solid-state NMR for selected carbon atoms confirmed the existence of intra- and/or intermolecular interactions.