Researches on the construction of supramolecular helical chains in crystallized β-alaninium sulfate/ perchlorate compounds

A new compound, (H₂L)₂SO₄ (1) (HL = β-alanine), was synthesized and studied based on X-ray single crystal diffraction analysis. β-alanine molecular displays two kinds of molecule torsion geometries (I and II) in compound 1, which construct supramolecular Z-shaped chains and supramolecular helical chains respectively. Based on our understanding of the helical packing mechanism of β-alanine in compound 1, we predicted and found supramolecular helical chains in another compound H₂LClO₄ (2) for the first time, although the crystal data of compound 2 has been reported previously. The way of simple β-alanine self-organizing into supramolecular helical chains was discussed in detail by comparing the structure of the compound 1 and compound 2, which may be important for understanding the way of simple molecules self-organizing into supramolecular helical structure and offers a good case for achiral ligands to construct supramolecular helical chains.