[Zn(HPO3)(C11N2O2H12)] and [Zn3(H2O)(PO4)(HPO4)(C6H9N3O2)2 (C6H8N3O2)]: homochiral zinc phosphite/phosphate networks with biofunctional amino acids

Abstract

Two new homochiral inorganic–organic hybrid frameworks [Zn(HPO₃)(C₁₁N₂O₂H₁₂)] (denoted as ZnHPO-CJ56) and [Zn₃(H₂O)(PO₄)(HPO₄)(C₆H₉N₃O₂)₂(C₆H₈N₃O₂)] (denoted as ZnPO-CJ57) have been hydrothermally synthesized in the presence of chiral amino acids L-trypophan and L-histidine. Both of their inorganic networks are featured by one-dimensional (1D) edge-sharing Zn₂P₂ ladder-like chains. The amino acid molecules as the ligands are grafted onto two sides of the chain. Extensive N–H⋯O and O–H⋯O hydrogen bonds of host–guest are formed to stable the chiral structures of ZnHPO-CJ56 and ZnPO-CJ57. It is noteworthy that the original chirality of the amino acid molecules is maintained in the structures of the as-synthesized compounds, and the resulting crystals have an enantiometric excess, which is confirmed by the solid state vibrational circular dichroism (VCD). Their syntheses, structures, and luminescence properties have been studied in detail. The formation of such chiral one-dimensional structures with multi-amino acids might be potentially applied in chiral catalysis, biochemistry processes or as functional materials.