A novel 2D chiral silver(I) coordination polymer assembled from 5-sulfosalicylic acid and (2S,4R)-4-hydroxyproline: Synthesis, crystal structure, HOMO–LUMO and NBO analysis

Abstract

A novel two-dimensional chiral silver(I) coordination polymer, namely {[Ag2(HSSA)(Hyp)]2·3H2O}n(1), where H3SSA=5-sulfosalicylic acid; Hyp=(2S,4R)-4-hydroxyproline, has been synthesized under classical conditions and structurally characterized by elemental analysis, infrared spectroscopy (IR), single crystal X-ray diffraction techniques. X-ray crystallographic study revealed that complex 1 crystallizes in chiral monoclinic C2 space group with −0.02(3) Flack parameter because it consists of only one enantiomer of 4-hydroxyproline. The 2D polymeric layers of 1 are expanded into a three-dimensional supramolecular network via classical intermolecular OH⋯O, NH⋯O and OH⋯S hydrogen bonding interactions. Interestingly, complex 1 exhibits rare CH⋯Ag interaction. In addition to these interactions, non-covalent supramolecular interactions such as Ag⋯C, Ag⋯π, π⋯π stacking interactions play in important role for the formation of 3D supramolecular framework. The HOMO–LUMO and NBO analysis of 2D coordination polymer have been studied by using the density functional theory (DFT) method.