In situ resolved ligand chirality in preparing a chiral 3D zinc–cyclopentane–tetracarboxylate based coordination polymer

Abstract

A new chiral, three-dimensional coordination polymer, [Zn₂(CPTC)(TBPE)(H₂O)]·1.75H₂O (FJU-5), (H₄CPTC = cyclopentane-1,2,3,4-tetracarboxylic acid, TBPE = trans-1,2-bis(4-pyridyl)-ethylene) belonging to the chiral space group P2₁2₁2₁ with an orthorhombic unit cell was prepared under pH controlled hydrothermal conditions. In situ resolved ligand chirality from the original meso-form of the CPTC ligand, which undergoes a configurational conversion during the synthesis of FJU-5, is responsible for the formation of the chiral pillared-layer 3D network. 1D hydrophilic channels consisting of guest water molecules are located within the chiral 3D network. The 3D framework of FJU-5 is highly robust and remains intact even after the removal of both the guest and coordinated water molecules by dehydration, as evidenced by powder X-ray diffraction and thermogravimetric analyses. The dehydration–moisture absorption behaviour of FJU-5 is reversible.