A homo-chiral helical coordination polymer constructed from an achiral ligand with excellent photo-physical properties and cell imaging application

Abstract

A one-dimensional homochiral coordination polymer (CP), [ZnCl₂(1,3-BPEB)]_n, (denoted as polymer 1) with helical structure was synthesized from ZnCl₂ and achiral ligand 1,3-bis[2-(4-pyridyl)ethenyl]benzene (1,3-BPEB). X-ray crystallography study reveals that CP 1 crystallizes in the tetragonal system P4₃2₁2 chiral space group. It exhibits good thermal stability and its skeleton can be maintained even after being heated to 400 °C. The UV-vis spectrum shows that 1 has a maximal absorption onset at 310 nm with a band gap of 3.1 eV, indicating a wide band-gap semiconductor. As expected, the participation of the fluorescent ligand 1,3-BPEB endows 1 with strong fluorescence emission. Nanoparticles with strong red fluorescence based on CP 1 can be applied to the field of biological imaging, achieving a good imaging effect.