An Unprecedented Homochiral Metal–Organic Framework Based on Achiral Nanosized Pyridine and V‑Shaped Polycarboxylate Acid Ligand

Abstract

A unique homochiral metal–organic framework has been successfully synthesized by solvothermal reaction of an achiral flexible V-shaped ligand and a nanosized π-electron-deficient pyridine ligand based on cobalt­(II) salt, [Co­(L)­(DPNDI)_0.5]_<i>n</i> (<b>1</b>) (H₂L = 4,4′-dicarboxydiphenylamine, DPNDI = <i>N</i>,<i>N</i>′-di-(4-pyridyl)-1,4,5,8-naphthalenediimide); the helixes assembled by H₂L and cobalt­(II) paddle-wheel centers are left-handed and transform the framework to chiral. Also, the inserting of the DPNDI transforms the original <b>dia</b> net constructed by H₂L and cobalt­(II) paddle-wheel centers to a 3-fold <b>jsm</b> net. This is the first example of interpenetrated <b>jsm</b> net. In addition, the chiral property of bulk products is confirmed by circular dichroism spectra (CD), and the thermal stability and the magnetic properties are also investigated