Zn-diarylethene organic framework for anticounterfeiting: Crystal structure, photochromism and fluorescence switch

A new photochromic metal-organic framework [ Zn(BCM) 2 (bpfb)] where H 2 BCM ​= ​1,2-bis(5-carboxylic acid-2-methylthien-3-yl)hexafluorocyclopentene, bpfb ​= ​N, N -bis-(4-pyridylformamide)-1,4-benzenediamine, was synthesized and characterized by Single Crystal X-ray Diffraction, Powder X-ray Diffraction, Elemental Analysis , Fourier Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA). [Zn(BCM) 2 (bpfb)] crystallizes in a monoclinic P2 1 /n space group. The Single crystal X-ray structure determination revealed a three dimensional (3D) coordination framework of dinuclear zinc clusters [Zn 2 (COO) 4 N 2 ] interconnected both BCM 2− and bpfb. And [Zn(BCM) 2 (bpfb)] exhibited reversible photochromism behavior derived from diarylethene BCM 2− ligand. Besides, [Zn(BCM) 2 (bpfb)] can be further used to photo-switch the luminescence emission, which can achieve precisely reading out and concealing information in reversible transformation.