A novel multichromic Zn(ii) cationic coordination polymer based on a new flexible viologen ligand exhibiting aniline detection in the solid state

Abstract

In this work, a novel multichromic cationic coordination polymer, named [Zn₄(BTC)₃(bcbpy)₂]·5H₂O (1), based on a new flexible viologen ligand 1,1′-bis(3-cyanobenzyl)-[4,4′-bipyridine]-1,1′-diium (H₂bcbpy·2Cl), Zn(NO₃)₂·6H₂O and pyromellitic acid (H₄BTC) was synthesized. Compound 1 has good photosensitive activity and can respond to sunlight at room temperature. The colour of compound 1 changes rapidly in response to UV light and blue ray irradiation within 5 s. We rarely obtained the crystal structures after irradiation under UV light and blue ray. At the same time, compound 1 shows the hydrochromism phenomenon when heated at 120 °C, and it also shows the ability of detecting aniline and NO²⁻ under low-concentration conditions (10⁻⁴ M).