A Novel Multichromic Cd(II) Coordination Polymer Based on a Viologen Ligand Exhibiting Multichroism, Aniline Detection and Luminescence Properties

As a powerful strategy to precisely fabricate multifunctional materials with unique optoelectronic properties, donor-acceptor (D-A) alignment, which integrates D-A pairs into the modular and versatile crystalline cation metal-organic frameworks (CMOFs) and cation coordination polymers (CCPs) is applied at the molecular level. In this paper, a photo- and thermochromic CCP, named [Cd (PTA)0.5(bcbpy)0.5Br] (1), was successfully produced by the self-assembly of a photo- and thermoactive 1,1'-bis((3-carboxylatobenzyl)-4,4'-bipyridinium)-dibromo ligand (H2bcbpy center dot 2Br) with cadmium chloride and terephthalic acid (PTA). This complex is characterized by single-crystal X-ray diffraction, powder X-ray diffraction and it exhibits high sensitivity to both heat and different illuminant. The exceptional difunctional characteristics of electron-transfer (ET) thermochromism and photochromism in 1 are mostly influenced by the photosensitivity and thermal sensitivity of H2bcbpy center dot 2Br. Otherwise, during the coloration-decoloration phase, there is a photoluminescence "on/off switch" which would direct the synthesis of new crystals.