Reversible Photochromic Coordination Polymer by Phototriggered Subtle Molecular Conformation Variations

Abstract

Photochromic materials are constructed with molecules accompanied by structural change after triggering by light, which are of great importance and necessity for various applications. However, because of space-confinement effects, molecule stacking of these photoresponsive chromophores within coordination polymers (CPs) always results in an efficiency decrement and a response delay, and this phenomenon will lead to a poor photochromic property. Herein, a CP (named CIT-E) with a 3-fold-interpenetrating network structure, which was prepared with (Z)-1,2-diphenyl-1,2-bis­[4-(pyridin-3-ylmethoxy)­phenyl]­ethene (1Z) and a CuI cluster, showed fast reversible photochromic behavior. Under UV-light illumination, the color of CIT-Z changed from pale yellow to reddish brown. With the illumination of green light, the polymer could return to its initial color within 10 s. To reveal the mechanism of reversible photochromic behavior of CIT-Z, single-crystal structures of each color state were fully studied, and other scientific study methods were also used, such as time-dependent density functional theory calculation and control experiments. It was found that, with light illumination, this behavior of CIT-Z was the result of a ligand-to-metal charge-transfer process, and this process was triggered by subtle molecular conformation variation of tetraphenylethylene. It should be noted that CIT-Z has high thermal and chemical stability, which are excellent advantages as smart photoresponsive materials. As a proof of concept, a uniform thin film with such a fascinating photochromic property allows applications in invisible anticounterfeiting and dynamic optical data storage. Overall, the present study opens up a new avenue toward reversible photochromic materials.

Efficient fluorescence-enhanced probe for cyanide ions based on a tetraphenylethene pyridine coordinated copper-iodide complex

“…S4†). 34 Powder X-ray diffraction pattern (PXRD) of the ligand and CIT-Z powder were compared with the simulated pattern generated by Mercury 4.1.0 software, and it was found that the main diffraction peaks in the CIT-Z test pattern match well with the simulated pattern (Fig. 2).…”

“…Herein, a CPs (named CIT-Z) was prepared using TPE pyridine derivative as an organic ligand and copper iodide as a metal center according to our previous work. 34 The CPs exhibits a two-dimensional triple-interpenetrating network structure with excellent chemical stability and optical properties. Based on its structural characteristics and the interaction between it and target analytes, CIT-Z can be utilized for detecting various pollutants in the environment.…”

One‐dimensional coordinated polymers of tetraphenylethene pyridine and copper‐iodide for fluorescence detection of nitroaromatic explosives

“…CIT‐E exhibits a one‐dimensional chain structure and demonstrates reversible force‐induced fluorescence enhancement properties, highlighting the crucial role of coordination effects and topological structures in the optical properties of CPs. Notably, CIT‐E shows reversible force‐induced fluorescence enhancement only, in contrast to our previous work involving CIT‐Z, which suggests the influence of the E/Z configuration of the ligand on the structure, properties, and applications of different CPs [26]. Moreover, CIT‐E demonstrates excellent thermal and chemical stability, making it suitable for detecting explosive analogs such as 2,4‐dinitroaniline.…”

“…The ligand TPE‐2by‐2‐E was synthesized according to previous work [26–28], and the synthesis route is shown in Supporting Information Figure S1. See the details in Figures S2–S4.…”

CuI-p-DPA coordination polymer isomers for “turn-on” fluorescence detection of thiophanate-methyl

“…3,4 Due to the structural diversity, luminescence properties and various coordination modes of CuI clusters, a large number of copper iodide complexes with various structures can be obtained after coordinating with organic ligands. 5 These diverse CPs can exhibit a wide range of properties, such as stimulus-response, 6 conductivity, 7 catalysis 8 and magnetic properties. 9 In addition, owing to the abundant reserves in nature and low price and toxicity of the metal copper, CuI CPs are very attractive from the economic and environmental perspectives.…”