All-in-one multicolor electrochromic devices on the basis of benzene-centered 1,3,5-tris(4-pyridylium) bromides

Tri(pyridinyl)pyridine Viologen-Based Kagome Dual Coordination Polymer with Selective Chromic Response to Soft X-ray and Volatile Organic Amines

“…As the extended viologen ligands, π-electron-deficient 2,4,6-tri­(pyridin-4-yl)­pyridine (tpp) derivatives with electron-withdrawing substituents can be good candidates as electron acceptors because their high degrees of conjugation are favorable for trapping and stabilizing the received electrons. , Owing to their stable reduction of radical cations to their neutral states, they can exhibit relatively fast response times and more than one reversible change in color during reduction processes. ,, Different from viologen-based materials, the major research on tpp-based materials has mainly focused on their electrochromic properties, and less attention has been paid to other stimuli-responsive performance such as photochromism, thermochromism, hydrochromism, piezochromism, or vaporchromism. , According to the Mulliken charge-transfer theory, the association of extended viologen ligands with electron-rich substrates can elicit the formation of many new stimuli-responsive compounds. On the basis of these considerations mentioned above and as a continuing work of our studies on the viologen-based coordination polymers, − we attempted to introduce such extended viologen to the manganese chloride system with the goal of developing multistimuli responsive coordination materials, taking into account the following factors: (a) Electron-deficient tpp derivatives can be used as stimuli-active units to construct stimuli-responsive materials.…”

“…Driven by the need to develop technologically smart materials for use in a variety of areas, including sensing, nanotechnology, coating, catalysis, optical switches, data storage, and controlled drug delivery vehicles, a number of stimuli-responsive materials have been successfully developed so far. − Among the stimuli-responsive materials, the chromic materials are vigorously sought-after for easily gathering information about the changing environment because color changes discerned with the naked eye can be connected to the chemical or physical stimuli. − In the past two decades, there has been an upsurge in the study of electron-transfer chromic materials due to their high chromic performances, which can exhibit reversible color changes upon external stimuli. − Viologen-based coordination polymers are typical electron-transfer chromic materials that can exhibit three oxidation states: neutral state, radical cation state, and divalent cation state. − The color change from divalent cation state to monovalent cation state is easily observed, but it is difficult to achieve multichromism for viologen-based materials . Recently, to enrich the chromic family, extended viologen-based coordination polymers with chromic performance have been successfully synthesized and provide new opportunities to obtain cost-effective chromic materials. − However, coordination polymers with extended viologen ligands are still quite limited, and the construction of such prominent materials with high chromic performance remains challenging.…”

“…15−19 The color change from divalent cation state to monovalent cation state is easily observed, but it is difficult to achieve multichromism for viologen-based materials. 20 Recently, to enrich the chromic family, extended viologen-based coordination polymers with chromic performance have been successfully synthesized and provide new opportunities to obtain cost-effective chromic materials. 21−25 However, coordination polymers with extended viologen ligands are still quite limited, and the construction of such prominent materials with high chromic performance remains challenging.…”

“…24,26,28 mainly focused on their electrochromic properties, and less attention has been paid to other stimuli-responsive performance such as photochromism, thermochromism, hydrochromism, piezochromism, or vaporchromism. 20,24 According to the Mulliken charge-transfer theory, the association of extended viologen ligands with electron-rich substrates can elicit the formation of many new stimuli-responsive compounds. On the basis of these considerations mentioned above and as a continuing work of our studies on the viologen-based coordination polymers, 29−31 we attempted to introduce such extended viologen to the manganese chloride system with the goal of developing multistimuli responsive coordination materials, taking into account the following factors: (a) Electron-deficient tpp derivatives can be used as stimuli-active units to construct stimuli-responsive materials.…”

The simultaneous modulation effect of N-substituents on the photochromic and electrochromic properties of naphthalenediimide-based coordination polymers

“…However, the ingenious modulation of the interfacial contacts for the construction of CPs with adjustable photochromic behaviors remains a huge challenge. In the past few decades, transition metal oxides, 39 small organic molecules, 40 conjugated polymers 41 and metal complexes 42 have been often used as electrochromic (EC) materials. Amorphous WO 3 43 is one of the most famous inorganic electrochromic materials, which has been applied in smart windows.…”