One-Dimensional Chain Viologen-Based Lanthanide Multistimulus-Responsive Materials with Photochromism, Photoluminescence, Photomagnetism, and Ammonia/Amine Vapor Sensing.

In this work, a series of novel multistimulus-responsive lanthanide coordination polymers {[LnL(H 2 O) 4 ]Cl 3 ·3H 2 O} n (Ln = Dy, Tb, Eu) constructed using a dicarboxylic acid viologen derivative L (L = N , N '-4,4'-bipyridiniodipropionate) and LnCl 3 ·6H 2 O were prepared. All materials showed positive responses to UV light, and the photochromic phenomena accompanied by significant photoquenching of photoluminescence could be observed through a photoelectron transfer mechanism. Strikingly, the Dy analogue displayed photomagnetic behavior, as well as responded positively to small molecules of inorganic ammonia/organic amines. Furthermore, the good photoresponsive and ammonia/amine vapor-responsive properties of the Dy-based material were further fulfilled in dual-function papers involving erasable inkless printing and visual amine detection applications. This work aims to advance the development of multistimulus-responsive multifunctional materials incorporating viologen derivates and versatile lanthanide ions and further enriches the research in this field.