Two-dimensional viologen-based lanthanide coordination polymers as multi-stimuli responsive materials to light and amines with a fluorescence response

Integrating multi-stimuli response properties in one molecule is challenging. This study presents two 2D polymers, [(Bpydp)Ln(H2O)(BDC)]<middle dot>NO3<middle dot>2H2O (Ln = Eu(1), Tb(2)), exhibiting rapid photo-responsiveness and the ability to detect specific small-molecule amines. In particular, complex 1 combines the functions of inkless printing, amine detection, anti-counterfeiting, and fluorescence recognition. Lanthanide-based materials exhibit rapid color change, light-modulated fluorescence, and selective volatile ammonia/amine detection via multi-pathway electron transfer.