A dual stimuli-responsive system with spectral response from UV to the visible region was constructed by introducing methyl viologen into a luminescent Eu-MOF with a compact packing mode.

A new type of electron transfer (ET) system was built via the combination of a highly stable MOF host framework and methyl viologen guest molecule. The π-stacking arrangements adjust the distance between the D–A components, contributing to the formation of an ultra long-lived charge separated state in the photo/thermo dual stimuli-responsive complex.

An air-stable photoresponsive viologen molecular system is constructed based on a three-fold accordion interpenetrating packing arrangement. The fluorescent modulation process is coupled with a photochromic reaction via energy and electron transfer between the adjacent donor and acceptor groups.