Photomechanical motion triggered by [2 + 2] cycloaddition as well as simultaneous photochromic and fluorescence changes has been achieved by introducing flexible methylene groups and cation–π interactions into a pyridinium-based coordination complex.

In this work, a copper-based coordination polymer of [Cu 3 (dhba) 2 (OH) 2 (H 2 O) 4 ] (Cu-dhba, H 2 dhba = 3,5-dinitro-4-hydroxybenzoic acid) has been constructed by the crystal-engineering approach, featuring a threedimensional quasi-diamond interpenetrated structure. Impressively, due to the introduction of the d−d transition of the Cu 2+ ion, Cu-dhba shows a broad absorption band with the maximum centered at the NIR section. As a result, Cudhba exhibits a remarkable photothermal conversion performance under 808 nm light; the temperature of the sample surface could be increased up to 115 °C within seconds. Benefiting from its high structure density and abundant hydrogen-bonding interactions, Cu-dhba shows no obvious performance decay after several photothermal cycling experiments. Moreover, due to the high density of energetic nitro groups periodically confined in its structure, Cu-dhba exhibits a drastic explosion under 808 nm laser irradiation, making Cu-dhba a promising laser-responsive energetic material.