Finally, to determine the volumetric response during this crystallographic shift, thermo-mechanical analysis was performed in a uniaxial loading experiment (TMA, Figure ). For CuBTC, we observe an expected featureless linear contraction, indicating no phase transitions, thermal decomposition, or other distinct reactions (Figure ). In contrast, IL@CuBTC exhibits a reversible expansion (contraction) reaction upon heating (cooling), with a height-change of ~1 %.