Large breathing of the MOF MIL-47(VIV) under mechanical pressure: a joint experimental–modelling exploration

A joint experimental–modelling study has demonstrated a large flexibility of the MIL-47(VIV) upon mechanical pressure which strongly deviates from its rigid behaviour in presence of guest molecules. A structural transition suspected by mercury intrusion and further confirmed by X-ray powder diffraction and molecular dynamics simulations, leads to a closed MIL-47(VIV) form never observed so far corresponding to a cell contraction of up to 43%. The microscopic key features that govern this transition are then elucidated from complementary Raman experiments.