  MIL-100 (Fe) is a highly porous metal-organic framework (MOF), considered as
a promising carrier for drug delivery, and for gas separation and capture
applications. However, this functional material suffers from elaborated and
toxic synthesis that may hinder its biomedical use and large-scale production
to afford commercial applications. Herein, we report a green mechanochemical
water immersion approach to yield highly crystalline MIL100 (Fe) material.
Subsequently, we have harnessed this strategy for facile fabrication of
drug@MOF composite systems, comprising (guests) 5-fluorouracil, caffeine, or
aspirin encapsulated in the pores of (host) MIL-100 (Fe). Inelastic neutron
scattering was uniquely used to probe the guest host interactions arising from
pore confinement of the drug molecules, giving additional insights into the
reconstruction mechanism. Our results pave the way to the green production of
MIL type materials and bespoke guest-encapsulated composites by minimizing the
use of toxic chemicals, whilst enhancing energy efficiency and material's life
cycle central to biotechnological applications.
