Encapsulation of Aromatic Compounds and a Non-Aromatic Herbicide into a Gadolinium-Based Metal-Organic Framework via the Crystalline Sponge Method

The crystalline sponge method (CSM) is a procedure that has the potential to remove the need to have good-quality single crystals of the target compound by soaking said compound into a crystalline metal-organic framework (MOF). To increase the range of compounds that can be employed with the CSM, a range of different MOFs must be investigated. In this study we have explored the use of a lanthanide-based MOF, RUM-2, recently shown to have potential as a CSM host. Specifically, we have successfully formed five novel inclusion complexes with the four aromatic guests: 2-phenylethanol, benzyl acetate, benzyl benzoate, and vanillin and the non-aromatic herbicide molinate. A detailed analysis of the effect of size on the positions guest molecules sit within the pores of the MOF was performed. The pi center dot center dot center dot pi, CH center dot center dot center dot pi, hydrogen-bonding, and coordination host-guest and guest-guest interactions utilized in guest ordering were also investigated, and the disorder experienced by guest molecules was documented.