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

Abstract

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 π···π, CH···π, 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.