A new versatile crystalline sponge for organic structural analysis without the need for activation

Abstract

Crystalline sponges have made “crystallography without crystals” possible and have currently receive much attention, but it is difficult to apply them directly because of the tedious activation procedures. Therefore, it is important to prepare crystalline sponges that are highly stable and easy to operate. In this work, a new carbazole metal organic framework (CMOF) was synthesized and characterized via NMR, MS and X-ray diffraction analyses. The CMOF could directly capture liquids G1–G3, solids G4 and G5 in a THF solution, a mixture of G2 and G5, and monomers and mixed enantiomeric molecules G6–G9 without the need for activation. Furthermore, the CMOF could be used to identify the products from phytochemical isolation [cinnamaldehyde (G10)], organic synthesis [benzyl 2-hydroxybenzoate (G11)] and biosynthesis [veratryl alcohol (G12)] and monitor chemical reactions [acetylation of 4-allyl-2-methoxyphenol (G13) to 4-allyl-2-methoxyphenyl acetate (G14)]. The guests bound to the CMOF via five different modes (I–V). Thus, this work reports a new crystalline sponge that does not require activation and, most surprisingly, can capture guest molecules within one minute.