Tuning fluorescence sensing and heterogeneous catalytic activities of highly stable metal organic frameworks through linker design

Abstract

In this work, a new thiophene-2-carboxamide-functionalized Zr-UiO-66 MOF (4) was synthesized by employing a traditional solvothermal procedure. Figure 11 shows that material 4 has very good crystallinity and it preserves its structural framework even after activation procedure. Compound 4 displayed high thermal (up to 340 °C under an Aratmosphere) and chemical stability (in water, 1 M HCl, and acetic acid). The nitrogen physisorption measurement with the activated form of 4 (denoted 4and#8242;) exhibited a BET surface area of 781 m2/g despite attachment of a bulky side chain with the linker molecule.Compound 4and#8242; was able to catalyze the ring-opening reaction of epoxides with amines, heterogeneously. Catalyst 4and#8242; exhibited significant yields as well as broad substrate scope in the ring-opening of epoxides utilizing amines. It also displayed better catalytic performance in comparison to known MOF catalysts such as Cu3(BTC)2, Fe(BTC) (BTC: 1, 3, 5-benzenetricarboxylate) and Zr-UiO-66 (Figure 12). Control experiments were performed with the corresponding free linker, Zr(IV) salt and without catalyst 4and#8242;, confirming the exclusive role of 4and#8242; in the catalytic reaction (Figure 12). The reusability characteristics of catalyst 4and#8242; was established for up to five consecutive catalytic cycles. The synthesis and characterization of material 4 and 4and#8242; and mechanism (scheme 2) of the catalysis reaction were studied elaborately...