Influence of Hydrogen Bond Donating Sites in UiO‐66 Metal‐Organic Framework for Highly Regioselective Methanolysis of Epoxides

Abstract

A Zr(IV)‐based UiO‐66 metal‐organic framework (MOF) (named 1) was synthesized by employing 1‐(aminomethyl)naphthalene‐2‐ol appended terephthalate linker and Zr(IV) salt via solvothermal method and subsequently characterized. Furthermore, the potential efficiency of activated (named 1′) form of as‐synthesized MOF was investigated as an organocatalyst for the ring‐opening of epoxide by methanol. The catalytic performance of 1 and 1′ was studied in the methanolysis of styrene oxide as a model substrate and the activity of 1′ was also examined with various alcohols. Under the optimized reaction conditions, the catalytic performance of 1′ reached 96 % conversion of styrene oxide to its corresponding product with 98 % regioselectivity. The reusability and stability of the catalyst were proved by recycling up to four runs in the methanolysis of styrene oxide. The Lewis acidity originating from metal nodes and hydrogen bond donating (HBD) sites in the linker is distributed homogeneously throughout the framework, thus playing crucial role in the activation of epoxide with easy accessibility.

Controlling the molecular diffusion in MOFs with the acidity of monocarboxylate modulators

“…In particular, heterogeneously catalysed synthesis of industrially relevant compounds, such as fine chemicals and pharmaceuticals, through the C-C and C-N bond-forming processes is a recent example where MOFs can bridge state-of-theart homogeneous catalysts with robust reusable solid catalysts. 39,42,43 Herein, we study the effects of the acidity and molecular size of modulators on UiO-66 properties in relation to its catalytic performance in the transformation of epoxides into amino alcohols via MOF-catalysed C-N bond formation, 36,[44][45][46][47] aiming to provide insights that will lead to the design of catalytic MOF systems based on their controlled properties. We have chosen UiO-66, a robust system that allows for precise control of its chemical reactivity through defect engineering.…”

A fluorescent zirconium organic framework displaying rapid and nanomolar level detection of Hg(ii) and nitroantibiotics

“…Hence, it can be concluded that both IITG-5 and IITG-5a have similar thermal stabilities to that of the other reported UiO-66 family of Zr-MOFs. 34,35 The experimental and theoretical weight losses due to the degradation of the organic linkers were ∼57% and ∼71%, respectively. Such a difference between experimental and theoretical weight losses clearly indicates that there are some linker defects in the MOF structure.…”

“…Therefore, the chemical stability of IITG-5a is comparable to other reported UiO-66 types of Zr-MOFs. 34,36 N 2 sorption analysis For the determination of surface area (BET) and pore volume of IITG-5a, the N 2 sorption analysis was performed at a temperature of −196 °C (Fig. S9, ESI †).…”

Relation Between Coordination and Lewis‐Acid Property of MOF‐Derived Mononuclear Zn(II) Catalyst Toward Epoxide Hydroxylation

“…Although Lewis bases as well show capability toward epoxide hydroxylation (Table 1, entries 11-15; and SI, Section 4), in this work, the coordination environment influenced Lewis-acidity dominates the catalytic activity on the basis of the abovementioned characterization and catalysis results. [46,47] Typically, the Lewis-acidic Zn 2 + -sites could be coordinated with the oxygen atom in the PO ring through an acid-base interaction, which in turn increases the electrophilicity of the neighbored carbon atoms in the epoxide. MeOH then attack the activated carbon atoms through either I or II pathway to give the main product and byproduct (Figure 5).…”