Nanocrystalline M–MOF‐74 as Heterogeneous Catalysts in the Oxidation of Cyclohexene: Correlation of the Activity and Redox Potential

Abstract

In some aspects, the potential of metal–organic framework (MOF) materials as heterogeneous catalysts has been realized, at least in an academic context. However, one of their most promising catalytic properties, that is, the presence of open metal sites, is far from understood properly. In this work, a series of M–MOF‐74 (M=Mn, Co, Ni, Cu, Zn) materials, prepared under sustainable conditions, was tested systematically in the oxidation of cyclohexene, which can proceed by either radical or epoxidation routes. Under the optimized reaction conditions, the radical route is spontaneous to some extent and it is enhanced in the presence of any M–MOF‐74 that has a metal with a redox character but not Zn. However, the epoxidation of cyclohexene is also promoted by a redox catalyst in such a way that the conversion correlates qualitatively with the redox potential of the metal. Thus, for the first time, a chemical property of M is correlated with the catalytic activity of the M–MOF‐74 family.

New Trends in Oxidative Functionalization of Carbon–Hydrogen Bonds: A Review

“…Compound 16 exhibited activity in catalytic highly stereoselective oxidation of 1,2-cyclohexane with m-CPBA (Table 1). Metal-organic frameworks (MOFs), or porous coordination polymers, have attracted the attention of chemists [229][230][231][232][233]. Pombeiro, Martins, Guedes da Silva [234][235][236][237][238], Kirillov [234,235,[239][240][241], and other scientists [242] synthesized various polynuclear complexes, coordination polymers, and derived metal integrated mesoporous matrices and demonstrated high catalytic activity of these materials in oxidations with peroxides.…”

Direct Synthesis, Structural Features, and Enhanced Catalytic Activity of the Basolite F300-like Semiamorphous Fe-BTC Framework

“…7 thickness; FID detector) and total reflection X-ray fluorescence (TXRF) after being filtered (filter paper with pores of 0.45 µm). Identification of the non-commercial 2-cyclohexenyl peroxide product was done as described elsewhere.…”

“…[1][2][3][4][5][6] At the same time, the progress in their catalytic applications seems to be limited by certain aspects, such as their controversial stability in the reaction media, the lack of systematic studies or the subsequent scarce number of works affording some correlation between structural features of the MOF materials and their catalytic behavior. [7][8][9][10] Probably, the maximum exponent of this disparity between the possibilities and the so-far reduced development of MOFs as catalysts is found in the case of the Fe-BTC material, commercialized as Basolite F300. There are tens of publications remarking the notable catalytic performance of this material 2,[11][12][13][14][15][16][17][18][19][20][21][22] in reactions requiring either acidic or redox centers.…”

A Recyclable Cu-MOF-74 Catalyst for the Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

“…Nanocrystalline Cu-MOF-74 was prepared as described elsewhere [34] following a general method for synthesizing different M-MOF-74 materials at room temperature [35]. XRD powder patterns of nano- and micro-Cu-MOF-74 are depicted in Figure 12a.…”