Zinc(II) and Copper(II) Metal-Organic Frameworks Constructed from a Terphenyl-4,4′′-dicarboxylic Acid Derivative: Synthesis, Structure, and Catalytic Application in the Cyanosilylation of Aldehydes

• Published in: European journal of inorganic chemistry 2016-12, Vol.2016 (36), p.5557-5567
• Main Authors: Karmakar, Anirban, Paul, Anup, Rúbio, Guilherme M. D. M., Guedes da Silva, M. Fátima C., Pombeiro, Armando J. L.
• Format: Article
• Language: English
• Subjects: Aldehydes; Catalysis; Catalysts; Clusters; Copper; Cyanosilylation; Derivatives; Fourier transforms; Heterogeneous catalysis; Metal-organic frameworks; Synthesis (chemistry); Zinc
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201600902

Solvothermal reaction of zinc(II) and copper(II) salts with 3,3′′‐dipropoxy‐[1,1′:4′,1′′‐terphenyl]‐4,4′′‐dicarboxylic acid (H2L) gave rise to the 1D and 2D metal–organic frameworks (MOFs) [Zn(L)(dmf)2]n (1), [Zn2(L)(NO3)2(4,4′‐bipyridine)2]n·n(DMF) (2), [Cu(L)(H2O)2]n·2n(H2O) (3), and [Cu3(OH)2(L)2]n·n(H2O) (4), which were characterized by elemental analysis, FTIR spectroscopy, and X‐ray single‐crystal diffraction. MOFs 1 and 3 have zigzag‐ and linear‐type 1D structures, respectively, whereas 2 and 4 possess rectangular grid‐ and layer‐type 2D structures. In 2 and in 4, a dinuclear ZnII cluster (C2O4Zn2) and a trinuclear µ3‐hydroxo‐bridged CuII cluster [Cu3(OH)2]n, respectively, act as building block units. These frameworks act as heterogeneous catalysts (the Zn‐MOFs are more active than Cu‐MOFs, and 1 is the most efficient) for the cyanosilylation of aldehydes with trimethylsilyl cyanide at room temperature. These MOF‐based heterogeneous catalysts can be easily recovered and reused, at least over a few consecutive cycles, without losing activity. Metal–organic frameworks of ZnII and CuII act as recyclable heterogeneous catalysts for the cyanosilylation of aldehydes at room temperature.