Double role of metalloporphyrins in catalytic bioinspired supramolecular metal-organic frameworks (SMOFs)

• Published in: IUCrJ Vol. 5; no. Pt 5; pp. 559 - 568
• Main Authors: Fidalgo-Marijuan, Arkaitz, Amayuelas, Eder, Barandika, Gotzone, Larrea, Edurne S, Bazán, Begoña, Urtiaga, Miren Karmele, Iglesias, Marta, Arriortua, María Isabel
• Format: Journal Article
• Language: English
• Published: England International Union of Crystallography 01-09-2018
• Subjects: Aldehydes; aldol condensations; Analysis; Cascade chemical reactions; Catalysis; Catalysts; Catalytic activity; Chemical properties; Chemical synthesis; Coordination compounds; Crystal structure; heterogeneous catalysts; Infrared spectroscopy; Knoevenagel condensations; Metal-organic frameworks; Metallography; metalloporphyrins; one-pot cascade reactions; Organometallic compounds; Oxidation; Porphyrins; Research Papers; Single crystals; Structure; Sulfonic acid; supramolecular MOFs; Thermal stability; Thermogravimetry; Transmission electron microscopy; X-ray diffraction; aldol condensations; heterogeneous catalysts; Knoevenagel condensations; one-pot cascade reactions; supramolecular MOFs; metalloporphyrins
• ISSN: 2052-2525; 2052-2525
• DOI: 10.1107/S2052252518007856

Heterogeneous catalysts are of great interest in many industrial processes for environmental reasons and, during recent years, a great effort has been devoted to obtain metal-organic frameworks (MOFs) with improved catalytic behaviour. Few supramolecular metal-organic frameworks (SMOFs) are stable under ambient conditions and those with anchored catalysts exhibit favourable properties. However, this paper presents an innovative approach that consists of using metal nodes as both structural synthons and catalysts. Regarding the latter, metalloporphyrins are suitable candidates to play both roles simultaneously. In fact, there are a number of papers that report coordination compounds based on metalloporphyrins exhibiting these features. Thus, the aim of this bioinspired work was to obtain stable SMOFs (at room temperature) based on metallo-porphyrins and explore their catalytic activity. This work reports the environmentally friendly microwave-assisted synthesis and characterization of the compound [H(bipy)]
[(MnTPPS)(H
O)
]·2bipy·14H
O (TPPS =
-tetra-phenyl-porphine-4,4',4'',4'''-tetra-sulfonic acid and bipy = 4,4'-bi-pyridine). This compound is the first example of an MnTPPS-based SMOF, as far as we are aware, and has been structurally and thermally characterized through single-crystal X-ray diffraction, IR spectroscopy, thermogravimetry and transmission electron microscopy. Additionally, this work explores not only the catalytic activity of this compound but also of the compounds μ-
-[FeTCPP]
·16DMF and [CoTPPS
(bipy)(H
O)
]·6H
O. The structural features of these supra-molecular materials, with accessible networks and high thermal stability, are responsible for their excellent behaviour as heterogeneous catalysts for different oxidation, condensation (aldol and Knoevenagel) and one-pot cascade reactions.