Bioinspired metalloporphyrin-based supramolecular MOFs have been successfully tested for heterogeneous catalytic applications.

Heterogeneous catalysts are a great bet for green chemistry in many industrial processes and, in the past decade, promising results have been achieved in order to improve the catalytic activity of Metal Organic Frameworks (MOFs). Accordingly, porphyrins make possible to design new coordination polymers with better properties, taking into account the important functions they develop in nature. In this sense, porphyrin-based MOFs are becoming very relevant in heterogeneous catalysis. Thus, the aim of this work was obtaining metalloporphyrinic MOFs exhibiting catalytic activity. Studying the effect of dimensionality on the MOF properties (including thermal stability and catalytic activity), in this work we study two catalysts with different dimensionalities, 3D [Ni5(H2TCPP)2O(H2O)4]·nS (1) and 0D [Cu(H4TCPP)]·6DMF (2) (where H6TCPP is meso-tetra(4-carboxyphenyl)porphyrin, DMF is N,N-dimethylformamide and S is the solvent). The structural features of both compounds, combined with their high thermal stability and accessible networks, are responsible for the excellent behaviour as heterogeneous catalysts. It is worth mentioning that significant reduction in reaction time compared to other reported catalysts has been observed. The recyclability of one of the herein studied porphyrin-based MOFs is outstanding. Further structural and thermal characterization has been carried out by means of single crystal X-ray diffraction, IR spectroscopy, thermogravimetry (TG), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM).

Compound 1 [Cu 24 (m-BDC) 24 (DMF) 20 (H 2 O) 4 ]·24DMF·40H 2 O (m-BDC is 1,3-benzenedicarboxylate and DMF is N,N-dimethylformamide) has been synthesized and structurally characterized by X-ray diffraction. It consists of Cu 24 -clusters arranged in such a way that 12 dimers are connected through m-BDC ligands. The clusters exhibit an internal cavity where crystallization molecules of DMF and water 10 are located. Additionally, there are guest DMF and water molecules in the voids generated by the 3D packing of the Cu 24 -clusters. The thermal stability of compound 1 has been also characterized, concluding that hydrogen bonds between solvent molecules are responsible for the robustness of the network. Compound 1 is similar to other seven compounds found in literature. This work is focused on the crystallochemical comparison of these compounds, which concludes that there are two mother 15 structures related to the hexagonal and cubic close packing of polyhedra, respectively. Derivative compounds are produced by the presence of different solvent molecules (differences affecting both the nature and the number of the guest molecules).

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