From Homogeneous to Heterogeneous catalysis: Use of Microporous Solids as Macroligands
Résumé
At the molecular scale, the integration of the catalytically active centers into a solid support without loss of performance compared to the homogeneous analog is still a major challenge. In this context, a molecularly defined support as macroligand, i.e. a solid acting like the ligand in the corresponding molecular complex, can be considered as a key to bridge the gap between molecular and heterogeneous catalysis. Metal-Organic Frameworks and purely organic microporous polymers are promising candidates. In particular, porous frameworks made by the repetition of a coordinating motif, like the bipyridine motif are of a high interest as far as bipyridines are widely used as chelating ligand for molecular catalysts.[1,2] We show that both homogeneous and heterogenized catalysts follow the same linear correlation between the electronic effect of the ligand, described by the Hammett parameter, and the catalytic activity as exemplified in two reactions. This correlation highlights the crucial impact of the local electronic environment surrounding the active catalytic center over the long-range framework structure of the porous support. The gap between molecular and heterogeneous catalysis has never been so close to being bridged. This work is carried out within the H-CCAT project that has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 720996. H-CCAT aims at the large scale production of MOF catalysts and at their use in the industrial production of pharmaceuticals.
[1] F. M. Wisser, P. Berruyer, L. Cardenas, Y. Mohr, E. A. Quadrelli, A. Lesage, D. Farrusseng, J. Canivet, ACS Catal., DOI: 10.1021/acscatal.7b03998 (2018)
[2] F. M. Wisser, Y. Mohr, E. A. Quadrelli, D. Farrusseng, J. Canivet, ChemCatChem, DOI: 10.1002/cctc.201701836 (2018)