Highly stable isoreticular polypyrazolate based mofs

An important goal in devising technologically relevant metal-organic frameworks (MOFs) lies in the synthesis of robust networks capable of withstanding sustained use under extreme conditions. Together with this feature, another important challenge in this field is the development of stable structures including functional pending groups, with the aim of tuning pore properties (size and shape, volume and decoration), possibly enhancing uptake capacity and selectivity toward a targeted guest. Along this line, we have recently demonstrated that, using linear or triangular polytopic pyrazolate-based bridging ligands, some of the most stable porous metal-organic structures ever prepared can be isolated, as a result of the strong metal-pyrazolate framework bonds.1 We have now prepared two large series of isostructural pyrazolate-based MOFs (bearing NO2, NH2, OH, SO3H functional groups), reminiscent of NiBDP and ZnBDP parent structures [H2BDP = 1,4-bis(1H-pyrazol-4-yl)benzene]. In this contribution, our recent results upon these two families of MOFs will be presented, which include the description of i) the pre-synthesis functionalization of the four tagged-ligands, ii) the solvothermal synthesis of the related MOFs and iii) their extensive structural characterization by means of variable temperature X-ray powder diffraction analysis. Finally, the relationships between the nature of the organic residues and the structural and functional properties (gas sorption and separation) of the resulted materials will be highlighted.