Immobilization of Heterocycle-Appended Porphyrins on UiO-66 and UiO-67 MOFs

An approach to immobilization of heterocycle-appended porphyrins bearing one or two anchoring groups at the surface of UiO-66 and UiO-67 MOFs has been developed. For this purpose, carboxy-substituted porphyrin’s derivatives Ni-4 and Ni-5 have been synthesized for the first time. It has been shown that the presence of one anchoring carboxy group at the periphery of the porphyrin is insufficient for the efficient immobilization. At the same time, the prepared pyrazinoporphyrin bearing two carboxy groups is efficiently immobilized at the surface of the MOF particles in 1 : 16 ratio with respect to hexanuclear Zr(IV) node clusters. The post-synthetic modification has been found to be the most efficient approach to prepare the target hybrid materials. The prepared materials are completely characterized by means of powder X-ray diffraction, scanning electron microscopy, and UV-vis diffuse reflectance and IR spectroscopies.