ИСТИНА

Fabricating of solid-supported porphyrin-based metal organic networks which are a new class of functional porous materials promising for various applications remains a challenging problem for supramolecular chemistry. We developed a new method for preparation of composites of graphene oxide (GO) and zinc tetra-substituted porphyrin SURMOFs, which are potentially useful as synergetic catalysts, on planar solids. The template GO monolayers were prepared through entropy-driven self-assembly at the hexane/water interface.[1] We studied systematically a series of the GO-associated SURMOFs assembled from variously substituted meso-carboxyphenyl/pyridyl porphyrins and zinc acetate vis layer-by-layer deposition onto the GO –decorated surfaces.[2] The microscopically flat GO template can initiate the growth of macroscopically uniform SURMOF films exhibiting well-resolved X-ray diffraction. By applying D’yakonov method, which has been previously used for the extraction of self-convolution of electron density in clay minerals, to the analysis of the experimental diffraction patterns of SURMOFs, we determined the relation between the structure of porphyrin linkers and the geometry of packing motives in the films. We showed that the packing of the SURMOFs differs significantly from that of bulk powders of similar composition because of steric limitations imposed on the assembly in 2D space. The results of microscopic examination of the SURMOFs suggest that the type of metal-to-linker chemical bonding dictates the morphology of the films with roughness varied depending on the linker chemistry. By using BET method measurements, we demonstrated the exceptionally large surface area and adsorption capacity of fabricated SURMOF films. Our results are useful for better understanding of the interplay between supramolecular ordering and surface-directed assembly in metal organic frameworks formed by large and rigid aromatic building blocks. The approach we used provides a basis for new types of self-assembled coordination structures integrated with solids through anchoring on the 2D carbon templates. Acknowledgements The work is supported by Russian Science Foundation (grant №16-13-10512).