HYBRID ORGANIC–INORGANIC ASSEMBLIES BASED ON COORDINATION METAL–LIGAND FRAGMENTS: SYNTHESIS, PROPERTIES, APPLICATION IN CHROMATOGRAPHY

Abstract

The data on the synthetic methods of metal-organic frameworks (MOF) based on the coordination compounds of metals, including germanium, with the polydentate aromatic acids, their properties and applications are systemised in the paper. The prospect of using such types of MOFs to determine the highly toxic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) has been identified. Due to their unique properties, including large surface area, uniformly structured nanoscale cavities, tunable pore sizes and thermal stability MOFs are promising materials for use in analytical chemistry. They have been used in air sampling, as a stationary phase in chromatography, and as sorbents for solid-phase extraction, solid-phase microextraction, and magnetic solid-phase extraction. Depending on the structure of the ligands, MOFs can provide molecular recognition through different types of interactions of a wide range of compounds, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pyrethroids, nitrosamines and parabens, that are immunosuppressors, endocrine disruptors and cancerogenic compounds. For example, MOFs adsorb hydrophobic organic compounds (e.g., PAHs, PCBs) due to π-π stacking and hydrophobic interactions with organic linkers. Whereas the extraction of organic compounds with hydrophilic groups (for example, nitrosamines) occurs due to electrostatic interaction and hydrogen bonds. The most effective methods of synthesis of the considered type MOF are hydro(solvo)thermal synthesis and mechanochemical methods modified by adding a small amount of solvents. The slow diffusion methods are advisable to use to obtain crystals suitable for single-crystal X-ray diffraction.