In the last decade, metal organic frameworks (MOFs) have shown great prospective as new drug delivery systems (DDSs) due to their unique properties: these materials exhibit fascinating architectures, surfaces, composition, and a rich chemistry of these compounds. The DSSs allow the release of the active pharmaceutical ingredient to accomplish a desired therapeutic response. Over the past few decades, there has been exponential growth of many new classes of coordination polymers, and MOFs have gained popularity over other identified systems due to their higher biocompatibility and versatile loading capabilities. This review presents and assesses the most recent research, findings, and challenges associated with the use of MOFs as DDSs. Among the most commonly used MOFs for investigated-purpose MOFs, coordination polymers and metal complexes based on synthetic and natural polymers, are well known. Specific attention is given to the stimuli- and multistimuli-responsive MOFs-based DDSs. Of great interest in the COVID-19 pandemic is the use of MOFs for combination therapy and multimodal systems.

Synergetic effect of Zr4+ and borate in zirconium organoborate could significantly promote the Meerwein–Ponndorf–Verley reduction of various biomass-based carbonyl compounds.

This work deals with the synthesis and characterization of one-dimensional (1D) imidazole-containing etidronates, [M 2 (ETID)(Im) 3 ]· n H 2 O (M = Co 2+ and Ni 2+ ; n = 0, 1, 3) and [Zn 2 (ETID) 2 (H 2 O) 2 ](Im) 2 , as well as the corresponding Co 2+ /Ni 2+ solid solutions, to evaluate their properties as multipurpose materials for energy conversion processes. Depending on the water content, metal ions in the isostructural Co 2+ and Ni 2+ derivatives are octahedrally coordinated ( n = 3) or consist of octahedral together with dimeric trigonal bipyramidal ( n = 1) or square pyramidal ( n = 0) environments. The imidazole molecule acts as a ligand (Co 2+ , Ni 2+ derivatives) or charge-compensating protonated species (Zn 2+ derivative). For the latter, the proton conductivity is determined to be ∼6 × 10 –4 S·cm –1 at 80 °C and 95% relative humidity (RH). By pyrolyzing in 5%H 2 –Ar at 700–850 °C, core–shell electrocatalysts consisting of Co 2+ -, Ni 2+ -phosphides or Co 2+ /Ni 2+ -phosphide solid solution particles embedded in a N-doped carbon graphitic matrix are obtained, which exhibit improved catalytic performances compared to the non-N-doped carbon materials. Co 2+ phosphides consist of CoP and Co 2 P in variable proportions according to the used precursor and pyrolytic conditions. However, the Ni 2+ phosphide is composed of Ni 2 P exclusively at high temperatures. Exploration of the electrochemical activity of these metal phosphides toward the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) reveals that the anhydrous Co 2 (ETID)(Im) 3 pyrolyzed at 800 °C (CoP/Co 2 P = 80/20 wt %) is the most active trifunctional electrocatalyst, with good integrated capabilities as an anode for overall water splitting (cell voltage of 1.61 V) and potential application in Zn–air batteries. This solid also displays a moderate activity for the HER with an overpotential of 156 mV and a Tafel slope of 79.7 mV·dec –1 in 0.5 M H 2 SO 4 . Ni 2+ - and Co 2+ /Ni 2+ -phosphide solid solutions show lower electrochemical perform...

Due to the large amount of industrial activity during the last century, heavy metal contamination of the environment has become a serious problem. Therefore, it is important to develop new and efficient methods of heavy metals removal from aqueous solutions. In this respect, three phosphonate metal organic frameworks were obtained in our labs by the reaction of divalent inorganic salt (CoSO4·7H2O), phosphonic acid [phosphonoacetic (CP), N,N-bis(phosphonomethyl)glycine (Gly) and vinylphosphonic (VP)] in hydrothermal conditions. The synthesized compounds were characterized by FTIR, X-Ray crystallography scanning electron microscopy and thermogravimetric analysis. These materials were used in the removal process of lead ions from aqueous solutions in order to determine the possibilities of their use as adsorbent materials. The effect of pH, lead initial concentrations and contact time upon the adsorption properties were investigated. From the experimental data it can be observed that the Co-Gly material developed a higher adsorption capacity for lead metal ions than the Co-VP and Co-CP, increasing following Co-CP<Co-VP<Co-Gly trend.

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