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A study of chlorination of molybdenum and tungsten with gaseous chlorine in dimethylformamide (DMF) has shown that water additives substantially accelerate the transition of these metals to the solution [1].Data on strong intermolecular interactions between water and DMF, resulting in the formation of wateramide complexes with various compositions, have been reported in [2]. It was shown that mixing of ç 2 é and DMF is accompanied by rupture of some hydrogen bonds between water molecules and by formation of éç ··· é hydrogen bonds between the carbonyl oxygen atoms of DMF and water molecules. The greatest number of these bonds is formed when the mole fraction of DMF in the aqueous solution is 0.3-0.35. This gives rise to a definite structure that can be easily rearranged due to various factors, for example, temperature variation, the addition of electrolytes, and so on.In the presence of gaseous chlorine, the addition of water induces the formation of HCl and HOCl in the system. Hydrogen chloride is known to be highly soluble in DMF up to concentrations markedly exceeding an equimolar ratio in the DMF-HCl system. The formation of complexes whose composition and structure determine the catalytic properties of solutions of HCl in DMF was established [3].This paper presents a detailed study of Re, Mo, and W chlorination in the DMF-H 2 é medium. EXPERIMENTALAnalytical grade Mo, W, and Re as powders with particle size of not more than 0.05 mm were used to study the chlorination process. Reagent grade dimethylformamide was purified by fractional distillation, the product quality being checked by IR spectroscopy and gas chromatography.The chlorination of metals was carried out by a reported procedure [1,4]. Water was added to DMF just before chlorination.The IR spectra of solutions obtained after chlorination and of the crystals that precipitate after keeping these solutions at room temperature (as mineral oil mulls) were recorded on a Nexus FT IR spectrometer in the 400-4000 cm -1 region.The chemical analysis of the crystals for carbon, hydrogen, and nitrogen was performed on an EA-1108 Carlo Erba CHNS analyzer (determination accuracy of no less than 0.3%); chlorine was determined by the Volhard method.X-ray diffraction analysis of the crystals was performed on a Bruker AXS Smart 1000 diffractometer at 240 K. RESULTS AND DISCUSSIONThe results of chlorination of Re, Mo, and W in DMF-H 2 é mixtures of various compositions are presented in the table. It can be seen that an increase in the water content in the solvent to 10% results in a higher degree of transition of all metals to the solution. On further increase in the water content, the amount of rhenium that passes to the solution continues to increase, whereas the amounts of molybdenum and tungsten decrease. Thus, the degree of metal dissolution decreases in the sequence Re > Mo > W. In the absence of ç 2 é , the proportions of tungsten and rhenium dissolved at room temperature are virtually equal and amount to 3%, whereas after the addition of 20% water, the proporti...

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The article presents a comparative retrospective analysis of clinical, laboratory data and outcomes in 39 patients with severe COVID-19 complicated by acute respiratory distress syndrome, who received high-flow oxygen therapy. Of which, 19 patients additionally received 75 mg of inhaled surfactant BL twice daily for 5 days using a nebulizer. As a result, mortality rate in the group of patients receiving surfactant was 10.5%, while in the standard therapy group — 50%; the number of patients transferred to the mechanical ventilation was 21% and 70%, respectively. As the patients receiving the surfactant were injected with COVID-19 hyperimmune convalescent plasma and monoclonal antibodies to interleukin-6 receptors more often than those from the control group, we recalculated the results regardless of these patients. However, a significant difference between the mechanical ventilation rate (2.5 times less often in the surfactant group) and mortality rate (3.5 times less in the surfactant group) was observed. The duration of hospitalization and stay at the intensive care unit was not significantly different between patients with and without surfactant treatment. Inhalation therapy with surfactant BL was well tolerated even by patients with chronic obstructive pulmonary disease. In no case did therapy have to be stopped due to side effects, the most common of which was coughing during inhalation. This retrospective analysis shows that the prescription of an inhaled surfactant prior to transferring patients to mechanical ventilation can prevent the progression of respiratory failure, put down mechanical ventilation, and improve survival.