Synthesis and Study of the Properties of Photocatalytic Compositions Based on Sro/Bi2O3 and (Bio)2CO3 Solid Solutions with Modifying Additives of Transition Metals Cu, Mn, Fe

In this work, we studied the effect of doping with d metals (Me: Mn, Fe, Cu) on the photocatalytic activity and optical properties of the hetero-structured, bismuth-containing Sr1-xMexBi4O7 / (BiO)2CO3 photo-catalyst, where x = 0.01–0.05. The stages of oxidative pyrolysis of precursor organometallic complexes with sorbitol by differential scanning calorimetry have been studied. The first stage of oxidative destruction is induced by the influence of nitrate-ion and terminates at temperatures below . The second stage of pyrolysis is associated with a further thermal degradation of sorbitol to pyrolytic carbon in the temperature range 113 - . The third stage 287–462°C is associated with the combustion of the formed pyrolytic carbon. The final stage of pyrolysis occurs in the temperature range of 462-with the formation of the target synthesis products. It has been established that Cu is the most effective dopant. In contrast to other metals, doping with copper results in the formation of a solid solution in the CuO-SrBi4O7 system. Compared to the initial SrBi4O7, as a result of doping Cu in an amount of 5 at. % the largest change in the band gap from 2.77 to 2.62 eV is achieved. The efficiency of photo-catalysis (estimated by the half-conversion of methylene blue) of the Cu0.05Sr0.95Bi4O7 / (BiO) 2CO3 composition turned out to be 2.3 times higher than the initial - undoped catalyst; and 3.1 times higher than in the non-catalytic process.

Iron Catalysis in Target Synthesis

The use of iron-catalysed organic transformations in the total syntheses of natural products has increased significantly. Iron-catalysed cross-coupling reactions are now widely applied in total syntheses and many other transformations, such as alkene functionalisation, oxidation, and cyclisation. The development of these processes, as well as many examples of their use in target synthesis, is presented here.1 Introduction2 Cross-Coupling Reactions3 Functionalisation of Unactivated Alkenes4 Carbocyclisation Reactions5 Oxidations6 Further Examples7 Conclusions

Rapid approach to complex boronic acids

The compatibility of free boronic acid building blocks in multicomponent reactions to readily create large libraries of diverse and complex small molecules was investigated. Traditionally, boronic acid synthesis is sequential, synthetically demanding, and time-consuming, which leads to high target synthesis times and low coverage of the boronic acid chemical space. We have performed the synthesis of large libraries of boronic acid derivatives based on multiple chemistries and building blocks using acoustic dispensing technology. The synthesis was performed on a nanomole scale with high synthesis success rates. The discovery of a protease inhibitor underscores the usefulness of the approach. Our acoustic dispensing–enabled chemistry paves the way to highly accelerated synthesis and miniaturized reaction scouting, allowing access to unprecedented boronic acid libraries.

Determination of the hexamethylenediamine impurity in polyhexamethylene guanidine hydrochloride by HPLC method

The object of the study was a polymeric biocidal material – polyhexamethyleneguanidine hydrochloride (PGMG GC). The purpose of this work was to develop a method for the quantitative determination of HMDA in the target synthesis product – PGMG GC by high-performance liquid chromatography (HPLC). Analytical data obtained during the assessment of the system’s precision, specificity, precision, accuracy and linearity of the method corresponded to the established acceptance criteria. The proposed analytical method of HMDA determination in polymeric PGMG GC is validated with respect to the indicated parameters and can be used to determine the HMDA content in the range 0,75–0,025 %.