PREPARATION OF FINELY CRYSTALLINE BASIC BISMUTH (III) SUCCINATE BY THE REACTION OF BISMUTH OXIDE WITH SUCCINIC ACID SOLUTION

Using the methods of electron microscopy and grain size analysis the influence of the chemical prehistory of obtaining the precursor, monoclinic modification of α-Bi2O3, on the morphological features of the antibacterial drug, basic bismuth succinate, synthesized from it has been investigated. The basic bismuth succinate of the composition CH4(COOBiO)2 is shown to obtain expediently by the interaction of bismuth oxide α-Bi2O3 with a succinic acid solution at molar ratio of succinate ions to bismuth equal to 0.6-1.0 and process temperature of 60-80 °C. The composition of the precipitation products was confirmed by the data of X-ray phase and chemical analyses. Methods based on the oxidative thermolysis of bismuth oxonitrate of composition [Bi6O(OH)I(NO3)6.H2O, basic oxalate BiOHC2O4 and basic bismuth carbonate (BiO)2CO3, as well as alkaline treatment of solid [BiO(OH](NO)H2O or technological bismuth solutions in nitric acid were used for obtaining the monoclinic modification of bismuth oxide with different morphology. According to electron microscopy data, the α-Bi2O3 samples after oxidative thermolysis are a pseudomorphosis retaining the appearance and size of the original compounds, which subsequently determine the average size of particle aggregates formed in basic bismuth succinate powders. This is also confirmed by the data of the grain size analysis. The "geometric" method was used to calculate the average particle/aggregate size, standard deviation, and the degree of asymmetry of the distribution curve for obtained samples of basic bismuth succinate. It is shown that a sample of the basic bismuth succinate powder with the smallest particle size was obtained after treatment with succinic acid of bismuth oxide α-Bi2O3, which had been preliminarily precipitated by adding a technological bismuth nitric acid solution to sodium hydroxide solution.