BGR MACROHETEROCYCLIC COMPOUNDS OF ASYMMETRIC STRUCTURE WITH THIADIAZOL FRAGMENTS. SYNTHESIS AND PROPERTIES

This communication is a continuation of the systematic research of the authors in the field of synthesis and study of the properties of macroheterocyclic compounds. The great potential for structural modification allows us to synthesize macroheterocyclic compounds that differ in composition and the nature of the heteroatoms that make up them and make this class of compounds promising from the point of view of the design for the preparation of substances with valuable practical properties. The interaction of N,N/-bis-(1-imino-2-phenyl-1H-indene-3-iliden)-1,4-phenylenediamine with 2,5-dimiano-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole the macroheterocyclic compounds of asymmetric structure were synthesized in the molar ratio of the initial substances. Macroheterocycles are powdered substances with different shades of red color, having melting and crystallization temperatures (investigated in the argon current), soluble in chloroform, DMF, acetone, ethanol. Purification was carried out by column chromatography on aluminum oxide of II degree of activity on Brockman (eluent acetone - chloroform, 1:9 by volume). Identification of synthesis products was performed by thin-layer chromatography on Silufol UV-254 plates (eluent – acetone - chloroform, 1:1 by volume). The obtained compounds were characterized by infrared and electron spectroscopy. The electronic absorption spectra were measured on a Hitachi U-2010 instrument in quartz cuvettes at 20 °C. IR spectra were obtained on the Avatar 360 FT-IR ESP device in KVG. Elemental analysis data were obtained using the CHNS-O Analyzer FlashEA of 1112 Series. A bathochromic shift of the absorption bands was noted when the compound with 1,3,4-thiadiazole was closed in a cycle. The spectral characteristics indicate that the molecules of the synthesized compounds do not have a flat structure and the absorption is due to individual fragments that are part of the molecules of the synthesized structures.

SYNTHESIS AND PROPERTIES OF MACROCYCLIC COMPOUNDS WITH FRAGMENT OF METHYLINDANDONE

The present communication is a continuation of the systematic studies of the authors in the field of synthesis and studying the properties of macroheterocyclic compounds, as large as possible structural modifications allow currently to synthesize macroheterocyclic compounds, differing in composition, the nature of their constituent heteroatoms and make this class of compounds promising from the point of view of directed synthesis to obtain materials with valuable practical properties. Condensation products and macroheterocyclic compounds of a symmetrical structure are synthesized by the interaction of diimine 2-methylindandione-1,3 with 2,4-diaminobenzenesulfonic acid and 3,5-diamino-1,2,4-thiadiazole in a molar ratio of 2:1. Condensation products constitute a powdery substance with different shades of red color, soluble in water and organic solvents of different nature. Macroheterocyclic compounds were synthesized with two ways. The first method is cyclization of compounds of structure 2:1 in a symmetric structure, and the second in a molar ratio of the starting materials. A purification was performed by column chromatography on alumina of II degree of activity by Brockmann eluent acetone - chloroform, 1:1 by volume. An identification of the synthesis products was performed by thin-layer chromatography on plates Silufol UV-254 (eluent – acetone - chloroform, 1:1 by volume). The compounds were characterized by data of IR, electronic and 1H NMR spectroscopy. Electronic absorption spectra were measured on instrument Hitachi U-2010 in quartz cuvettes at 20 °C. IR spectra were obtained on the device Avatar 360 FT-IR ESP in KBr. 1H NMR spectra of solutions of samples in acetone – D6 were recorded on device "AMD Brucker 500" with an internal standard of TMS. The data of elemental analysis obtained on the instrument CHNS-O Analyzer FlashEA 1112 Series. A hypsochromic shift of the absorption bands was observed upon closure in a cycle. The widened absorption bands in the visible part of the electron spectrum indicate that the molecules of synthesized compounds have a flat structure and the absorption due to individual fragments, which are part of molecules and single-chain pairing of the synthesized structures.Forcitation:Berezina G.R., Nikolaeva K.A. Synthesis and properties of macrocyclic compounds with fragment of methylindandone. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 29-34

Derivatization Ion Chromatography for the Determination of Monoethanolamine in Presence of Hydrazine in PHWR Steam-Water Circuits

A simple, rapid and accurate method for the determination of monoethanolamine (MEA) in PHWR steam-water circuits has been developed. MEA is added in the feed water to provide protection against corrosion while hydrazine is added to scavenge dissolved oxygen. The quantitative determination of MEA in presence of hydrazine was accomplished using derivatization ion chromatography with conductometric detection in nonsuppressed mode. A Metrosep cation 1-2 analytical column and a Metrosep cartridge were used for cation separation. A mixture of 4 mM tartaric acid, 20% acetone and 0.05 mM HNO3was used as eluent. Acetone in the mobile phase leads to the formation of different derivatives with MEA and hydrazine. The interferences due Na+and NH4 +were eliminated by adopting a simple pretreatment procedure employing OnGuard-H cartridge. The limit of detection limit of MEA was 0.1 μg mL−1and the relative standard deviation was 2% for the overall method. The recovery of MEA added was in the range 95%–102%. The method was applied to the determination of MEA in steam generator water samples.