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Structure and Stability of Quaternary Ammonium Interhalides: Experimental and Quantum-Chemical Study
Simonyan S. S. Kletskii M. E. Chernov'yants M. S. Gol'eva V. E. 《Russian Journal of General Chemistry》2003,73(4):575-582
The electronic structure of a series of ammonium interhalides [R1R2R3R4N]XI2, where R1 = CH3, C2H5, C3H7, F, H; R2 = R3 = R4 = CH3, H; X = Cl, Br, I, was studied by ab initio calculations (RHF/3-21G, RHF/HW, MP2/HW). The thermodynamic stability of these compounds correlates with the strength of the hydrogen bond N-H···X and three-center interhalide bond X-I-I. Calculations confirmed that, in polar solvents, these compounds preferably decompose to [R1R2R3R4N]+ and XI2
- (with subsequent decomposition of the anion), and in nonpolar solvents, to the neutral species [R1R2R3R4N]X and I2. The calculation results were compared to the experimental data obtained by single crystal X-ray diffraction, 1H NMR spectroscopy, and spectrophotometry. 相似文献
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M. S. Chernov'yants V. E. Gol'eva A. I. Pyshchev 《Journal of Analytical Chemistry》2003,58(2):139-143
The following biologically active diiodohalides of organic cations were studied: N-cetylpyridinium, trimethylbenzylammonium, triethylbenzylammonium, and N,N-dimethylmorpholinium diiodochlorides; N-cetylpyridinium, tetramethylammonium, tetrabutylammonium, and N,N-dimethylmorpholinium diiodobromides; and N,N-dimethylmorpholinium and butyroylcholinium triiodides. A simple and rapid procedure was proposed for the determination of the above compounds; it is based on the conversion of organic diiodohalides into the corresponding triiodides (300 nm 4 × 104; 370 nm 2 × 104) in the presence of excess potassium iodide (RSD 2%). An extraction–spectrophotometric method was developed for the quantitative determination of the biologically active compounds in pharmaceutical dosage forms based on their ion associates with anionic dyes, erythrosine (m
min = 1.25–3.30 g; RSD 3%) and Bromothymol Blue (m
min = 3.85 g; RSD = 3%), or a cationic dye—1,3-dimethyl-2-(4-morpholinophenyl)azobenzimidazolium phenylsulfate (m
min = 2.32–8.26 g; RSD 4%). The developed procedures were used for monitoring drug substances in model pharmaceutical preparations (RSD 4%). 相似文献
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Kazheva O. N. D'yachenko O. A. Chernov'yants M. S. Gol'eva V. E. Pyshchev A. I. 《Russian Journal of General Chemistry》2002,72(10):1521-1524
The complex formation in the system bis[2-(trimethylammonio)ethyl] succinate diodide-iodine involves no more than two iodine molecules. The crystal structure of the salt [(CH3)3N(CH2)2OCOCH2]2(I3)2 is formed by layers of inorganic anions (I3
-) and organic dications (centrosymmetric dications {[(CH3)3N · (CH2)2OCOCH2]+}2), evenly alternating along the a axis. The crystal structure of the salt [(CH3)3N(CH2)2·OCOCH2]2(I3)2(I2)0.5 is formed by organic and inorganic layers evenly alternating along the [011] diagonal, with a centrosymmetric iodine molecule. 相似文献
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M. S. Chernov'yants V. E. Gol'eva A. I. Pyshchev I. V. Evlashenkova 《Journal of Analytical Chemistry》2001,56(9):815-818
The following biologically active polyiodohalides of organic nitrogen bases were synthesized and studied: trimethylbenzylammonium, triethylbenzylammonium, and N-cetylpyridinium diiodochlorides; tetramethylammonium, tetrabutylammonium, and N-cetylpyridinium diiodobromides; and butylcholinium triiodide. A method for the identification of the above compounds was proposed based on the dependence of their thin-layer chromatographic mobility and IR, UV, and NMR spectrometric properties and on the nature of the organic cation and the structure of the polyiodide anion. Reversed-phase high-performance liquid chromatography in a 1 : 1 methanol–water mixture (pH 6.86) was used for determining the compounds under study. The developed procedure is characterized by high sensitivity (0.09–0.51 g) at RSD of no worse than 10%. 相似文献
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