Reactions of the trimer of phosphonitrile chloride

Replacement of the chlorine atoms of the trimer of phosphonitrile chloride by piperidine has yielded derivatives with a degree of replacement ranging from one to six chlorine atoms. In the case of the replacement of two and four chlorine atoms, isomeric di- and tetrapiperidino derivatives of the trimer of phosphonitrile chloride have been isolated.For part IV, see [6].     

1H NMR study of the hetero-association of flavin-mononucleotide with mutagenic dyes: ethidium bromide and proflavine

The hetero-association of the vitamin B₂ derivative, flavin-mononucleotide (FMN), with a mutagenic dye, ethidium bromide (EB) or proflavine (PF), has been studied by 1D and 2D 500?MHz ¹H NMR spectroscopy. The variations of proton chemical shifts of both the vitamin and dye as a function of concentration and temperature were analysed in terms of the structural and thermodynamical properties of the FMN–EB and FMN–PF complexes in solution. The structures of the complexes were also investigated by observed intermolecular ROE contacts and molecular mechanics calculations. The results show that the 1?:?1 hetero-association complexes in solution are more stable than the self-association complexes, which is consistent with formation of an intermolecular hydrogen-bond in the hetero-complexes of FMN–EB and FMN–PF. Hence it is possible that the toxicity of aromatic molecules such as EB and PF may be reduced in vitro by the presence of FMN, partly because of the known antimutagenic action of FMN and partly because it has been shown in this work that there is an effective intermolecular association between the mutagens and the vitamin.     

Synthesis of 1-aminoanthrapyridones and their derivatives

1-Aminoanthrapyridones are obtained when 1-anthrapyridonylpyridinium chlorides are heated in high-boiling amines. The synthesis of a number of substituted N-chloroacetyl-1-aminoanthraquinones. 1-anthrapyridonylpyridinium chlorides. and 1-aminoanthrapyridones is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 12. pp. 1651–1655. December. 1972.     

Comparison of results of measuring acidity of aqueous salt solutions of HCl by electrometric and indicator methods

Conclusions A comparison of the results of measuring the acidity of aqueous salt solutions of HCl by the electrometric and indicator methods disclosed that the equation for the ionization of Hammett indicators should take into account the water that is firmly bonded to the proton and the ionized form of the base.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2381–2383, October, 1981.     

Flow-injection photometric determination of the phenol index of natural waters in the presence of humic acids

Different schemes were considered for extraction preconcentration in the flow-injection determination of a phenol index, the total concentration of phenol and its derivatives that react with 4-aminoantipyrine. Preference was given to the scheme of flow injection analysis with the direct introduction of an extractant into the mixed flow of a sample and a reagent solution followed by phase separation in a chromatomembrane cell. This allowed phenols to be determined in natural and purified waste waters in the concentration range 1.0 to 10.0 µg/L with an RSD 25% and a throughput of 15 samples an hour. The study of the effect of humic acids on the results of determining the phenol index of natural waters showed that humic acids were hydrolyzed to form compounds that made their own contributions to the phenol index which were difficult to take into account.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 1, 2005, pp. 79–84.Original Russian Text Copyright © 2005 by A. Moskvin, Mozzhukhin, Mukhina, L. Moskvin.