Synthesis of β-Aminophosphonates and Study of Their Acid-Base Properties and Phase Distribution in Water-Organic Solvent Systems

New and previously known β-aminoethylphosphonates were synthesized by addition of primary and secondary amines to vinylphosphonates, and their IR and NMR spectra were examined. Diethyl 2-diethylaminoethylphosphonate and diethyl 2-morpholinoethylphosphonate were found to be stronger bases than the corresponding aminomethylphosphonates, but all these are weaker bases than their precursors, nonphosphorylated amines. Distribution constants of β-aminophosphonates between water and some organic solvents were determined and compared with those of their α-amino homologs.     

Sorption–Spectrophotometric and Test Determination of Zinc(II) as the Mixed-Ligand Complex of 1,10-Phenanthroline and Bromophenol Blue

The interaction of Zn(II), Cd(II), and Pb(II) with 1,10-phenanthroline noncovalently immobilized on silica in the presence of Bromophenol Blue was studied. The optimum conditions of the reaction and the composition of mixed-ligand complexes that are formed at the surface were found, and a scheme was proposed for the interaction at the interface. A sorption–spectrophotometric procedure and a test scale were developed for the determination of zinc with detection limits of 0.011 and 0.018 mg/L, respectively. The procedure was used for the determination of labile zinc species in soil.     

Aminoanthraquinone derivatives based on p-tert-butylthiacalix[4]arene. Synthesis and fluorescence properties

A convenient procedure has been developed for the synthesis of p-tert-butylthiacalix[4]arene derivatives modified at the lower rim with anthraquinone fragments linked through acetamide spacers. The products showed moderate fluorescence in the region λ 520–620 nm.     

Reactions of 1,2-ethanedithiol and 2-mercaptoethanol with unsaturated derivatives of four-coordinate phosphorus acids

The reaction of 1,2-ethanedithiol with diethyl vinylphosphonate in the presence of EtONa occurs as the addition of the sulfhydryl group to the β-carbon atom of the substrate to give 1 : 1 and 1 : 2 adducts. The nucleophilic addition of 2-mercaptoethanol at the β position of the multiple bond of diethyl vinyl-, diethyl allenyl-, and diethyl prop-1-ynylphosphonates involves only the sulfhydryl group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2156–2159, October, 2004.     

Macrocycle-based oligo- and polylactides: synthesis and prospects of application

The review considers methods for modifying oligo- and polymers of lactic acid by macrocyclic moieties (cyclodextrin, tetrapyrrole, and calixarene) and the effect of modifiers on the complexing, thermal, and aggregation properties. Analytical characteristics of oligolactide-based sensors and biosensors are discussed, with particular emphasis on the mechanism of signal generation and the contribution of modified materials to the selectivity and sensitivity of analysis.

     

Reactions of diethyl 3-methylbuta-1,2-dienylphosphonate with 2-aminobenzothiazole

A reaction of diethyl 3-methylbuta-1,2-dienylphosphonate with 2-aminobenzothiazole afforded 1-diethoxyphosphoryl-2-(2-imino-2,3-dihydrobenzothiazol-3-yl)-3-methylbut-2-ene. Dedicated to the Corresponding Member of the Russian Academy of Sciences T. A. Mastryukova. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2607–2609, November, 2005.     

Synthesis of hydrosols of oxygen-containing cobalt compounds

A procedure is developed for the synthesis of hydrosols of oxygen-containing cobalt compounds. The hydrosols are stable to aggregation for several weeks in the absence of additional stabilizers. It is established that the synthesized hydrosols contain crystalline particles formed from a mixture of CoO(OH) and Co₃O₄. According to transmission electron microscopy data, the most probable diameter of the particles is about 30 nm. The hydrosols are stable to aggregation at pH 6.2?C8.0. In this pH range, the particles are positively charged and the values of their electrokinetic potential are no higher than 10 mV.