Catalytic determination of selenium with a picrate-selective electrode

A method is described for the determination of selenium, based on its catalytic effect on the picrate—sulfide reaction. The determination involves a variable-time kinetic procedure using potentiometric monitoring with a picrate-selective electrode and automatic measurement of the time required for the potential to change by a preselected amount (5.0 mV). Selenium in the range 3–30 μg was determined with an average error of about 4% and relative standard deviations of about 2%. The reaction can also be followed spectrophotometrically.     

Trace analysis of fluorine by the Coulomb excitation method

The reaction¹⁹F(p, p′ γ)¹⁹F was used for the determination of fluorine concentration in biological materials such as lichen tissues and human bones. By means of this method, fluorine air contamination in the vicinity of aluminium works and the level of fluorine intoxication of exposed persons were investigated.     

Copolymerization reactivities and conductivities of some living polymers of p-substituted styrenes

A kinetic study in tetrahydrofuran of the addition of 1,1-diphenylethylene on para-substituted styrylcarbanions (with Cs⁺ as counterion) has given the reactivities of free ions and ion-pairs. For both species, the addition rate constant increased in the following sequence for the substituent of the phenyl ring: pH < p-CH₃ <p-CH₃O. It was also shown that in the same solvent, the dissociation constants of the polystyryl ion-pairs decreased with the electron-donating power of the substituent.     

Condensation metallosupramolecular polymers containing main-chain 2,2′-bipyridine and 2,2′:6′,2″-terpyridine moieties

Methods of preparing diverse metallosupramolecular polymers containing 2,2′-bipyridine and 2,2′:6′,2″-terpyridine moieties in main chains and their properties have been considered and analyzed. It has been shown that these polymers offer new possibilities for the design of materials possessing valuable specific characteristics.     

Analogs of pyrimidine mono- and polynucleotides

The corresponding monophosphates, cyclophosphates, and , -diphosphates were obtained by phosphorylation of 1-(1, 4-dihydroxy-2-pentyl) thymine, 1-(1, 3-dihydroxy-2-propyl) uracil, and their derivatives with selective protection of one of the hydroxyl groups. 2-Cyanoethyl phosphate (CEP) in the presence of N, N-dicyclohexylcarbodiimide (DCC), polyphosphoric acid, and pyrophosphoryl chloride were used as phosphorylating agents. The dependence of the yields of the products of phosphorylation of 1-(1, 4-dihydroxy-2-pentyl) thymine with CEP on the ratio of the reacting substances and the reaction time was studied. The monophosphates were cyclized under the influence of DCC. In the case of 1-(1, 3-dihydroxy-2-propyl) uracil 1-phosphate a dimeric phosphate was obtained in addition to a cyclophosphate. The acid hydrolysis of the cyclophosphates was investigated.See [1] for communication V; see [2] for a preliminary communication.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 678–683, May, 1978.