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AbstractThe electroanalytical characteristics of an ion-selective electrode (ISE) with a membrane based on a supramolecular polymer composition containing polyvinyl chloride, o-nitrophenyl octyl ether plasticizer, tetradecyphosphonium pertechnetate ionophore, and a lipophilic additive of tetradecylphosphonium tetraphenyborate are studied. The limit of detection for the ISE in aqueous solutions containing KTcO4 was 2 × 10–7 M and the slope of the electrode function at 20°C was 58 ± 1 mV/pTc\\(O_4^ - \\). Potentiometric selectivity coefficients were determined for various anions. A correlation between the hydration energy ΔGhydr and selectivity coefficients calculated by the method of mixed solutions is observed. It was found that a change in the pH of the solution in the range 2–12 slightly affects the electrode potential when the concentration of Tc\\(O_4^ - \\) in the analyzed solution is 1 × 10–6–0.001 M. The behavior of the electrodes in strongly acidic solutions was studied.

The work summarizes the data on currently known dimeric boron cluster anions with the general formula [B20H18]2−. Their preparation, structure, and the methods of structural modification are considered. The data on the reactivity of boron dimeric clusters in redox, substitution, complexation, and condensation reactions are presented. The isomerism of dimeric polyhedral boron cluster anions associated with the formation of substituted derivatives and coordination compounds is considered. The methods of reversible transformation of isomers in salts and coordination compounds in solutions and single crystals are discussed.

AbstractThe reaction of sulfonium closo-decaborate derivatives containing carboxyl groups with sulfuryl chloride SO2Cl2 as a halogenating agent was studied. The reaction gave fully halogenated derivatives of the closo-decaborate anion, (n-Bu4N)[2-B10Cl9SR2] (R = –CH2COOEt, –CH2COOH), which was confirmed by 11B, 1H, and 13C NMR and IR spectral data. The structure of the [2-B10Cl9S(CH2COOEt)2]– anion was established using single crystal X-ray diffraction.

AbstractNew methods of creation of cyclic bridging and terminal exopolyhedral sulfur-containing substituents in the closo-decaborate anion have been suggested. It has been shown that the reaction of [B10H9SH]2– with 1,2-dibromoethane leads to crosslinking of two cluster anions to give the [B10H9S(CH2)4SB10H9]2– dimer. An analogous reaction with 1,4-dibromobutane yields a derivative with the cyclic tetrahydrothiophene substituent [B10H9S(CH2)4]–. Its interaction with tetrahydrothiophene in the presence of a small excess of trifluoroacetic acid leads to the formation of the neutral disubstituted derivative [B10H8(S(CH2)4)2].

AbstractThe use of a sulfonium closo-decaborate derivative [B10H9S(C18H37)2]– as an active component of a hybrid polymer membrane designed to create a potentiometric uranyl-selective sensor has been studied. The synthesis of this compound has been described, and the optimal composition of the suggested membrane composition has been determined. Electroanalytical characteristics of the fabricated potentiometric sensor have been determined. The detection limit for uranyl ions of this sensor was 4.5 × 10–7 mol/L. The new sensor is recommended for the quantitative determination of uranyl ions formed during the dissolution of various uranium-containing products.

The interaction of the [B10H10]2– and [B12H12]2– anions with aliphatic and aromatic nitro compounds (RNO2, where R = Et, n-Pr, i-Pr, tert-Bu, Ph) has been studied under irradiation with visible and UV light. It has been shown that, depending on the reaction conditions, both mono- and disubstituted nitro-closo-decaborates can be selectively obtained in yields up to 50%.

Undoped lithiation of stoichiometric spinel using lithium hydride LiH up to the composition Li2.25Mn2O4 was performed. A homogeneous material with a given Li: Mn ratio was obtained by mechanochemical activation with sequential annealing of a LiMn2O4–LiH mixture in a high-purity argon atmosphere and then in air or oxygen at 373–553 K.

Polymer compositions based on the ionic liquid tetradecylammonium triethylammonium-closododecaborate (TTCD) are proposed as the main components of membranes of potentiometric sensors (ion-selective electrodes) for determining ions [B12H11N(C2H5)3]−. Two types of polymer compositions are considered: conventional, polyvinyl chloride (PVC)-liquid ion-exchanger (solution of TTCD in o-nitrophenyl octyl ether) and another, PVC-TTCD (ionophore-plasticizer). The optimal composition of membranes for both types of electrodes are proposed, and their main electroanalytical parameters, such as selectivity, effect of pH, range of linear response, reproducibility, and stability of potential, were measured. A comparative analysis of the electroanalytical parameters of potentiometric sensors with membranes of two types is given. The detection limits for the electrodes of types I and II are 9 × 10−7 and 4 × 10−7 M. It is shown that [B12H11N(C2H5)3]− anions can be determined by potentiometric titration with indicator electrodes of different types.

Boron cluster compounds are inorganic polyhedral structures used in various fields, they have a wide range of different types of bioactivity and are perspective compounds for boron neutron capture therapy of cancer. Therefore, they require the development of various analytical techniques for qualitative and quantitative analysis and determination of their properties. Capillary electrophoresis (CE) is an interesting, universal method for analysis of charged substances. However, there is a fairly limited number of boron cluster compounds studies using CE. Here reports the possibility of a technically simple method of capillary zone electrophoresis analysis of boron clusters [B10H10]2– and some of its derivatives, as well as the [B12H12]2–. The possibility of anions analysis in normal and reverse polarity separation modes in the absence of capillary surface modifiers or capillary wall polymer coating has been demonstrated. Electrophoretic mobilities were determined for analyzed compounds. The presented work is a clear example of the fact that capillary electrophoresis can serve as a simple and convenient method for soluble and partially water-soluble boron cluster compounds analysis.

Cobalt(II) complexation with azaheterocyclic ligands L (L = 2,2'-bipyridyl, 1,10-phenanthroline, and 2,2'-bipyridylamine) in the presence of a monohydroxy-substituted derivative of the closo -dodecaborate anion [B 12 H 11 OH] 2– has been studied. Depending on the nature of the organic ligand and the synthesis conditions, coordination compounds [Co III (Bipy) 2 Cl 2 ] 2 [B 12 H 11 OH], [Co II (Phen) 3 ][B 12 H 11 OH] and [Co II (Bipy) 3 ][B 12 H 11 OH] with the boron cluster anion as a counterion, as well as the mixed-ligand complex [Co II (BPA) 2 Cl 2 ] of a known structure, have been isolated and characterized by X-ray diffraction. For the first time, a redox reaction leading to the formation of a cobalt(III) complex in air has been observed for a system containing cobalt(II) and a substituted derivative of the boron cluster anion without the introduction of additional oxidizing agents.