Synthesis and Structure of Tri(p-tolyl)antimony Dichloride

Tri(p-tolyl)antimony dichloride was prepared by oxidation of tri(p-tolyl)stibine with chlorine or copper(II) chloride. As found by X-ray diffraction analysis, the antimony atom in tri(p-tolyl)antimony dichloride has the configuration of trigonal bipyramid with axially located chlorine atoms. The Sb-Cl and Sb-C distances are 2.476(2) and 2.104(7) Å, and the CSbC and ClSbCl angles are 120 and 180°, respectively.     

Synthesis and Structure of μ-Peroxybis[(4-bromophenoxy)tri(p-tolyl)antimony]

Russian Journal of General Chemistry -     

Synthesis and properties of 6-(p-tolyl)phenanthridines and 5,10-di(p-tolyl)diazapyrenes

10-Amino-, 10-phthalimido-, and 10-(p-toluamido)-6-(p-tolyl)phenanthridines and 5,10-di(ptolyl)-4,9-diazapyrene, the oxidation of which gives the 4,9-dioxide. were synthesized.     

Extraction studies of antimony bromide into benzene

Antimony(III) can be extracted rapidly and quantitatively into benzene from a 10 M H₂SO₄–0.03 M HBr system. The extracted antimony bromide has an antimony to bromine ratio of 1:3. Under the above optimum conditions for extraction of antimony, the behaviour of 35 other elements was studied; As³⁺, Ge⁴⁺, Se⁴⁺, and Sn²⁺ were extracted almost quantitatively, and the percentage extraction of Hg²⁺, Bi³⁺, and Te⁴⁺ was 74.1%, 10% and 5.5% respectively. The extraction of the elements into benzene from a 5 M H₂SO₄–0.01 M KI system was also investigated, A comparison of the two systems is given.     

Enhancement effect of sodium dodecyl benzene sulfonate (SDBS) and its application into voltammetric determination of telmisartan

A sensitive and rapid electrochemical method was developed for the determination of telmisartan based on the enhancement effect of sodium dodecyl benzene sulfonate (SDBS). In 0.1 mol L⁻¹ HClO₄ and in the presence of 7.5 × 10⁻⁵ mol L⁻¹ SDBS, a well-defined and sensitive oxidation peak was observed for telmisartan at the acetylene black (AB) paste electrode. However, the oxidation peak is poor-shaped and the peak current is very low in the absence of SDBS, suggesting that SDBS shows obvious enhancement effect for the determination of telmisartan. After all the experimental parameters were optimized, a sensitive and simple electrochemical method was developed for determining telmisartan. The oxidation peak current is proportional to the concentration of telmisartan over the range from 2.5 × 10⁻⁷ to 2.0 × 10⁻⁵ mol L⁻¹. The detection limit is 7.5 × 10⁻⁸ mol L⁻¹ after 2 min of accumulation. This new voltammetric method was successfully used to detect telmisartan in drugs.     

Synthesis and redox behavior of azulene-substituted benzene derivatives and (eta(5)-cyclopentadienyl)[tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes

1,2-Di(6-azulenyl)tetraphenylbenzenes and (6-azulenyl)pentaphenylbenzenes were synthesized by Diels-Alder reactions of di(6-azulenyl)acetylenes and 6-(phenylethynyl)azulenes with tetraphenylcyclopentadienone. Cobalt-mediated cyclooligomerization of mono- and di(6-azulenyl)acetylenes afforded 1,3,5- and 1,2,4-tri(6-azulenyl)benzene derivatives together with (eta(5)-cyclopentadienyl)[tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes. The redox behavior of these novel (6-azulenyl)benzene derivatives and [tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes was examined by cyclic voltammetry (CV). Mono(6-azulenyl)benzenes exhibited a reduction wave upon CV. In contrast, 1,2-di(6-azulenyl)benzenes showed a two-step reduction wave at the similar potential region upon CV, which revealed the formation of a dianion stabilized by 6-azulenyl substituents under electrochemical reduction conditions. Three 6-azulenyl substituents on benzene in a 1,2,4 relationship also increased electron-accepting properties because of the formation of a closed-shell dianionic structure, whereas 1,3,5-tri(6-azulenyl)benzenes were reduced stepwise.     

Polyelectrolyte influences on the trans–cis isomerization of sodium m-(4-ethoxyphenylazo)benzene sulfonate

Influences of microenvironment of various polyelectrolytes, i.e., ionene polymers and polyamine sulfones, on the photo- and/or thermal isomerization between the trans and cis forms of sodium m-(4-ethoxyphenylazo)benzene sulfonate (SEPS) were studied. 6,6-Ionene demonstrated larger enhancing effect on the cis–trans thermal isomerization than 3,3-ionene, which indicated that the micropolarity or the pH around the polymer is important. In the Arrhenius plots for both photo- and thermal isomerizations, deviations from the linearity were observed. In the former case, a sharp bend and the negative apparent activation energy were obtained at the high temperature. Furthermore, they were sensitively affected by the polyelectrolytes.     

New all-cis-tetra(p-tolyl)cyclotetrasiloxanetetraol and its functionalization

New all-cis-tetra(p-tolyl)cyclotetrasiloxanetetraol and its derivatives with Si(CH = CH₂)Me and Si(H)Me₂ groups have been prepared and characterized by IR and NMR spectroscopy, GPC, mass spectrometry, TGA and DSC. Molecular and crystalline structures of the tetraol and its derivative with four Si(CH = CH₂)Me groups have been determined by single-crystal X-ray diffraction.     

Solubility of antimony metal in molten antimony(III) chloride-aluminum chloride and antimony(III) chloride-cesium chloride mixtures

The solubility of antimony metal in molten SbCl₃AlCl₃ and SbCl₃CsCl is reported. Measurements were made at many compositions and temperatures within the following ranges: SbCl₃AlCl₃ system, 1–90 mol% AlCl₃ at 235–430°C; SbCl₃CsCl system, 0.5–25 mol % CsCl at 405°C, 45–80 mol % CsCl at 628°C and 60 mol % CsCl at 562–642°C. The solubility is attributed to the reversible reaction of antimony metal with antimony(III) in the melts to form two types of species with oxidation states below 3+. One type is stabilized in SbCl₃AlCl₃ melts at high pCl (pCl = − log[Cl⁻]) and the other is stabilized in SbCl₃CsCl melts with low pCl. Both types are present in melts with a high concentration of SbCl₃, but it is in such melts that antimony metal has its lowest solubility.     

Multiple morphological micelles formed from the self-assembly of poly(styrene)-b-poly(4-vinylpyridine) containing cobalt dodecyl benzene sulfonate

A series of supramolecular block copolymers were prepared using poly(styrene)-b-poly(4-vinylpyridine)(PS-b-P4VP) which coordinated with cobalt dodecyl benzene sulfonate (Co(DBS)₂) in tetrahydrofuran (THF). Fourier transformation infrared spectroscopy (FTIR), UV-vis absorption spectroscopy (UV) and differential scanning calorimetry (DSC) showed that Co(DBS)₂ coordinated to the lone electron pairs of the pyridine nitrogens in the P4VP block and leaded to complexes. The supramolecular block copolymers could self-assemble into nanosized micelles with different shapes and dimensions in THF, depending on the number of Co(DBS)₂ groups per 4-vinylpyridine (repeat unit was denoted by n) and the ratio between PS block length and P4VP block length. Transmission electron microscopy (TEM) results showed that when the number of repeat units of P4VP was more than that of PS, micelles with different interesting shapes such as spheres, rods, vesicles, large compound vesicles (LCVs) and the large compound micelles (LCMs) were observed if increasing the content of the Co(DBS)₂ in PS-b-P4VP copolymer/THF solution; When the number of repeat units of P4VP was less than that of PS, the micelle morphologies changed from spheres to rods, bi-layer, and LCMs if the Co(DBS)₂ content was increased progressively.     

Electrochemical interconversion of 1-(p-tolyl)-6-methyl-2,4-diphenylpyrimidinium perchlorate and 1-(p-tolyl)-6-methylene-2,4-diphenylpyrimidine

It is shown that reduction of the 6-methyl-1-(p-tolyl)-2,4-diphenylpyrimidinium cation proceeds in two one-electron stages. In the first stage, an unstable radical is formed, and in the second stage, an unstable anion. As a result of dehydrogenation of the radical, the anhydro base 6-methylene-1-p-tolyl-2,4-diphenyl-6H-pyrimidine is formed. Oxidation of this compound in a single one-electron stage forms an unstable cation radical, the hydrogenation of which leads to the original pyrimidinium cation. Data obtained by cyclic voltametry and electrosynthesis with subsequent identification of the products have shown that, the same as in the reaction with the hydroxide anion, the methyl-substituted pyrimidinium cation acts as a CH-acid.Rostov State University, Rostov-on-Don 344101, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 71–75, January, 1999.     

Differential determination of antimony(III) and antimony(V) by indirect spectrophotometry with chromium(VI) and diphenylcarbazide,after reduction of antimony(V)

Antimony(III) is determined indirectly through its reaction with excess of chromium(VI), the excess being quantified with diphenylcarbazide and measurement at 540 nm. Antimony(V) is reduced to antimony(III) with sodium sulfite in hydrochloric acid solution; excess of sulfite is eliminated by boiling. The subsequent determination of antimony(III) gives the concentration of total antimony, and antimony(V) is found from the difference between the results before and after reduction. Antimony in its different oxidation states can be determined in the range 0.04–0.7 mg l^?1 within an error of about 10%.