Alexander Pokutsa

National Academy of Sciences of Ukraine | ISP · L. M. Litvinenko Institute of Physical-Organic Chemistry and Coal Chemistry

A cheap, versatile and effective method of hornets elimination based on the contact of flying individuals with the 20-30% solution of NaOH is reported. Importantly, the insects survived from the contact with this basic solution transport the poison to the nest.

A surprising D12 symmetry inside-hive constructions of honey bees were disclosed. The well-established sensitivity of bees to the magnetic field led us to supposition that it may play a key role in steering of such regular architecture.

The effect of near‐UV irradiation on the oxygenation of toluene dissolved in MeCN was studied in a stainless‐steel reactor upon O2 bubbling at 80°C and 100°C and 10 atm using Co (acac)2 and 9‐mesityl‐2,7,10‐trimethylacridinium perchlorate (Me2Acr+–Mes ClO4−) as the catalyst and photocatalyst, respectively. In the absence of the process mediator N‐h...

The cyclohexane oxidation by H2O2 using VO(acac)2 as starting catalyst in the presence of oxalic acid (OA) was studied. The dissociation of OA and VO(oxalate) formed in situ by interaction of VO(acac)2 with OA is the essence of the electrical conductance G elevation (or vice versa 1/G dropping). As follows from the electronic and cyclic voltammetry...

Fascinating oscillations of color, kinetics of pH, cyclic voltammetry (CV) and UV‐vis spectra, ensued from supplementing of VO(acac)2‐acetonitrile solutions with micro‐amounts of H2O2, were greatly affected by the small additives of glyoxal and oxalic acid. Such effect was consisted in sufficient decreasing the sensitivity of samples by means of it...

The oxygenation of cyclohexane and toluene by O2 and H2O2 catalyzed by VO(acac)2 and Co(acac)2 was studied at 40–100 °C and 1–10 atm. Upon such conditions, the process can be remarkably (30× times) enhanced by the minute (6–15 mM) additives of oxalic acid (OxalH) or N-hydroxyphthalimide (NHPI). The revealed effect of OxalH on H2O2-piloted oxidation...

Cyclohexane oxidation by H2O2 to cyclohexanol, cyclohexanone, and cyclohexylhydroperoxide under mild (40 °C, 1 atm) conditions is significantly enhanced in the system composed of VO(acac)2 (starting catalyst) and small additives of oxalic acid (process promoter). In corroboration of this, several times higher yield of the desired products was obtai...

The efficiency of the vanadyl(IV)acetylacetonate (1)–catalyzed oxidation of cyclohexane by hydrogen peroxide in acetonitrile increased in the presence of oxalic acid (2). The addition of 2 leads to the substitution of acac ligands by oxalate resulting in formation of vanadyl(IV)oxalate (3). That promotes the formation of cyclohexanol, cyclohexanone...

Study the mild cyclohexane oxygenation using vanadyl(IV)acetylacetonate as the starting catalyst and H2O2 as the oxidant has shown that oxalic acid as activator alters the products ratio, increases yield and catalyst turnover number. According to the instrumental (ESI-MS, NMR, EPR, UV–vis, GC, pH, titrimetric) investigations both the parental VO(ac...

The effect of propionic aldehyde additives on the kinetics and mechanism of cyclohexane oxidation by molecular oxygen catalyzed by variable-valence metal salts is studied. The effect of the catalyst metal (M) on the rate of oxygen consumption, yield, and ratio of reaction products (cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide (CHHP), and p...

An [Fe(IV)(2)(μ-O)(2)] diamond core structure has been postulated for intermediate Q of soluble methane monooxygenase (sMMO-Q), the oxidant responsible for cleaving the strong C-H bond of methane and its hydroxylation. By extension, analogous species may be involved in the mechanisms of related diiron hydroxylases and desaturases. Because of the pa...

Vanadyl(IV)-acetylacetonate-catalyzed oxidation of cyclohexane with H(2)O(2), at 40 degrees C under air atmosphere, has been studied in the presence of small quantities of oxalic acid. The process efficiency is increased by this additive and depends on the nature of the solvent (MeCN >= MeOH > Me(2)CO >= 2-PrOH > EtOH). The relationships between th...

A new protocol for the effective oxidation of cyclohexane in acetonitrile at 40°C and atmospheric pressure into cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide using hydrogen peroxide as the oxidant, vanadyl(IV)-acetylacetonate as the catalyst, oxalic acid and glyoxal as additives is presented with some reaction mechanism proposals.

The kinetics of H2O2 cleavage catalyzed by cobalt(II)-acetylacetonate has been studied at 40 °C in water, acetic acid, acetonitrile, tetrahydrofuran, 2-propanol, t-butanol, morpholine, and 1,4-dioxane by kinetic and spectroscopic techniques. As revealed, the nature of the solvent has a decisive influence on process. Medium polarizability and polari...

The process of catalytic hydrogen peroxide decomposition in acetic acid in the presence of vanadyl and cobalt (II) acetylacetonates was studied using modern spectroscopic and kinetic techniques. The formation of intermediates during the catalytic decomposition of hydrogen peroxide in the presence of VO(acac)2 was observed using UV—Vis and ESR spect...

The experimental data on the effect of physicochemical properties of solvent on the rate of hydrogen peroxide decomposition catalyzed by cobalt ions were obtained using a method of adding inhibitors and were generalized quantitatively by the application of multiparametric linear equations.

Decomposition of hydrogen peroxide in organic hydrophilic solvents, catalyzed by cobalt(II) palmitate [Co(palm)2], was studied by the method of inhibitors.

Evidence of the promoted effect of dialdehyde (glyoxal) in VO(acac)2- and Co(acac)2-catalyzed oxidations of cyclohexane by H2O2 under ambient conditions is reported. The V-process leads to a mixture of cyclohexanone, cyclohexanol, and cyclohexyl hydroperoxide and TON up to 4400. The Co-process is much less active but leads selectively to cyclohexyl...

The effects of free-radical reaction inhibitors (InH), hydroquinone (HQ) and quinone (Q), on the oxidation of cyclohexane catalyzed by cobalt(II) acetate Co(OAc)2 · 4H2O and on the decomposition of hydrogen peroxide in acetic acid (HOAc) at 303 K were studied. It was found that an increase in the concentration of HQ in the starting reaction mixture...

The homogeneous catalytic oxidation of cyclohexane by molecular oxygen and hydrogen peroxide in a solution of acetic acid (HOAc) in the presence of cobalt(II) acetate Co(OAc)2 is studied. The high yields of cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide (0.10–0.15 mol/l) and the high rate of the process (w = 10–5–10–4 mol l–1 s–1) are ex...

The kinetics and mechanism of the liquid-phase oxidation of cyclohexane with molecular oxygen in the presence of the additives of propionic aldehyde are studied at 303.0, 322.5, and 341.5 K by measuring the rates of oxygen and propionic aldehyde consumption and the yields of the main reaction products (cyclohexanol (COL), cyclohexanone (CON), cyclo...

The efect of acetic acid (AA) on catalytic oxidation of cyclohexane in the liquid phase has been investigated. It was shown that a possible cause of an increase in the rate of the process in the presence of Co2+(Co3+) compounds and acetic acid is increase in the initiation rate due to formation of active (in decomposition into radicals) CHHP·Co2+(C...

The joint liquid-phase oxidation of cyclohexane and trichloroethylene, initiated with azodiisobutyronitrile and catalyzed with divalent cobalt stearate (348 and 373 K), was studied. It was shown by methods of gas-liquid chromatography that cyclohexyl hydroperoxide, cyclohexanol, and cyclohexanone are formed in parallel in chain propagation and term...

Liquid-phase initiation with azodiisobutyronitrile (348 K) of cooxidation of cyclohexanone (I) with cymene (II), ethylbenzene (III), toluene (IV), cyclohexanone (VI), dibenzyl ether (VI), cyclohexanone (VII), and tri- (VIII) and tetrachloroethylene (IX) was studied. Cross-over rate constants of the chain propogation and termination reactions were d...