2-Azidomethyl-5-ethynylfuran, a new ambivalent compound with both azide and alkyne moieties that can be used as a self-clickable monomer, is synthesized starting directly from renewable biomass. The reactivity of the azide group linked to furfural is tested via the efficient preparation of a broad range of furfural-containing triazoles in good to excellent yields using a ‘green’ copper(I)-catalyzed azide–alkyne cycloaddition procedure. Access to new bio-based chemicals and oligomeric materials via a click-chemistry approach is also demonstrated using this bio-derived building block.

Oxidative esterification of biomass-derived 5-(hydroxymethyl) furfural (HMF) and furfural and their derivatives has been performed using a simple MnO2/NaCN system. The developed method allows the selective one-pot transformation of HMF to dimethyl furan-2,5-dicarboxylate (FDME) in 83% isolated yield without the formation of a free acid. Simplification of FDME production provides the missing link for manufacturing sustainable value-added materials from biomass. Addition of water to the oxidative system allows finetuning of reaction selectivity to obtain the previously difficult-to-access pure methyl 5-(hydroxylmethyl) furan-2-carboxylate in one step directly from the unprotected HMF without chromatographic separation.

The study is devoted to search for organometallic complexes with considerable dipole moments suitable for the creation of new electret materials. The latter are formed by intercalation of organometallic molecules with a high dipole moment into a polymeric matrix. Titanyl and vanadyl complexes with etioporphyrin II were synthesized. The obtained compounds were identified with the use of electronic spectroscopy, NMR spectroscopy, mass spectrometry and liquid chromatography, and studied by vibrational spectroscopy and X-ray photoelectronic spectroscopy. Quantum chemical calculations for the optimization of the geometry of etioporphyrin II complexes with vanadyl and titanyl cations were performed. Their vibration spectra, dipole moments and distribution of charge and spin densities were calculated. Mulliken population analysis was carried out. It was shown that the “apix” bond between the metal in the vanadyl complex with etioporphyrin II is of more pronounced covalent nature. In contrast, in case of titanyl a structure with some redistribution of electron density onto the oxygen atom is implemented. This increases the polarity of the “apix” Ti-O bond and the dipole moment of the titanyl macrocomplex in general. The calculated dipole moment of the titanyl complex is higher (2.94 D) than that of the vanadyl complex (2.32 D)

Charge-discharge processes of supercapacitor with carbon black KJEC 600/Li in non-aqueous electrolyte: 1 M LiPF6 in a mixture of ethylene carbonate (1/3), diethyl carbonate (1/3), dimethyl carbonate (1/3) are investigated. Galvanostatic cycling was carried out in the range from 1 to 4 V with currents from 100 to 5000 mA/g of carbon black. The maximum discharge capacity of 196 F/g has been reached. The porous structure and hydrophilic-hydrophobic properties of carbon black KJEC 600 were investigated by the standard contact porosimetry method (MSCP). The following values were obtained: total specific surface area of 2500 m2/g, total porosity of 7.8 cm3/g, hydrophilic porosity of 4.9 cm3/g, hydrophobic porosity of 2.9 cm3/g. The obtained experimental dependence of the energy efficiency has a maximum (80%) at a current of 250 mA/g. Mathematical modeling of charge-discharge processes of the supercapacitor is developed with taking into account the charging of the double electric layer (EDL) and adsorption of lithium ions according to the Butler-Volmer equation and the Frumkin isotherm for the carbon electrode are taken into account. From the comparison of the calculated and measured charge-discharge curves it follows that these curves are satisfactorily consistent with each other, which indicates the correctness of the model. The density of the exchange current and the specific capacitance of the EDL refereed to the true surface found by the fitting are equal to i0,ad = 2.8 × 10−29A/сm2 and Cdl = 3.5 μF/сm2 respectively.

On the basis of the developed model for different specific currents the energy efficiency dependences on the exchange current density of the adsorption reaction were calculated. Interestingly, these dependencies have a minimum. Based on the model, the profiles of the potential the surface coverage of lithium ions were also calculated.

o-Ferrocenylcarbonylbenzoic acid (eta(5)-C5H5)Fe(eta(5)-C5H4C(O)C6H4COOH) (I) and o-cymantrenylcarbonylbenzoic acid (II) were obtained from ferrocene or (eta(5)-C5H5)Mn(CO)(3), respectively, by the Friedel-Crafts reaction with phthalic anhydride. Methyl o-ferrocenylcarbonylbenzoate (eta(5)-C5H5)Fe(eta(5)-C5H4C(O)C6H4COOMe (III) and methyl o-cymantrenylcarbonylbenzoate (CO)(3)Mn(eta(5)-C5H4C(O)C6H4COOMe) (IV) were synthesized from I and II, respectively using dimethyl carbonate (DMC) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to promote the methylation reaction. 4-Ferrocenylphthalazin-1(2H)-one (V) and 4-cymantrenylphthalazin-1(2H)-one (VI) were obtained by the interaction of hydrazine hydrate with I and II, respectively, by the prolonged reflux or convenient solvothermal synthesis. Cyclic voltammetry measurements showed that compounds III and V undergo reversible one-electron oxidation, localized presumably at the ferrocene unit. For III the irreversible one-electron oxidation is apparently associated with the oxidation of the benzoate fragment. All new compounds were characterized by spectroscopic methods and the molecular structures of II and III were determined by X-ray diffraction analysis.

o-Ferrocenylcarbonylbenzoic acid (eta(5)-C5H5)Fe(eta(5)-C5H4C(O)C6H4COOH) (I) and o-cymantrenylcarbonylbenzoic acid (II) were obtained from ferrocene or (eta(5)-C5H5)Mn(CO)(3), respectively, by the Friedel-Crafts reaction with phthalic anhydride. Methyl o-ferrocenylcarbonylbenzoate (eta(5)-C5H5)Fe(eta(5)-C5H4C(O)C6H4COOMe (III) and methyl o-cymantrenylcarbonylbenzoate (CO)(3)Mn(eta(5)-C5H4C(O)C6H4COOMe) (IV) were synthesized from I and II, respectively using dimethyl carbonate (DMC) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to promote the methylation reaction. 4-Ferrocenylphthalazin-1(2H)-one (V) and 4-cymantrenylphthalazin-1(2H)-one (VI) were obtained by the interaction of hydrazine hydrate with I and II, respectively, by the prolonged reflux or convenient solvothermal synthesis. Cyclic voltammetry measurements showed that compounds III and V undergo reversible one-electron oxidation, localized presumably at the ferrocene unit. For III the irreversible one-electron oxidation is apparently associated with the oxidation of the benzoate fragment. All new compounds were characterized by spectroscopic methods and the molecular structures of II and III were determined by X-ray diffraction analysis.

Single-phase Sr1– x – yYbxEuyF2+ x + y solid solutions with an average particle size near 90 nm have been synthesized via co-precipitation from aqueous solutions, followed by high-temperature annealing. Efficient Yb3+ luminescence was observed upon excitation at a wavelength of 266 nm. The highest external quantum yield of ytterbium luminescence (2.5%) under pumping at a wavelength of 266 nm was reached for the SrF2:Yb(1.0 mol %),Eu(0.05 mol %) composition.

Ytterbium-doped single crystals of the high-temperature hexagonal sodium sulphate modification are grown by the Czochralski method. It is found by energy dispersive analysis that the crystallization occurs congruently. The Yb :Na2SO4 crystals have additional (with respect to Yb 3+ ions) absorption bands in the regions of 650, 850 and 1150 nm, which obviously belong to colour centres. The luminescence spectrum of the Yb :Na2SO4 single crystal noticeably differs from the luminescence spectrum of Yb :YAG crystals by the presence of a broad band without a prominent peak. The luminescence decay curve for the powder is single-exponential with a time constant of 1175 ms, which is somewhat larger than that for the Yb :YAG crystal. The lifetime of the ytterbium excited state does not change during storage of the samples in air for a week.

The effect of mild pyrolysis methods (hydrothermal carbonization and torrefaction) on the physi-cochemical properties of biocoal was studied. It was established that biocoal obtained by hydrothermal car-bonization has a large specific surface area and exerts an exothermic effect upon decomposition; as comparedwith the samples obtained by torrefaction, it has a more dispersed structure and lower ash content.