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A thermodynamic analysis of the experimental conditions of the Beckmann rearrangement reaction of oximes into amides has been undertaken to examine whether the reaction is under thermodynamic or kinetic control. To answer this question, the thermodynamic properties of the typical Beckmann rearrangement reactions in the ideal gaseous state—cyclohexanone oxime to caprolactam and 2-butanone oxime to N-methyl-propanamide—were studied by using the quantum mechanical method. Gibbs energy and equilibrium constants of the Beckmann rearrangement have been assessed in the gaseous and the liquid phases. Results of the thermodynamic analysis have shown that Beckmann rearrangements are kinetically controlled. Thus, a search for possible active ionic liquid based catalysts for the mild reaction conditions has been performed.

The chemical equilibrium of mutual interconversions of tert-amylbenzenes was studied in the temperature range 286-423 K using chloroaluminate ionic liquids as a catalyst. Enthalpies of isomerization and transalkylation of tert-amylbenzene were obtained from temperature dependences of the corresponding equilibrium constants in the liquid phase. The molar enthalpy of formation of tert-amylbenzene was measured using combustion calorimetry and was also obtained by the transpiration method. Using these experimental results, high-level ab initio methods (B3LYP and G3MP2) have been successfully tested for the prediction of reaction enthalpies for the four reactions under study. New experimental results have been used to derive a strain of tert-amylbenzene, which is useful in any additive scheme as the non-nearest-neighbor interaction which is specific for the branched alkylbenzenes.

This work has been undertaken to obtain new thermochemical data for ethanediol and propanetriol acetates and to improve the group contribution methodology for the prediction of the thermodynamic properties of compounds relevant to biodiesel. Standard molar enthalpies of formation in the gaseous state of a series of 1,2-ethanediol monoacetate, 1,2-ethanediol diacetate, and 1,2,3-propanetriol triacetate have been obtained from combustion calorimetry and results from the temperature dependence of the vapor pressure measured by the transpiration method. To verify the experimental data, ab initio calculations of all compounds have been performed. Enthalpies of formation derived from the Gaussian 03 second-order Moller−Plesset (G3MP2) method are in good agreement with the experimental results. The strength of the hydrogen bond in 1,2-ethanediol monoacetate and in 1,2-ethanediol have been obtained using ab initio calculations and the group additivity method.

The standard molar enthalpies of formation of ethylene carbonate, propylene carbonate, and butylene carbonate were measured using combustion calorimetry. Ab initio calculations of molar enthalpies of formation of alkylene carbonates were performed using the G3MP2 method. The calculated values are in excellent agreement with available experimental data. Ring strain corrections were quantified for the refinement of the group-contribution method for prediction of enthalpies of formation and vaporization of alkylene carbonates.

Standard molar enthalpies of formation in the gaseous state of a series of alkyl 3-methylbut-2-enoates have been obtained from combustion calorimetry and results from the temperature dependence of the vapor pressure measured by the transpiration method. To verify the experimental data, we have performed ab initio calculations of all compounds. Enthalpies of formation derived from the G3MP2 method are in excellent agreement with the experimental results. Quantitative analysis of strain effects in alkyl 3-methylbut-2-enoates was discussed in terms of deviations of deltafH degrees m(g) from the group additivity rules. Energetics of the cis-trans isomerization of carboxylic acid derivatives was studied using G3MP2 and DFT methods. Values of strain and cis-trans corrections derived in this work provide further improvement on the group-contribution methodology for prediction of the thermodynamic properties of compounds relevant to biodiesel.

New amidine-containing polymers were prepared by the polycondensation of aromatic diamines with bis(imidoyl) chlorides in polar organic solvents in the presence of various catalysts (triethylamine, tributylamine, and pyridine N-oxide). Optimal synthesis conditions, namely, temperature, duration, concentration of monomers and catalyst, and the order of reagent loading, were established. The structure of polyamidines was studied by elemental analysis and IR and NMR spectroscopy. When the polymers were heated to 250°C in vacuum, their molecular masses increased.