A new one-pot synthesis method of dimethyl hexane-1,6-diyldicarbamate (HDC), a potential intermediate compound in the synthesis of polyurethanes, from CO2, methanol, and 1,6-hexanediamine (HDA) is disclosed. The starting materials are renewable, stable, easily available, and cheap. The process was implemented in 1-methyl-2-pyrrolidinone (NMP) solvent over CeO2 catalysts. Three different CeO2 catalysts (commercial nanospheres, CeO2(c) obtained by direct calcination of (NH4)2Ce(NO3)6, and CeO2 nanorods) were tested in this reaction and their micromorphology and physical–chemical properties were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and N2 adsorption. CeO2 nanorods proved to be the most active catalytic material. The influence of different parameters on reaction outcome was studied. The yield of HDC was about 80% under optimized reaction conditions. Experiments for better understanding of reaction mechanism were also performed.

Conversion of carbon dioxide into useful chemicals is a valuable task. One way to perform it is to transform CO2 into dimethyl carbonate (DMC) by a reaction with methanol. Catalyst exerts significant impact on this process. During this work, Cu-Ni@VSiO bimetallic catalysts were successfully synthesized by traditional solution and novel sulfuration methods. The catalytic materials were characterized by several analytical techniques and were tested in a continuous fixed-bed reactor under different reaction conditions to promote DMC synthesis from CO2 and methanol in the absence of dehydrating agents. The effects of reaction temperature, pressure, space velocity, metal loading, and bulk density on the catalytic performance were investigated in detail. It was found that the activity of Cu-Ni@VSiO catalyst with the support obtained by the novel sulfuration method is about three times higher when compared to that of the catalyst with the support that is synthesized by the traditional solution method. This result may stem from the difference in microstructure of the studied catalytic materials.

Based on the analysis of scientific and patent literature published over the period from June, 2010 to February, 2016, data on catalytic metal complex systems on the basis of chromium with various degrees of oxidation in the reaction of selective tri- and/or tetramerization of ethylene have been systematized and described. Key information about catalytic systems exhibiting high selectivity for higher alpha-olefins (1-hexene and 1-octene) or their mixtures is surveyed.

The objective of this review is the analysis and comment of recent publication results (from July 2010 until February 2017) obtained for selective ethylene oligomerization toward 1-hexene and 1-octene catalyzed by chromium-based catalytic systems. Both the scientific and patent literature was taken into the consideration. The catalytic systems for ethylene oligomerization are classified on the basis of the ligand type employed. The activities and selectivities of the catalysts are provided throughout the text. Despite a big success in the field, there is still rather limited choice of catalysts affording simultaneously high activity, selectivity and low polymer proportion. This is especially true for ethylene to 1-octene tetramerization reaction. The results of the studies concerning oligomerization mechanisms obtained over the recent years are also included in this review.

The cooligomerization of CO with cyclic olefins, such as norbornene, 5-vinyl-2-norbornene, and dicyclopentadiene, in toluene in the presence of supported palladium catalysts containing 2,2'-bipyridine as a ligand is studied. It is shown that, during copolymerization, opening of the double bond in a ring occurs, while in the case of 5-vinyl-2-norbornene, vinyl bond C=C is not involved in the reaction. When ethylene is added to the reaction mixture, it does not participate in polymer-chain growth. The yield of the process is commensurable with the yield attained in the case of a homogeneous catalytic system, and the conversion of olefins is as high as 47%. The copolymers in the solid state occur in the form of spiroketal structures that, during dissolution, transform into ketone structures to different extents.

Thermal properties and the deformational behavior of ternary alternating copolymers of carbon monoxide with ethylene and other olefins (propylene, 1-butene, styrene) with molecular masses of M n = 1000–35000 and molar fraction of the third comonomer in the polymer chain from 0.02 to 0.70 were investigated. Temperatures of melting and glass transition are significantly affected by the composition of the products. Varying the nature of the third comonomer or the content of its units in the polymer chain and the molecular masses of terpolymers makes it possible to obtain materials with Young’s moduli of 0.003–3.090 GPa and elongations at break of 5–2000%.

В работе изучены некоторые термические и деформационные свойства тройных чередующихся сополимеров монооксида углерода с этиленом и другими олефинами (пропилен, бутен-1, стирол) с молекулярной массой Mn = 1000–35 000 и мольной долей третьего сомономера в полимерной цепи от 0.02 до 0.70. Значительное влияние на температуру плавления и стеклования оказывает состав продуктов. Варьирование природы третьего сомономера или содержания звеньев третьего мономера в полимерной цепи, а также молекулярной массы терполимеров позволило получить материалы с модулем Юнга 0.003–3.090 ГПа и относительным удлинением при деформации 5–2000%.

A method was developed for synthesis of chromium(III) tris(2-ethylhexanoate) by the mechanochemical interaction of chromium(III) chloride with sodium 2-ethylhexanoate without a solvent, followed by heating of the reaction mixture. The influence exerted by the conditions of the mechanical activation and the subsequent thermal treatment on the course of the processes and some properties of activated mixtures was studied. Chromium(III) tris(2-ethylhexanoate) can be isolated from the reaction mixture in a ∼75% yield. Both the activated reaction mixture and the target product obtained exhibit a high catalytic activity and selectivity in the reaction of ethylene trimerization.

Изучена соолигомеризация СО с циклическими олефинами: норборненом, 5-винил-2-норборненом и дициклопентадиеном в присутствии нанесенных палладиевых катализаторов с 2,2-бипиридином в качестве лиганда в среде толуола. Показано, что в процессе сополимеризации происходит раскрытие двойной связи в цикле, а в случае 5-винил-2-норборнена винильная связь С=С не вступает в реакцию. Кроме того, при добавлении в реакционную смесь этилена не наблюдалось его участия в росте полимерной цепи. Процесс протекает с выходом, сравнимым с выходом на гомогенных каталитических системах, а конверсия олефинов достигает 47%. Сополимеры в твердом состоянии находятся в виде спирокетальных структур, которые при растворении в различной степени переходят в кетонные структуры.

Terpolymers of carbon monoxide with ethylene and styrene are synthesized in the presence of supported palladium catalyst in toluene and heptane medium for the first time. The terpolymerization rate exceeds the rate of carbon monoxide and ethylene copolymerization. The maximum terpolymer yield amounts 7.9 g per g of supported catalyst per hour or 321 g per g of palladium per hour. The influence of reaction temperature, pressure, 1.4-benzoquinone amount and co-monomers mole ratio on the yield and the composition of terpolymer have been studied. The NMR 13 C data obtained testify to a distribution of ethylene and styrene units in terpolymer with the predominance of short blocks at equal contents of comonomer units.

Carbon monoxide terpolymers with ethylene and propylene are synthesized in the presence of a supported palladium complex in toluene for the first time. The reaction rate calculated from the terpolymer yield per gram of supported catalyst per hour depends on the reaction temperature and the propylene-to-ethylene molar ratio in the reaction solution. The amount of terpolymer per mole of palladium formed per hour decreases as the molecular mass of the terpolymer increases. Terpolymers with a molar fraction of propylene units up to 0.72 are synthesized when the initial propylene-to-ethylene molar ratio in the reaction solution is increased to 15.3. The number-average molecular mass of the terpolymer decreases from 30650 to 1420 when the temperature of synthesis is increased from 40 to 90°C.

The kinetics of the alternating copolymerization of ethylene with carbon monoxide has been studied in the presence of a palladium catalyst immolized on a polymer support in various media (methanol, toluene, heptane). In the case of hydrocarbon solvents, the activity of the supported catalyst is commensurable with the activity of a homogeneous system in methanol. The melting temperature of the resulting copolymer and its molecular mass depend on the solvent nature. The IR reflectance spectra of the active palladium complex and the ethylene-carbon monoxide copolymer are measured.