The reaction of ZrCl4 or HfCl4 with excess 2-methylpropanoic acid when boiling under reflux has been studied. The formation of polynuclear Zr and Hf complexes of the composition M2O(i-C3H7CO2)6 during prolonged reflux of the reaction mixtures was found. The complexes are very sensitive to hydrolysis, forming hexanuclear [M6(O)4(OH)4(i-C3H7CO2)12]. The reactions have a general character for aliphatic acids and can be used as an alternative to the known methods for the synthesis of polynuclear carboxylate clusters of Group 4 metals. The crystal and molecular structures of previously undescribed {[Hf6(μ3-O)4(μ3-OH)4(i-C3H7CO2)12(H2O)]·3i-C3H7COOH} have been determined. The molecular structure is a completely asymmetric hexanuclear cluster containing six Hf(IV) atoms united by a 4:4 μ3-O/OH system of bridges, and stabilized by twelve 2-methylpropanoate ligands, eight of which are bidentate bridging, three are chelating, and one is monodentate. The crystal structure of the complex includes three independent solvating 2-methylpropanoic acid molecules. The obtained IR spectroscopy data make it possible to determine the type of complexes in the reaction mixture. The results of the study may be useful for improving the catalytic systems for ethylene oligomerization.

The crystal and molecular structure of a polynuclear pivalate complex obtained by the interaction of ZrCl4 with pivalic acid is determined by X-ray diffraction analysis. The compound C71H124O28Zr4 crystallizes in a monoclinic crystal system. The crystal structure is refined in the nonstandard space group I2. The asymmetric part of the structure includes three Zr atoms, six pivalate ligands, and a bridging µ3-O oxygen atom, as well as disordered crystallization molecules of pivalic acid with an occupancy of 50

A new mechanically stimulated solid-state reaction of PtCl4 with sodium β-diketonates has been discovered. Platinum (II) β-diketonates were obtained by grinding excess sodium trifluoroacetylacetonate Na(tfac) or hexafluoroacetylacetonate Na(hfac) in a vibration ball mill, followed by subsequent heating of the resulting mixture. The reactions occur under much milder conditions (at about 170 °C) compared to similar reactions of PtCl2 or K2PtCl6 (at about 240 °C). Excess diketonate salt plays the role of a reducing agent in the conversion of Pt (IV) salt to Pt (II) compounds. The effect of grinding on properties of the ground mixtures was studied by XRD, IR, and thermal analysis methods. The difference in the course of the interaction of PtCl4 with Na(hfac) or Na(tfac) indicates the dependence of the reaction on the ligand properties. The probable reaction mechanisms were discussed. This method of synthesis of platinum (II) β-diketonates makes it possible to substantially reduce the variety of reagents used, the number of reaction steps, the reaction time, the use of solvents, and waste generation compared to conventional solution-based methods.

The mechanical activation (vibration ball milling) of solid starting reactants (mixtures of platinum group metal chlorides with sodium or potassium beta-diketonates) followed by heating results in the formation of the corresponding platinum group metal beta-diketonates. Simple (PdCl2, PtCl2), complex (K2PtCl6), and hydrated metal chlorides (RuCl3 center dot xH(2)O, RhCl3 center dot xH(2)O) can be used in the reaction. The considered method is quite general and enables to obtain various platinum group metal beta-diketonates with a conversion of up to similar to 85% directly from their chlorides by using the same process, varying only the duration of milling, milled mixture heating temperature and the product isolation method (sublimation or extraction).

Solid-phase reaction of copper(I) chloride with sodium β-diketonates under mechanical activation in a vibration ball mill involves disproportionation of CuCl with the formation of the corresponding copper(II) β-diketonate and highly reactive X-ray amorphous metallic copper nanoparticles. The effect of reaction conditions on the process and some properties of the activated mixtures have been studied.

The reaction of ZrCl4 with 2,2-dimethylbutanoic acid in excess of the acid and also in o-xylene at boiling point of the solvent was studied. Formed zirconium tetrakis(2,2-dimethylbutanoate) is volatile in vacuum that allows its using as a precursor for the preparation of inorganic materials by chemical vapor deposition. During the reaction Zr(C6H11O2)4 is condensed to form polynuclear complexes.

The effect of the mechanical treatment conditions and of the nature of reactants on the course of the solid-phase reaction of vanadium(III) chloride with sodium β-diketonates and potassium tetramethylheptanedionate, on the yield of the reaction products, and on some properties of the activated mixtures was examined. A method was developed for the synthesis of vanadium(III) β-diketonates by the solid-phase mechanochemical reaction of vanadium(III) chloride with appropriate sodium or potassium β-diketonate, followed by sublimation or extraction.

The structure and thermal properties of nanocomposites based on copper nanoparticles in a polyethylene matrix that are obtained by mixing a precursor in the melt have been investigated. Structural changes of nanocomposites depending on the content of copper nanoparticles and properties of a polymer matrix have been identified.

A new method for preparation of zirconium and hafnium phenoxyimine complexes L 2 MCl 2 (L is N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroanilinate anion, M = Zr, Hf) by the solid state interaction of N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroaniline, the corresponding metal chlorides, and sodium hydride under mechanical activation followed by heating of the activated mixture was developed. The obtained complexes have a high catalytic activity in the reaction of ethylene polymerization.

A possibility of application of mechanochemical method for the synthesis of triphenylmethylium and triphenylcyclopropenylium tetrakis(pentafluorophenyl)borates by the solvent-free reaction of solid starting compounds was studied. Some specific features of these reactions were discovered. Preparative methods for the mechanochemical synthesis of these salts were developed. This method makes the process shorter and excludes the use of solvents in the synthesis.

It has been shown that 8-quinolinolate zirconium complexes ZrOx nCl 4-n can be synthesized by the mechanochemical method using zirconium tetrachloride and sodium quinolinolate as starting materials. The ZrOx nCl 4-n – Et 1.5AlCl 1.5 system exhibits a moderate catalytic activity and high selectivity in ethylene oligomerization. The system activity increases symbatically with the number of chelating ligands in the zirconium precursor. The ZrOx nCl 4-n polymethylalumoxane system exhibits a negligible catalytic activity in ethylene polymerization. An explanation of the phenomena observed is proposed.

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.

The transformations of bis[N-(3,5-di-tert-butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]-titanium(iv) dichloride (L2TiCl2) occurring in toluene under the action of methylalumoxane (MAO) were studied by 1H NMR spectroscopy. The commercially available MAO containing trimethylaluminum (AlMe3) and MAO free of AlMe3 (the so called “dry” MAO) were used. The catalytic transformations of hex-1-ene involving the systems L2TiCl2-MAO were studied. We proposed the structures of the cationic titanium complexes formed in the absence and in the presence of hex-1-ene under the action of MAO. In the absence of olefin, neutral and cationic titanium complexes are decomposed under the action of AlMe3 according to the exchange reaction of the complex ligand with the methyl groups of AlMe3 to form LAlMe2. The neutral complexes react considerably faster than the cationic ones. In the presence of olefin, decomposition of complexes under the action of AlMe3 is suppressed. The titanium complex activated by “dry” MAO isomerizes hex-1-ene to hex-2-ene. In the presence of large amounts of TMA (commercial MAO), this reaction does not take place.

Reactions of zirconium tetrachloride with pivalic acid in benzene, toluene, m- and o-xylene, and in excess pivalic acid at the boiling temperature of a solvent were studied. The product of reactions in aromatic solvents was found to have the composition corresponding to the formula Zr(2)O(Piv)(6). The reaction in excess pivalic acid resulted in the formation of the compound Zr(Piv)(4). The reaction products were investigated by X-ray powder diffraction, IR and NMR spectroscopy, and their physicochemical properties were compared with those of zirconium tetrapivalate synthesized by a mechanically activated solid-phase reaction between ZrCl(4) and sodium pivalate.

We demonstrate that nanocomposites (metals and metal carbides and sulfides) can be produced by thermolysis (370 and 600°C) in a self-generated atmosphere using Cu(II), Co(II), and Ni(II) 2-hydroxy- and 2-N-tosylaminobenzaldehyde azomethine bis-chelates as precursors.

Показано, что нанокомпозиты (металлы, их карбиды и сульфиды) могут быть получены в условиях термолиза (370 и 600°С) в самогенерирующей атмосфере при использовании в качестве прекурсоров бисхелатов азометинов 2-гидрокси- и 2-N-тозиламинобензальдегидов Cu(II), Co(II) и Ni(II).

Catalytic properties of the phenoxyimine zirconium complexes, viz. , bis[ N -(3,5-di- tert -butylsalicylidene)anilinato]zirconium(IV) dichloride ( 1 ) and its fluorinated analog, bis[ N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]zirconium(IV) dichloride ( 2 ), were studied. Ethylene homopolymerization and copolymerization of ethylene with α-olefins were chosen as catalytic reactions, and various organoaluminum compounds served as activators: commercial polymethylalumoxane (MAO) containing ∼35 mol.% of trimethylaluminum (TMA), MAO purified from TMA (“dry” MAO), and “classical” organoaluminum compounds, namely, TMA and triisobutylaluminum (TIBA). Complex 1 is not activated by “dry” MAO but is efficiently transformed into the catalytically active state by commercial MAO, “conventional” TMA, and TIBA. These processes give low-molecular-weight polyethylenes (PE) characterized by high values of polydispersity indices and by polymodal curves of gel permeation chromatography (GPC). The order of decreasing the efficiency of activation for the cocatalysts is MAO > TIBA > TMA. Fluorinated complex 2 exhibits a high activity after its treatment with MAO and “dry” MAO, the activity is much lower upon mixing with TIBA, and complex 2 is inactive when using TMA. In the copolymerization of ethylene with hex-1-ene and dec-1-ene, complex 1 treated with MAO is highly active but gives a low level of insertion of the comonomer (1–2 mol.% in the copolymer). Complex 2 activated with “dry” MAO is more efficient in the copolymerization of ethylene with propylene or hex-1-ene but, like complex 1 , it does not produce copolymers with a high content of the comonomer. The both catalysts provide the insertion of α-olefin as isolated units separated by extended sections of the chain consisting of ethylene units.