E. G. Il’in

Uranyl complexes with acetophenone oxime

The interaction of uranyl compounds with acetophenone oxime has been studied. Mixed-ligand uranyl acetophenone oximates have been synthesized. X-ray crystallography shows that, in single crystals of [UO2(C8H8NO)2{(CH3)2SO}2] and [UO2(C8H8NO)(NO3){(CH3)2SO}2], acetophenone oxime is coordinated to uranyl as a bidentate chelating ligand.

X-ray photoelectron spectroscopic characterization of the acetylene cyclotrimerization catalyst NbCl2(CnHn) (n = 10–12)

The elemental and ionic compositions of the surface of NbCl2(CnHn) (n = 10–12), an active catalyst for acetylene cyclotrimerization into benzene, have been determined by X-ray photoelectron spectroscopy. Binding energy data for the sample sputtered with argon ions Eb(Nb3d5/2) = 203.8–204.2 eV) suggest that the oxidation state of niobium in the active catalyst is +2 or +3. The narrow C1s line indicates the equivalence of all carbon atoms, and the corresponding binding energy, Eb(C1s) = 284.0 eV, is close to the BE value for cyclic unsaturated hydrocarbons with conjugate double bonds. Interacting with atmospheric oxygen and moisture during sample preparation, niobium ions on the catalyst surface oxidize to their highest oxidation state, +5, characterized by Eb(Nb3d5/2) = 207.3–207.7 eV. These data suggest that niobium oxychlorides or oxides form ion the sample surface. The catalyst is stable in a high vacuum and undergoes slight charging under the action of an X-ray beam, showing poor dielectric properties.

X-ray photoelectron study of the MoCl2C30H30 composite

The surface of a MoCl2C30H30 composite in the form of molybdenum nanoclusters in a polyacetylene matrix, produced by reacting MoCl5 with C2H2 in benzene and toluene, has been studied by X-ray photoelectron spectroscopy before and after Ar+ ion milling. The composite actively reacts with atmospheric oxygen and moisture. As a result, the molybdenum clusters on its surface oxidize to molybdenum(V) or molybdenum(VI) oxides or oxychlorides (Eb(Mo 3d5/2) = 232.3–232.5 eV) during the sample preparation process. The electron binding energy of molybdenum affter surface etching (Eb(Mo 3d5/2) = 228.5 eV) suggests that the oxidation state of the molybdenum in the composite is 2+ or 3+. Analysis of the structure of the spectrum of the C 2s electrons of the inner valence molecular orbitals using the energy level diagram of the C2 molecule suggests that the hydrocarbon matrix of the composite contains, in addition to-CH=CH-CH=CH- conjugate bonds, linear carbyne fragments: -HC=C=CH- or -C≡C-. After etching, the surface layer of the composite contained argon, which might be due to adsorption because of the small particle size of the composite or chemisorption on the surface of the polyacetylene matrix. The composite is stable in a high vacuum of 1.3 × 10−5 Pa up to 350°C and does not experience charging when exposed to X-rays, which indicates that it has weak dielectric properties.

Uranyl aquahydroxylaminate complexes

Uranylaqua complexes with N-methyl-, N-ethyl-, N-isopropyl-, and N,N-dimethylhydroxylamines were studied. The structure of [UO2{(CH3)2NO}2(H2O)2] was determined by X-ray crystallography. The N, N -dimethylhydroxylaminate ion is coordinated to uranyl through the nitrogen and oxygen atoms with the formation of a three-membered chelate ring.

Molybdenum(VI) complexes with N-substituted hydroxylamines

New molybdenum(VI) complexes with N-monoalkylsubstituted hydroxylamines have been synthesized and studied. The structure of [MoO2(C2H5NHO)2] and [MoO2(i-C3H7NHO)2], whose distinguishing feature is the bidentate chelate coordination of the ligand to molybdenum with the formation of the three-membered NMoO chelate ring, has been determined by X-ray diffraction.

Extraction of antimony and tantalum from aqueous fluoride solutions by n-octanol and tributyl phosphate

Abstract19F and 21Sb NMR spectroscopy and chemical analysis were used to study the composition and structure of fluoride complexes of antimony(V) and tantalum(V) in organic and aqueous phases in extraction by tributyl phosphate (TBP) and n-octanol. It is found that extraction from solutions containing a single element or both elements occurs via the hydrate-solvate mechanism. The possibility of separating tantalum(V) and antimony(V) by extraction from fluoride solutions is shown. The efficiency of tantalum(V) and antimony(V) separation by extraction from fluoride solutions is enhanced at a transition from TBP to n-octanol.

Uranyl complexes with ethylmethylglyoxime

Uranyl complexes with ethylmethylglyoxime were studied. The structure of (CN3H6)4[(UO2)2(CO3)(C2O4)2(C5H8N2O2)] · 1.5H2O was determined by X-ray crystallography. The structure of the complex is binuclear with a double carbonate dioximate bridging fragment.

Synthesis and speciation of zirconium tetrafluoride complexes with phosphoryl-containing bases Ph3PO, Bu3PO and (Me2N)3PO in solutions

Zirconium fluoro complexes with phosphoryl-containing bases (L) have been synthesized by the reaction of a suspension of ZrF4(dmso)2 in toluene with an excess of Ph3PO or Bu3PO, as well as (Me2N)3PO in CH2Cl2. The composition and structure of the complexes in CH2Cl2 solutions have been studied by 19F NMR in the temperature range 293–203 K. Phosphine oxides are substituted for dmso to form mainly cis-tetrafluoro species, insignificant amounts of trans-tetrafluoro species, and mer- and fac-[ZrF3L3]+ complexes. In addition to these species, the reaction with Bu3PO yields the dimeric oxo complex (µ-O)[ZrF3(Bu3PO)2]2. Hydrolysis of fluoro complexes in CH2Cl2 with the use of an NBu4OH solution in iso-PrOH does not lead to oxo and hydroxo complexes: first, the [ZrF5L]– complex is formed, and the final hydrolysis product is ZrF62-. The fine structure of 19F NMR resonance lines for the zirconium fluoride compounds [ZrF5L]–, cis- [ZrF4L2], dimeric oxo complex, and mer-[ZrF3L3]+ in organic solvents has been observed for the first time, which makes it possible to reliably identify the composition and structure of the zirconium coordination polyhedron in the complexes under consideration.

Thermal stability and products of decomposition of molybdenum(IV) complex with isopropylhydroxylamine [MoO2(i-C3H7NHO)2]

The thermal behavior of the molybdenum(VI) complex with N-isopropylhydroxylamine [MoO2(i-C3H7NHO)2] has been studied. The thermal decomposition of the complex has been found to proceed in a single stage at 185.5°C and to result in non-stoichiometric molybdenum(IV) dioxide.

Specifics of titanium tetrafluoride complexation with Ph2P(O)(CH2)2C(O)NMe2: The remarkable stability of the seven-membered chelate heterocycle TiOPCCCO and its conformational isomerism in solution

The composition and structure of the products of the reaction of titanium tetrafluoride with Ph2P(O)(CH2)2C(O)NМе2 (L), the simplest representative of diphenyl[2-(N,N-dialkylcarbamoyl)ethyl]phosphine oxides, in a СН2Сl2 have been studied by 19F and 31P NMR. It has been shown for the first time that functionalized phosphine oxides form stable seven-membered chelate heterocycles on complexes of d° transition metals. On the basis of NMR data, previously unknown conformational isomerism of the seven-membered TiOPCCCO heterocycle in solution has been proposed. A simple and rather efficient method of synthesis of the ligand (L) from commercially available reagents has been developed.