Home – Home – Jornals – Avtometriya 2017 number 1

A simplified method of plane trajectory calculation is proposed for solving the problem of planning the path defined by a sequence of turning points. The trajectory consists of oriented segments of straight lines joined by clothoids (Cornu spirals). The efficiency of the method is validated by means of numerical simulations in the MATLAB/Simulink environment.

Various aspects of mathematical modeling of the inclination parameter converter based on two double-axis accelerometers in a single integrated design are considered. Possible variants of design patterns of such a converter are presented. Additional turns of the accelerometer sensors mounted in the transducer body are considered. Generalized static mathematical models for two double-axis accelerometers as part of the inclination parameter converter are obtained, which ensure accurate determination of the spatial orientation angles of an object: zenith and sighting (apsidal) angles.

An automated system of acquisition of raw experimental data and a control system for operation modes of an experimental large-scale separation column are described. The influence of a new method of refluxing of structured packing on the separation column efficiency is studied. Based on the data obtained by the developed automated system, a 20-30 % increase in the efficiency of mixture separation on structured packing is expected.

A problem of control of quadcopters in a leader-follower group is considered. A method is proposed, which allows control actions for the follower robot to be formed only on the basis of information about the follower motion parameters and the relative positions of the leader and follower.

The efficiency of methods of the spectral-spatial classification of difficult-to-distinguish types of vegetation on the basis of hyperspectral data of remote sensing of the Earth, which take into account local neighborhoods of analyzed image pixels, is experimentally studied. Algorithms that involve spatial pre-processing of the raw data and post-processing of map charts of pixel-by-pixel spectral classification are considered. Results obtained both for a large-scale hyperspectral image and for its test fragment with different methods of learning sample formation are reported. The classification accuracy in all cases is estimated through comparisons of sub-satellite data and map charts of classes formed by using the compared methods. The reasons for the differences in these estimates are discussed.

This paper presents a method for determining the spatial coordinates of a moving radiation source on the basis of a two-position system from measurements of one bearing and relative energy measurements of the received signal taking into account the effect of its reflection from the Earth surface.пThe passive location problem is solved for low elevation angles taking into account the curvature of the Earth and using a polynomial model of source motion. An algorithm is developed for the parametric identification of this model based on a sample of measurements of increasing size in a regularized formulation, and the accuracy characteristics of the method are analyzed.

Catalytic heater model in the form of a tubular reactor, in the tube space of which heat is removed using a high-boiling coolant was elaborated. Kinetic parameters of methane oxidation rate constant on a manganese-alumina catalyst (pre-exponential factor and activation energy) that were used to calculate the observable reaction rates on grains of various shapes and sizes were determined. It was demonstrated that the maximum specific heat power of a catalytic heater is 19.25 kW/m³; it can be obtained by applying the catalyst in the form of rings with dimensions of 5 × 5 × 2 mm, under the following conditions: inlet methane concentration of 3 %, inlet temperature of 500 °C, coolant temperature of 400 °C, tube length of 1 m, tube diameter of 8 cm, linear rate of 0.05 m/s. With such parameters, the degree of methane conversion is greater than 98 %, and the maximum temperature does not exceed 770 °C, which meets accepted limitations.

The effect of the reduction period in hydrogen of Pd/Sibunit and Pd-M/Sibunit (M: Ga, Zn, Ag) catalyst, as well as the nature of palladium and zinc precursors on properties of samples in the of liquid-phase hydrogenation reaction of acetylene into ethylene was investigated. It was found that the introduction of the second metal (Ga, Zn, and Ag) into the Pd-catalyst prevented sintering of the active component during reductive thermal treatment resulting in the reduction period does not affect the activity and selectivity of the modified catalysts, unlike an unmodified Pd/Sibunit sample. For the Pd-Zn/Sibunit sample, it was demonstrated that modification with zinc led to a change in the nature of catalytic active sites and an increase in their number, regardless the nature of metal precursors; herewith, the Pd-Zn/Sibunit system synthesized from solutions of palladium nitrate and zinc nitrate is distinguished by a higher activity and selectivity.

A 0.25 % Pt/γ-Al₂O₃ catalyst was investigated. The sample was tested in modelling of joint conversion of butane and hexane, propane, and heptane with assessing kinetic parameters of the reactions under study. It was found that a decrease in the activation energy by 10.6 kJ/mol and an increase in the rate constant of aromatization by 1.3 times in comparison with hexane conversion was observed at joint conversion of butane and hexane, which leads to an increase in the yield of aromatic hydrocarbons. At the introduction of propane into the reaction medium to heptane, a reverse dependence was detected.

The present work is devoted to comparative analysis of the activity and stability of low-percentage palladium catalysts under conditions of three-route catalysis (CO and hydrocarbons oxidation, and nitrogen oxides reduction). Gamma alumina and delta alumina were used as carriers. Catalysts containing 0.12 % Pd and δ-Al₂O₃ on γ-Al₂O₃ and δ-Al₂O₃ were prepared by the wetness impregnation method. The resulting samples were studied by a set of physicochemical method. The forced thermal ageing method was used to assess the stability of catalysts to deactivation processes of the active component of Pd. Ethane hydrogenolysis allowed assessing the dispersion degree of the active component. The highly sensitive methods of electron spin resonance (ESR) and electron spectroscopy of diffuse reflectance (ESDR) were used to study the state of deposited palladium. Testing of the catalytic activity of samples under conditions of three-route catalysis was carried out. As a result, it was demonstrated that phase conversions of an alumina carrier did not exert significant effects on the thermal stability of samples during catalytic reactions.

An alternative method of joint disposal of acid tars (high-sulphur petrochemical waste) with wood-chemical industry and agriculture wastes, at which additional neutralization or trapping of sulphur acid decomposition products is not required, was investigated. At thermal treatment of a mixture of acid tar (a mixture of sulphuric acid and heavy oil fractions), template (high-ash biomass) and binder (furfurol, formaldehyde or resorcinol), sulphated carbon materials applicable as catalysts for a broad range of acid-catalyzed processes were obtained. The impact of synthetic methods for materials on acid and textural characteristics of materials was explored using BET, TGA, XPA, XPS methods and IR spectroscopy. Optimal conditions for the preparation of carbon materials with developed specific surface (up to 168 m²/g) and a high concentration of sulpho groups (up to 4.55 mass % SO₃H) were found. The addition of a template allows increasing calcination temperature (from 225 to 275 ^oC) that is required to achieve high specific surfaces, without a decrease in acidities (sulpho groups concentration) final samples. Testing of catalytic properties of the carbon materials obtained in modelling of a catalytic process for esterification of enanthic acid with methanol was performed.

The composition of sulphur compounds of oils in high-sulphur natural bitumen of the Ashalchi deposit (Russia), as well as its thermal cracking products was studied under various conditions. It was demonstrated that depending on thermal treatment conditions gas and coke formation, the composition of the liquid cracking products and sulphur content in them significantly changed. Cracking of bitumen in a reactor autoclave leads to an insignificant decrease in the content of benzothiophene homologs in the composition of oils, the products are enriched with of dibenzothiophene derivatives. Cracking of bitumen in a flow reactor allows decreasing the content of benzothiophene homologs by 37 %, and dibenzothiophene homologs - by 72 rel. % in liquid cracking products.

Analysis of the evolution of carbon black grades manufactured in Russia was given on the example of the Russia largest enterprise that is Omsk Carbon Group. Development trends innovative technologies of the enterprise in expanding varieties of carbon black grades were demonstrated. Innovative products including those manufactured under the brand OMCARB for various designations were presented in detail. Some results of scientific research carried out by the Scientific and Technological Center of Carbon Materials and Institute of Hydrocarbon Processing (IHP SB RAS) in the development trends of carbon black types were presented. Recommendations on rational choice and use of innovative varieties of black carbon were proposed in the first place to tire and industrial rubber goods, as well to as other polymer products manufacturers.

To improve biospecific properties of carbon enterosorbents for purposes of veterinary medicine methods of chemical modification of their surface were proposed. The first area is modification of carbon surfaces by the method of polycondensation of biologically active substances (arginine) and in situ formation of polymers (directly on the surface of carbon sorbents). Another method is impregnating into a porous matrix of carbon carrier nanodispersed betuline in a water soluble form. To study physicochemical characteristics of veterinary preparations synthesized the following methods were used: scanning electron microscopy (SEM) (relief and morphology); X-Ray phase analysis (phase composition); the method of low-temperature nitrogen adsorption-desorption (texture studies); X-Ray microanalysis and CHNOS Elemental Analysis (elemental composition): IR spectroscopic analysis, Kjeldahl method, H. P. Boehm's method and X-ray photoelectron spectroscopy (XPS) (surface functional composition of the synthesized samples). The article presents the study results of physicochemical properties of carbon sorbents before and after modification, which confirm the presence of polyarginine and betuline in the composition of the resulting samples.

To improve biospecific properties of carbon enterosorbents for veterinary purposes methods for chemical modification of their surface were proposed. Modified samples of carbon sorbent were synthesized: carbon sorbent containing polyarginine and the betuline preparation impregnated into a porous matrix. Adsorption properties of the tested samples in relation to substances modelling low and average molecular mass toxins (Vitamin В12, methylene blue) were studied. The assessment of adsorption properties in relation to proinflammatory cytokines at the example of a sorbent modified with polyarginine was carried out. It was found that adsorption properties of carbon sorbents were influenced by localized application of modifiers to carbon sorbent samples and elevated contents of oxygen- and nitrogen-containing groups on their surface.

Positive and negative effects of non–additivity of oxygen absorption rates at oxidation of Na₂S in the presence (Ni^II + Co^II)–containing catalysts were detected. It was determined that these effects were associated with peculiarities of the formation of nickel and cobalt sulphides particles. Positive effects of non–additivity were observed in the beginning of the reaction at the stage of forming metals sulphides embryos and referred to synergistic phenomena. Negative effects were detected at the growth stage of the sulphide phase particles. They are of nonsynergistic nature and associated with deposition of nickel sulphides on the surface of cobalt sulphide particles.

The effect of the catalytic addition of mesoporous aluminosilicate on the composition of the cracking products of natural bitumen on the Ashalchi deposit with a content of IBP-200 °C fractions of 4.6 mass % in the autoclave reactor was studied. It was demonstrated that the addition of 5 % catalyst increased destruction of resins and the yield of low-boiling fractions. It was determined that the catalyst modification with nanoscale nickel powder slowed down coke formation. At cracking of bitumen employing mesoporous aluminosilicate modified with nickel, the yield of IBP-360 °C fractions per 35.2 mass % was increased, and destruction of resins and asphaltenes was 48 % in comparison with the initial bitumen.

Homogeneous nitrogen doped (N-CNTs) bamboo-like carbon nanotubes with the carbon content up to 7.3 at % were obtained by catalytic decomposition of ordinary ethylene/ammonia mixture. Physicochemical properties of N-CNTs were studied by X-ray analysis, X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy methods. The effect of the synthesis temperature, catalyst nature and reaction mixture composition per the amount of nitrogen, ratio of its forms, defectiveness and morphology of N-CNTs was determined.

The study of concentration hysteresis in methane oxidation over alumoplatinum catalysts was conducted. It was determined that catalysts activation was accompanied by partial platinum reduction, the boundaries of existence of concentration hysteresis and effect on them of the particle size of the active component were defined.

The effect of reduction temperature of a Pt/WO₃/ZrO₂ catalyst (200–500 °С) on indicators of n-heptane isomerisation was studied. It was found that the maximum yield of the desired reaction products that are high-octane di- and trimethyl-substituted (DTMS) n-heptane isomers was reached (27–31 mass %) in the region of the 250–300 °С. A rise in reduction temperature of the catalyst to 400–500 °С leads to an increase in the number of Lewis acid sites in 1.6–1.7 due to partial reduction of tungsten on the WO₃/ZrO₂ surface, which contributes to an increase in the catalyst activity; herewith, selectivity by the target products decreases due to enhancing side reactions of n-heptane cracking.

The study results of acidity in a series of borate-containing aluminium oxide with the B₂O₃ content from 2.0 to 31.4 mass % (butenes oligomerisation catalyst) and a nickel-containing ethane oligomerisation catalyst obtained on its base were presented using the ESR spin probe method. The correlations between catalytic properties and the amount of nickel adsorbed with the concentration of Brønsted acid sites (BAS) determined using the probe molecules perylene were found: an increase in the concentration of BAS determinable with perylene in systems leads to a rise in the butenes conversion degree, the yield of oligomerisation products, and also to an increase in the amount of nickel adsorbed.

The structures of two isostructural phases of [ M (Еn)₃](ReO₄)₂ ( M = Ni, Zn; Еn is ethylenediamine) are studied. The crystal structures belong to the triclinic system, but demonstrate a pseudohexagonal packing motif. It is shown that the product of thermal decomposition of [Zn(Еn)₃](ReO₄)₂ (hydrogen atmosphere, 400 °C) is a homogeneous mixture of nanocrystalline zinc and rhenium powders with coherent scattering regions of ~30 nm.

The crystal structures of isostructural mixed-ligand fluorosulfate complex compounds of indium(III) M₂[InF₃(SO₄)H₂O] (M = K, NH₄), formed of K⁺ cations, NH₄⁺ respectively, and complex [InF₃(SO₄)H₂O]^2- anions are determined. In the complex anion, the indium atom surrounded by three F atoms, the oxygen atom of the coordinated H₂O molecule, and two oxygen atoms of the bridging sulfate group forms a slightly distorted octahedron (CN 6). Via alternating bridging SO₄ groups, the polyhedra of In(III) atoms are arranged in polymer chains. The O-H⋯F hydrogen bonds organize the chains in a three-dimensional network. The K⁺ and NH₄⁺ cations are located in the structure framework and additionally strengthen it.

A new dimeric compound [{UO₂(μ-OH)(terpy)}₂](ClO₄)₂×0.67CH₃CN, containing an uranyl cation and a tridentate 2,2':6',2"-terpyridine (terpy) ligand, is synthesized from an acetonitrile solution of uranyl perchlorate and terpy. The crystal structure of the compound is determined by single crystal X-ray diffraction. The crystal structure shows the formation of symmetric and asymmetric cationic hydroxo-bridged uranyl dimers. The uranium atoms adopt a distorted pentagonal bipyramidal configuration with a UO₄N₃ coordination environment formed by two uranyl O atoms, three N atoms from the terpy ligand, and two O atoms from the hydroxide anions.

The X-ray diffraction study of new derivatives of perchlorate (9Н-xanthene-9-yl) and (4H-chromen-4-yl) triphenyl phosphonium is performed. It is demonstrated that the change in the molecular structure leading to a change in the degree of benzoannelation does not affect the phosphorus-carbon bond length. It is determined that perchlorate (2-phenyl-4Н-chromen-4-yl) triphenyl phosphonium сrystallizes as two polymorphs.

The crystal structure of the bimolecular crystal of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and methoxy- NNO -azoxymethane (МАМ) (1:2) is studied. The CL-20 molecules adopt a z-conformation. The crystal structure is formed by layers of CL-20 and МАМ molecules, between which there are shortened NO^d-⋯N^d+O contacts of the neighboring CL-20 and МАМ molecules.

Based on thermodynamic simulation data on the deposition of condensed phases with the complex composition in the Si-C-N-O-H system in a wide temperature range, using initial gas mixtures of 1,1,3,3-tetramethyldisilazane (HSi(CH₃)₂)₂NH (TMDS), TMDS with a variable mixture of oxygen and nitrogen (O₂+ xN₂), a method is developed to obtain SiC_xN_yO_z:H nanocomposite films by the plasma chemical decomposition of this gas mixture in the temperature range of 373-973 K. By FTIR and energy dispersive X-ray spectroscopy the structure of chemical bonds and the elemental composition of the obtained silicon oxycarbonitride films are studied. The in situ composition of the initial gas phase in PECVD processes is examined by optical emission spectroscopy.

A complex of physicochemical methods (powder XRD analysis, transmission and scanning electron microscopy, electron spectroscopy of diffuse reflectance, low-temperature nitrogen adsorption) is used for the comparative study of structural and morphological properties of oxide supports Ce_{1- x} M _x O _y (M = Gd, La, Mg; x = 0-0.5; 1.5 ≤ y ≤ 2.0) for catalysts for the autothermal reforming of bioethanol to a hydrogen-bearing gas. It is shown that Ce_1-x M _x O _y samples synthesized by the method of ester polymer precursors are mesoporous materials being the homogenous substitutional solid solutions with the fluorite-type cubic structure. The structural and textural properties of the Ce_1-x M _x O _y materials are regulated by varying the type of the dopant cation (M = Gd, La, Mg), the molar ratio M/Ce (0, 0.1, 0.25, 1), and heat treatment conditions (temperature 300-800 °C; duration 4-24 h). The relationship between the synthesis parameters and the characteristics of the Ce_1-x M _x O _y materials is found.

The work reports different forms of solid solution ordering: from the well-known atom redistribution processes over positions and the decomposition of the solid solution to the formation of superstructures, modulated structures, rotation of atomic groups, splitting of sites. For each ordering form as a crystal chemical phenomenon the position of atoms, molecules, and vacancies in the crystal structure of the solid solution is considered and the place of these processes among the main crystal chemical phenomena is determined. The manifestation of order-disorder processes in phase diagrams of systems is also analyzed: from the classical heterogeneous decomposition of solid solutions to the formation of ordered chemical compounds and other phase transitions. The necessity of a thorough study of the atomic-molecular nature of the solid solution ordering by modern X-ray diffraction crystallographic methods and high-resolution electron microscopy is demonstrated. For each ordering form examples are given, the driving force of the process is distinguished, and a brief literature review is presented.

The molecular dynamics method is used to study liquid aqueous solutions of helium and neon, liquid water films and solid films with an ice II structure in helium and neon atmospheres, and solid solutions of helium and neon in ice II. Gas atoms wander randomly in water and make occasional slow jumps. The structure of the hydrate shell of the gas atoms bears little resemblance to the structure of ice II and other ice modifications. The solubility of neon in a water film is only a little higher than that of helium. Helium and neon atoms that find themselves in the channels of a thin ice II film make the same jumps along the channels as those along the channels in the structure of ice II crystals. The motions of two neon atoms in the neighboring (along the z axis) planes are correlated, whereas there is no correlation between the motions of helium atoms.

The solvent effects on the NH stretching of 1-(4-pyridyl)piperazine (1-4pypp, C₉H₁₃N₃) are investigated by density functional theory (DFT). The B3LYP hybrid density functional is used with the 6-311+G(3df,p) basis set in the polarizable continuum model (PCM). Computations are performed with 18 different polar or non-polar solvents. The calculated frequencies of the solvent-induced NH stretching vibrations are correlated with some solvent parameters such as the Kirkwood-Bauer-Magat (KBM) equation, the solvent acceptor number (AN), Swain parameters, and the linear solvation energy relationships (LSER). The present work explores the effects of the medium on the n(NH) vibrations. The findings of this research can be useful for piperazines.

The C₂₀ (cage), C₂₀ (bowl), C₂₀H₁₀ (bowl) fullerene structures and their nitrogen doped derivatives such as C₂₀NH (cage), C₂₀NH (bowl), C₂₀H₁₀N (bowl), C₂₀H₁₀NH (bowl) are fully optimized at the MPW1PW91/6-31G level of theory. The natural atomic charge comparison shows that in C₂₀H₁₀N (bowl), the nitrogen atom with about -0.58 has a more negative charge with respect to other nitrogen doped structures. The nuclear magnetic resonance chemical shielding is evaluated for nitrogen doped structures and the neighbors connected to nitrogen, C₆, and C₇ atoms. The nitrogen atom doped on carbon sites of C₂₀H₁₀N (bowl) has the largest shielding isotropic shifts to the upper field (-203.58 ppm). This means that the electron density around nitrogen in the C₂₀H₁₀N (bowl) structure is higher. Interestingly, there is a significant correlation between the charges and s_iso values of nitrogen and carbon atoms (C₆ and C₇). Namely, as the charge becomes more negative, s_iso shifts to the upper field. It is predicted that nitrogen doped C₂₀H₁₀N (bowl) with the maximum electron density adopts this structure for electrophilic reactions.

Zinc halide complexes of thionicotinamide (TNA) having the general formula [Zn(TNA)₂X₂] (X = Cl^-, Br^-, I^-) are prepared and characterized by thermal analysis, IR and NMR spectroscopy. The crystal structure of one of them, dichloridobis(thionicotinamide-kN)zinc(II), [Zn(TNA)₂Cl₂] (1), is determined using X-ray crystallography. In 1, the zinc atom is coordinated by two thionicotinamide ligands through nitrogen atoms and two chloride ions in a distorted tetrahedral coordination environment. The molecular structure of the complex is stabilized through intermolecular hydrogen bonding.

Voltaite of the composition [K_0.90(NH₄)_0.10]₂(Fe_3,190²⁺Fe_1,124³⁺Mg_1,686)(Fe_0,938³⁺Mg_0,062)₂(Al_0,98Fe_0,02³⁺)×(SO₄)₁₂x18.9H₂O is obtained by treating a polymetallic sample with sulfuric acid. The crystal structure of the substance is formed of (Fe³⁺,Mg)O₆ and (Fe²⁺,Fe³⁺,Mg)O₄(H₂O)₂ octahedra and a (K⁺,NH₄⁺)O₁₂x12-vertex polyhedron arranged in a three-dimensional framework due to the bridging function of the SO₄^2- ion. In the framework voids, [(Fe³⁺,Al)(H₂O)₆]³⁺ cations with aqua ligands disordered over several positions are located.

A new complex [Cu₂(L)₄(DMF)₂] (1) with benzoic acid (HL) as a ligand is synthesized by the solid phase synthesis method. Crystal data for the complex are as follows: monoclinic, space group P2₁/n, a = 10.593(2) Å, b = 10.123(2) Å, c = 16.336(3) Å, β = 93.55(3)°, V = 1748.4(6) ų, D_c = 1.439 g/cm^-3, Z = 4, F (000) = 780, GOOF = 1.003, final discrepancy factors R₁ = 0.0624, wR₂ = 0.1559. In 1, the Cu(II) ion is coordinated by six atoms to give a distorted octahedral coordination geometry. The electrochemical, fluorescent, and magnetic properties of 1 are studied. The results show that the electron transfer of 1 is quasi reversible in the electrode reaction corresponding to Cu(II)/Cu(I), and 1 exhibits three relatively strong fluorescent emission peaks at 403, 425, and 454 nm. In addition, complex 1 displays the antiferromagnetic property in a temperature range of 300 ~ 10 K.

A new mixed-ligand copper(II) complex of 1,10-phenanthroline and nitrate ligands [Cu(C₁₂H₈N₂)(NO₃)₂] _n is prepared and its crystal structure is determined by X-ray diffraction. The complex crystallizes in the monoclinic space group P21/n, with unit cell dimensions a = 8.8226(3) Å, b = 9.1462(1) Å, c = 17.2507(4) Å, β = 101.680(2)°, Z = 4, V = 1363.19(6) ų. The crystal structure is solved by the Patterson method and refined by full-matrix least squares treatment on F ² to final values R1 = 0.0447 and wR2 = 0.1053. The Cu^II ions are five-coordinated in a CuO₃N₂ environment, giving a distorted square-based pyramidal geometry. The Cu…Cu distance in the [Cu(C₁₂H₈N₂)(NO₃)₂] _n zigzag polymeric chain is 5.258(1) Å. The structure of the title compound is polymeric and consists of layers running parallel to (101), interconnected by π-π interactions, strong enough to form a three-dimensional framework with tunnels along the a axis.

Two iridium acetylacetonate complexes bearing axial bromide-substituted pyridine (3-bromopyridine, 1 and 4-bromopyridine, 2) are synthesized and their crystal structures are determined by single crystal X-ray diffraction. In both complexes, a distorted octahedral geometry of the central Ir(III) atom is formed by four oxygen atoms of two acetylacetone ligands, a carbon atom of one acetylacetone ligand, and a nitrogen atom of bromide-substituted pyridine.

Rhenium-molybdenum cluster compounds K_5.3Rb_0.7[Re₃Mo₃S₈(CN)₅] (1) and K_4.4Cs_1.6[Re₃Mo₃S₈(CN)₅] (2) are obtained by the interaction of an equimolar mixture of ReS₂ and MoS₂ with molten KCN and RbI/CsCl, respectively. The structure of the complexes is determined by the XRD method. The compounds crystallize in the tetragonal crystal system, space group I4/m. The crystal structure is composed of anionic chains of [Re₃Mo₃S₈(CN)₄(CN)_2/2]^6- aligned along the a crystallographic axis and M⁺ cations located in voids of the lattice. The effect of additional Cs⁺ and Rb⁺ cations on the crystallographic parameters and geometric characteristics of the clusters is analyzed.

Isostructural fluorooxalate complex compounds of indium(III) M₂[InF₃(C₂O₄)H₂O] (M = K, Rb), being the first representatives of a new class of mixed-ligand fluoro-containing complex compounds of indium(III) are synthesized for the first time and structurally studied. The crystal structures of M₂[InF₃(C₂O₄)H₂O] (M = K, Rb) are formed of K⁺ cations (Rb⁺ respectively) and complex [InF₃(C₂O₄)H₂O]^2- anions. The indium atom in the complex anion is surrounded by four F atoms, two of which are bridging, the oxygen atom of the coordinated H₂O molecule, and two oxygen atoms of the bis-bidentate (tetradentate) oxalate group. The coordination polyhedron of the indium atom (CN 7) is a pentagonal bipyramid. Via alternating double bridging F atoms and tetradentate bridging C₂O₄ group, the In(III) atom polyhedra are arranged in polymer chains. Via hydrogen O-H⋯F bonds the chains are organized in layers. Between the layers, the K⁺ or Rb⁺ cations are located, which strengthen the crystal structure.

The salt 1-(4-trifluoromethyl-2,3,5,6-tetrafluorophenyl)-3-benzylimidazolium bromide [(CF₃C₆F₄)NC₃H₃N(CH₂Ph)]⁺×Br^- is crystallized from methanol in the space group P-42₁c of the tetragonal crystal system with unit cell parameters a = b = 21.6531(3) Å, c = 8.1968(2) Å, V = 3843.13(13) ų, Z = 8, d_calc = 1.5732 g/cm^-3. The structure possesses square channels with a width of ca. 5.2 Å, which accounts for 14 % of the volume, and contains one methanol molecule per ion pair. The cation interacts with three bromide ions through an anion - π interaction and two C-H⋯Br^- interactions. These interactions are investigated by DFT calculations.