Home – Home – Jornals – 2012 number 6

The localization of heat release during deformation of a notched steel plate is studied. It is shown that the source of heat generation in the metal specimen is not the whole region of plastic deformation near the tip of the defect (crack), but only the slip bands occupying the relatively small part of the zone (Chernov–Luders bands), in which the deformation initiates physical and chemical processes. It was found that in the slip bands, the metal temperature increases by several tens of degrees (or more). The deformation of notched specimens is characterized by uneven development of plastic deformation in the volume of the material and a high velocity of heat-wave propagation in the direction of the maximum slip stresses.

Problems of nonlinear cylindrical bending of sigmoid functionally graded plates in which material properties vary through the thickness are considered. The variation of the material properties follows two power-law distributions in terms of the volume fractions of constituents. The nonlinear strain-displacement relations in the von Kármán sense are used to study the effect of geometric nonlinearity. The governing equations are reduced to a linear differential equation with nonlinear boundary conditions, yielding a simple solution procedure. Numerical results are presented to show the effect of the material distribution on the deflections and stresses.

Matching conditions simulating a transverse notch in a beam are proposed. These conditions are used to determine the location and size of the notch. The notch is identified from beam deflections at several points in the static case and from the first eigenfrequencies of the beam in the dynamic case. Dependences of the first eigenfrequencies on the characteristic parameters of the problem are obtained. The effect of the relative error of frequency measurements on the relative error of calculation of the notch parameters is studied. It is shown that the use of the first eigenfrequencies of flexural vibrations of the beam with respect to different axis provides a more accurate identification than the use of eigenfrequencies of flexural vibrations relative to one axis. Since local defects such as hollows, local corrosion, and an open crack can be simulated by a notch, the results can also be used to identify these defects.

A model of a fractal crack is considered. It is found that the limiting velocity of crack propagation is determined by the fractal dimension of the crack contour. It is shown that for commercial steels, the limiting crack velocity is in the range V_lim = (0.155 ÷ 0.537)c₁ (c₁ is the speed of sound).

Analytical solutions of a number of one-dimensional quasi-static problems that describe the processes of elastic deformation of the material of a hollow sphere and of generation and development of the plastic flow in this material with increasing pressure on the external boundary are presented. The process of unloading during slow removal of the loading pressure is studied. Stress fields, fields of elastic and plastic strains in the material of the spherical layer, the law of motion of the elastoplastic boundary, and residual stresses are determined. It is demonstrated that (in contrast to the ideal plasticity case) the allowance for the viscous properties of the material during its plastic flow eliminates the possibility of plastic flow emergence during unloading.

Materials with a regular structure characterized by quasi-brittle and quasi-ductile fractures are considered in the case where the characteristic linear dimension of the structural element is known. Necessary and sufficient fracture criteria are constructed using the Neuber–Novozhilov approach. A modified Leonov–Panasyuk–Dugdale model for an opening mode crack is proposed where the width of the prefracture zone coincides with the width of the plasticity zone. For the critical parameters of quasi-brittle fracture (tensile stress, length of prefracture zones, stress intensity factors), relations are obtained that allow material fracture to be considered in the case where the crack length is negligible compared to the characteristic linear dimension of the structural element. A fracture diagram obtained using the critical stresses calculated from the necessary and sufficient criteria is considered in a wide range of crack lengths. The elastoplastic problem of extension of a plate with a central crack is solved using the finite-element method. The dimensions and shape of the plastic zone near the crack tip are determined for different levels of loads corresponding to quasi-brittle and quasi-ductile fracture. The obtained results are analyzed to estimate the width of the prefracture zone and the critical crack opening.

Experiments studies which showed are carried out that stress hormones (a cortisol, adrenaline) can bind to erythrocyte membranes with high affinity, leading to rough structural changes. The last are accompanied by increase of microviscosity of membranes as in area a lipid-lipid, and protein-lipid of interactions. The nature of these changes is caused by simultaneous interaction of active groups of hormones (NH, OH and their waterproof rings) at the same time with a lipid and protein components of a membrane with formation of domains. Experiments with heart perfusion of rats showed that erythrocytes with the increased microviscosity of their membranes are incapable to move ahead on the capillary course that leads to sharp decrease in a coronary stream and fast cardiac arrest. The assumption is come out that this mechanism is shown and at a coronary syndrome X at the person

Purpose: to analyze population values of the main blood lipid parameters of Novosibirsk inhabitants depending on sex and age. Materials and methods. The materials of the two large international projects called MONIСA and HAPIEЕ was used. According to these projects protocols, representative samples of unorganized population of Novosibirsk were studied. The analysis included data of 11,537 people aged 45-64, 5,445 men and 6,092 women among them. Results. Persons of both sex aged 45-64 had mean values of total cholesterol (TC), non-high density lipoproteins cholesterol (Ch-non-HDL), low density lipoproteins cholesterol (Ch-LDL) of serum equal to 6.05; 4.57; 3.93 mmol/l, respectively. Women aged 45–64 had the above blood parameters higher than men of the same age. Both men and women of 45–54 had higher blood TC, Ch-non-HDL, Ch-LDL levels than the ones aged 55–64, although women had more significant age dependent dynamics of the above blood lipid parameters than men. Blood triglycerides level in women was lower in 45–54 age group than in 55–64 decade; no differences were detected in men of these age groups. Blood triglycerides content in men aged 45–54 was higher, and in 55–64 age group it was lower than in women of the corresponding age. The same data was also received for atherogenic indexes (AI). Conclusion. Mean values of blood TC, Ch-non-HDL, Ch-LDL in population of Novosibirsk aged 45–64 exceed the optimal ones. Values of the above blood lipid parameters are higher in women than in men, and are also higher in senior age group compared to junior one. Whereby age dependent dynamics of atherogenic fractions in women aged 45–64 is more demonstrative than in men. AI in men of 45–54 age group is higher, and in 55–64 age group it is lower than in women of the same age.

Myocardial infarction (MI) continues to be one of the most important problems of modern cardiology in Russia due to maintaining a sustainable morbidity and mortality. Of particular interest are the growth of the relationship of cardiovascular disease and myocardial infarction with the accumulation in the population of persons with obesity and other metabolic disorders. Now to have a clear view of the relationship of metabolic syndrome and cardiovascular disease. Mechanisms of metabolic syndrome, including insulin resistance, hyperinsulinemia, chronic inflammation, run and maintain a high level atherogenesis, endothelial dysfunction, provoke instability of coronary plaque, thrombus formation processes. This is a strong incentive to continue research in this area, which should help to find new ways of preventing MS to reduce the possible coronary risk, affect the outcome of treatment and to determine the characteristics of MI, developed on the background of MS.

In all the patients with the stage III of arterial hypertension dislipidemia was revealed. The atherosclerotic arterial changes result to cardiocerebral disorders. There are changes in the state of the venous cranial brain system simultaneously with the structural-functional change of the vitally important organs i.e. the heart and the brain. The quantity evaluation of the cerebral venous discirculation makes it possible to have the differential diagnostics of the hemodynamic disorders in vascular foci and predict the risk of acute cardiovascular complications in patients with arterial hypertension associated with atherosclerosis.

Thyroid dysfunction and dyslipidemia are closely connected by pathogenetic reason. During the last few years they have been discussing L-thyroxin influence on lipid profile. According to data obtained in various studies, lipid profile values normalization appears not in every case of euthyroidism. In the literature there is little information about statins administration risk and advantage during hypothyroidism. According to the literature, decompensated hypothyroidism can lead to myalgia and/or myopathy development accompanied by creatine phosphokinase concentration increase in patients on statins. There are several publications of clinical cases of rhabdomyolysis development against the statins treatment background in persons with undiagnosed decompensated manifest hypothyroidism. Thus, taking into account the risk of the rhabdomyolysis development, TSH level should be estimated before statins treatment almost in all cases.

The aim of this review is the assessment of prospects to use of extracorporeal methods in the treatment of atherosclerosis and atherogenic dyslipidemia in the modern medicine. Today there are different methods of treatment of severe atherosclerosis, which cause a positive rheological effect from the selective removal of harmful components from plasma. This methods are called rheopheresis and carried by using special cascade plasma filters (rheofilters), heparin-LDL-precipitation (HELP) and provides the immunoadsorption of low-density lipoproteins (LDL) and apolipoprotein(a) (Lp(a)). This improves blood flow and microcirculation, which caused by decrease viscosity in blood and plasma. The Сascade Plasmafiltration (CPP) with special rheofilters, HELP and immunoadsorption of LDL and Lp(a) improves the blood rheology and microcirculation most effectively in patients with severe hypercholesterolemia. The aim of extracorporeal methods of treatment of coronary heart disease is the correction of metabolism (normalization of lipid metabolism, state of coagulation), blood viscosity, improvement of microcirculation, increase of myocardial perfusion and tolerance to the drug therapy. The Plasmapheresis is one of the most simple and accessible extracorporeal methods, which effectively eliminate macromolecular structures. The Plasmapheresis is use in the combination treatment of patients with familial hypercholesterolemia, homozygous and heterozygous (refractory to lipid-lowering therapy). The Plasmapheresis is a non-selective methods of blood correction. This explains a significant therapeutic range of this method.

The disc-like cluster C₇₂H₁₀₂N₁₂Ni₁₃O₄₀ is first time synthesized based on N-(2-pyridyl)methylimino-dipropionic acid. Single crystal X-ray diffraction is used to determine its atomic structure. The cluster consists of seven-nuclear core: nickel(II) hydrocomplex (Ni…Ni distance 3.012-3.032 Å) and six nickel chelates of the corresponding acid arranged around its perimeter (Ni…Ni distance 2.981-3.164 Å). In the chelate part of the complex, the ligand is pentadentate owing to the formation of a bridging bond, thus organizing a coordination geometry of the metal center as a distorted square bipyramid (4+2). Liquid chromatography-mass spectrometry is employed to study the structure of the obtained nickel(II) complexes.

Based on the similarity of subgraphs in the molecular graphs of a homological series of SiH₄–SiC₈H₂₀ alkylsilanes a 22-constant additive scheme is obtained for the calculation of their physicochemical properties. By the example of SiH₄–SiC₈H₂₀ alkylsilanes it is shown that for each alkylsilane molecule the sum of numbers of simple and complex heterochains equals a triangular number. A least squares method is applied to determine the numerical values of the parameters of the scheme for the calculation of Δ_fH_{газ,298 K}⁰ for alkylsilanes (SiC_nH_2n+4).

The structure and stability of endohedral TM@(AlN)₁₂ (TM = Ti, Mn, Fe, Co, Ni ) complexes are studied at the level of density functional theory. It is found that complexes with TM = Mn, Fe, and Ni are energy minimum structures with TM at the cage center in T_h symmetry, while those with TM = Ti and Co have more negative inclusion energies and the off-centered structures with TM placed towards one hexagon face in C₁ symmetry. The calculations predict that the HOMO and LUMO energy gap of TM@(AlN)₁₂ differs from those of the (AlN)₁₂ cage and a free TM atom. The amount of charge that is transferred from the encapsulated guests to the cage increases with the atomic radius. The electronic and magnetic properties of TM@(AlN)₁₂ are discussed.

5,6-Dihydrothymine (DHT) is a nucleobase lesion induced by the action of ionizing radiation on thymine residue in DNA. In this work, we present the hydrogen bonding base pairs involving 5,6-dihydrothymine bound to four bases in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). Full geometry optimizations are performed for the studied complexes by the B3LYP method. Interaction energies are corrected for the basis set superposition error, using the full Boys-Bernardi counterpoise correction scheme. Hydrogen bonding patterns of these base pairs are characterized using NBO and AIM analysis. According to the calculated binding energies and structural parameters, the stability of the base pairs decrease in the following order: DHT:G ~ DHT:A > DHT:C > DHT:T.

A complex experimental study of Cu(2p_3/2), Cu(2p_1/2) photoelectron and Kα_1,2 and Lα_1,2 X-ray emission spectra of copper in copper phthalocyanine CuPcH₁₆ and its fluoro-substituted analog CuPcF₁₆ is carried out. A charge transfer model is used to interpret the spectra. It is shown that Kα₁ and Kα₂ lines of the spin-doublet of copper have a complex structure due to the processes of metal-to-ligand charge transfer. The role of a satellite in the formation of emission lines is revealed.

The microwave spectrum of 2,5-dimethyl-1,3-dioxane is studied. The spectrum is identified to have the а and с type rotational transitions of the trans- and cis-isomers of the molecule. The experimental frequencies of the transitions are used to calculate the rotational constants and the quartic centrifugal distortion constants of the isomers. The dipole moments are determined. Quantum chemical calculations are performed by the B3PW91/aug-cc-pVDZ density functional method. The calculated results are compared with the experimental data. The equilibrium geometries of 1,3-dioxane and 2-methyl-, 5-methyl-, and 2,5-dimethyl-1,3-dioxanes are compared. It is found that the alkyl substitution leads to a change in the ring geometry.

An iron(III)-containing complex with the asymmetric tridentate azomethine ligand 4,4'-dodecyloxy-benzoyloxybenzoyl-4-salicylidene-N'-ethyl-N-ethylenediamine with a PF₆^- counterion is obtained. The presence of the complexing ion is confirmed by far IR Fourier spectra. The structure of the compounds is determined by matrix-assisted laser desorption/ionization with a time-of-flight mass analyzer (MALDI-ToF). The results of mass spectrometric studies are consistent with the elemental analysis data. It is found that the complexation of iron salt with an asymmetric tridentate ligand results in the formation of compounds of the composition 1:1 with octahedral packing of a metal ion in the complex. The electrochemical behavior of the compound in organic solvents is examined. The EPR study shows that iron(III) ions are in both low spin (LS) and high spin (HS) states in the complex. The LS and HS iron(III) centers are coupled into dimers in which a water molecule and the PF₆^- counterion act as bridges. It is also found that for LS complexes in the low-temperature phase (4.2-300 K), the (d_xz, d_yz)⁴(d_xy)¹ electronic state is the ground state. It is revealed that the conversion of the sample into a high-temperature liquid crystalline (387-405 K) phase is accompanied by the conversion of the LS states of the Fe(III) ion: (d_xz, d_yz)⁴(d_xy)¹ ↔ (d_xy)²(d_xz, d_yz)³. The conversion of LS states is temperature reversible and is driven by the temperature. X-ray crystallographic data confirm that the compound obtained consists of dimer formed by a hydrogen (O–H⋯F) bond.

Quantitative structure-spectrum relationship calculations of ¹³C NMR chemical shifts of both 302 carbon atoms in 56 alcohols and 62 carbon atoms in 15 thiols are described using several parameters: the atomic ionicity index (INI), the polarizability effect index (PEI), and stereoscopic effect parameters (ε) of the compounds. The ¹³C NMR chemical shifts for these compounds of both alcohols and thiols can be estimated through the multiple linear regression (MLR). A MLR model was built with variable screening by the stepwise multiple regression and examined by validation on its stability. The correlation coefficient of the established model as well as the leave-one-out cross-validation was 0.9724 and 0.9716 respectively. The results obviously indicate that INI and e are linearly related with ¹³C NMR chemical shifts, which provides a new method for calculating ¹³C NMR chemical shifts in the compounds of both alcohols and thiols.

UV spectroscopy is used to determine the molar absorption coefficients of C₆₀ fullerene and monosubstituted 1,2-dihydro-C₆₀-fullerenes in different solvents. It is found that the extinction coefficient of C₆₀ at 330 nm (the main absorption band most frequently used for qualitative and quantitative determination of the C₆₀ content) is independent of the nature of the solvent and is ~54400 M^–1×cm^–1. The molar absorption coefficients of a series of monosubstituted 1,2-dihydro-C₆₀-fullerenes are practically independent of the chemical structure and the length of the substituent and are 35700 M^–1×cm^–1 (λ ~ 328 nm) and 115250 M^–1×cm^–1 (λ ~ 257 nm). It is shown that the substitution in fullerene proceeds via the double 6,6 bond, as evidenced by the absorption band at 424 nm in the spectra of these compounds, which is characteristic of monosubstituted methanofullerenes.

The problem of the introduction of the term "internal pressure" from the standpoint of intermolecular forces is solved. It is shown that internal pressure is created by the macrosystem average force field of the structural units of a liquid. Internal pressure is shown to be not an energy characteristic, but a macrosystem average force parameter of the interaction between the structural units of a liquid phase system, although it has the energy density dimension, [J/m³].

The hydration numbers are investigated of the glycine amino acid in solutions of substances with different effects on the structure of water: urea, monomethylurea, and 1,3-dimethylurea. Glycine loses a half of its hydration water in a 20m urea solution and only a quarter of it in a 20m dimethylurea solution. The constancy of the hydration number of glycine in concentrated dimethylurea solutions is due to the compensatory effect of the interactions in the ternary and binary systems.

Specific features of the structure and phase composition of coatings obtained by the action of shaped charge jets are studied. Different molybdenum-containing compounds are used as precursors.

The molecular and crystal structure of halogen-substituted acetylacetonates of boron difluoride 2,2-difluoro-5-chloro-4,6-dimethyl-1,3,2-dioxaborin (1) and 2,2-difluoro-5-bromo-4,6-dimethyl-1,3,2-dioxaborin (2) is determined. In both compounds, a noticeable intermolecular interaction between the fluorine and carbon atoms of the chelate ring and between the fluorine atoms and substituents exists. In order to explain the revealed patterns of molecular packing, the charge distribution in the studied chelates is calculated.

The crystal structure of a solvate [Zn(НL)Cl]×EtOH is determined by single crystal X-ray crystallography (150 K, Bruker X8 Apex CCD autodiffractometer, МоK_a radiation). The crystals are triclinic, unit cell parameters are: a = 7.4755(4) Å, b = 13.9701(11) Å, c = 14.4593(19) Å, α = 82.277(2)°, β = 75.410(2)°, γ = 75.356(1)°, space group Р1. The structure of the solvate contains two crystallographically independent complex [Zn(НL)Cl] molecules and two non-coordinated ethanol molecules. In each of the molecules, Zn²⁺ ions coordinate N atoms of tetradentate chelating ligands НL^– and a Cl atom. ClN₄ polyhedra have a distorted tetragonal pyramidal geometry. EtOH molecules make H-bonds with the complex molecules, thus facilitating the formation of chains along the х axis.

Two new malonato-bridged copper(II) complexes of the composition [Cu ₂(mal) ₂(datz) ₂(H ₂O)]×5H ₂O (1) and [Cu ₂(mal) ₂(atz) ₂(H ₂O)]×3H ₂O (2) (mal = malonate, atz = 4-amino-1,2,4-triazole, datz = 3,5-diamino-1,2,4-triazole) are prepared and characterized by X-ray crystal structure determination and magnetic studies. The environment of each copper atom in 1 and 2 has distorted square pyramidal and octahedral geometries. The intrachain copper-copper separation is 6.305 Å and 3.640 Å across the carboxylates and trizolates bridges respectively for complexes 1 and 2. The magnetic properties of 1 and 2 are investigated in the temperature range 2—300 K. The overall antiferromagnetic behavior is observed in both cases.

A single crystal X-ray study of a novel volatile trans -isomeric complex of palladium Pd(L) ₂, obtained based on sterically hindered methoxy-β-iminoketone (HL = C(CH₃)₂(OCH₃)–C(NH)–CH₂–C(O)–CH(CH₃)₂), is performed. The crystallographic data for C₂₀H₃₆N₂O₄Pd are: a = 10.0408(2) Å, b = 9.9473(2) Å, c = 11.6413(2) Å, β = 96.789(1)°, space group P2₁/c, Z = 2. The structure is monomeric molecular; the palladium atom has a square coordination with two oxygen and two nitrogen atoms of two bidentately bound ketoiminate ligands in the trans-position. Geometric characteristics of the coordination sites: the bond length of Pd–O, Pd–N and the chelate N–Pd–O bond angle are 1.986 Å, 1.974 Å and 93.1° respectively. It is found that Pd, Ni, and Cu complexes with this ligand are isostructural.

Potassium salts of chalcohydroxo rhenium cluster complexes [Re₆Q₈(OH)₆]^4– (Q = S or Se) with the composition K₄[Re₆S₈(OH)₆]×4H₂O (1) and K₄[Re₆Se₈(OH)₆]×5H₂O (2) are produced by evaporation of the corresponding strongly alkaline aqueous solutions. The composition of the compounds is determined by the single crystal X‑ray diffraction study. The compounds crystallize in the triclinic space group P1^– with the following unit cell parameters: a = 8.408(2) Å, b = 9.096(2) Å, c = 9.222(2) Å, α = 95.110(4)°, β =107.085(4)°, γ = 113.026(4)°, V = 603.5(3) Å ³, Z = 1, d_x = 4.689 g/cm ³ (for 1) and a = 8.782(3) Å, b = 9.155(4) Å, c = 9.325(4) Å, α = 105.481(7)°, β = 109.266(6)°, γ = 99.104(6)°, V = 656.6(4) Å ³, Z = 1, d_x = 5.305 g/cm ³ (for 2).

The crystal structure of double complex salt [Pt(NH₃)₅Cl][ReCl₆]Cl×H₂O is determined. Crystallographic characteristics are: a = 23.9502(4) Å, b = 7.5963(1) Å, c = 8.9016(2) Å, V = 1619.49(5) ų, space group Pnma, Z = 4, d_x = 3.150 g/cm³. The packing of structural fragments is studied. It is shown that on heating the salt in a helium atmosphere up to 840 °С a mixture of two solid solutions of fcc Pt_0.90Re_0.10 and hcp Pt_0.25Re_0.75 forms.

The (EnH₂)[AuCl₄]₂×2H₂O (I) and (EnH₂)₂[AuCl₄]Cl₃ (II) (EnH₂²⁺ is diprotonated ethylenediamine) complexes are produced and characterized by elemental and thermogravimetric analysis, X‑ray diffraction, IR and Raman spectroscopy. For I, the crystals are monoclinic, crystallize in the space group P2₁/c: a = 7.5870(2) Å, b = 9.5665(2) Å, c = 11.4706(3) Å, β = 107.0480(10)°, V = 795.97(3) ų, Z = 4. For II, the crystals are orthorhombic, crystallize in the space group Pnma : a = 12.7088(3) Å, b = 17.7435(5) Å, c = 7.4992(2) Å, V = 1691.06(8) ų, Z = 8.

The X‑ray diffraction study of cis-2,3-dichlorobuth-2-ene-1,4-diol (3) obtained by the reduction of 3,4-dichloro-5-ethoxy- and 5-isopropoxi-2(5H)-furanones with lithium aluminum hydride is performed. The crystals of compound 3 are trigonal: a = b = 15.746(9) Å, c = 6.848(4) Å; V = 1470.5(15) ų, space group P3₁, Z = 9 (three independent molecules). Independent molecules have identical planar conformation, and hydroxyl groups are located on different sides of the multiple bond plane. The supramolecular motif of the crystal is spirals about the threefold screw axes; the neighboring spirals are linked by OH…O hydrogen bonds.

The title compound (2,6-di- tert -butyl-4-(3-(4-chlorophenyl)-4-methyl-4,5-dihydroisoxazol-5-yl)phenol is synthesized and studied by the single crystal X-ray diffraction method. The structure of the product was confirmed by IR, ¹H and ¹³C NMR spectroscopy. The crystal structure of 1,4-dioxane hemisolvate of the product is solved in the monoclinic space group P2₁/c with a = 17.713(6), b = 9.529(3), c = 13.972(4) Å, β = 94.09(4)°, V = 2352.3(13) ų, Z = 4, T = 120(2) K.

Magnetic resonance imaging (MRI) has become a prominent imaging technique in medicine. Gadolinium-based contrast agents are extensively used to enhance the contrast between normal and diseased tissues through MRI scans. The article illustrates the paramount significance of such contrast agents in MRI applications. Clinically approved contrast agents as well as those in trial period are discussed. Important parameters, i.e. hydration number, rotational correlation time, and mean residence lifetime, influencing the relaxivity (sensitivity) of such agents are described in detail. Various approaches towards relaxivity enhancement are discussed with appropriate examples from the recent literature. A decrease in the Gd-water proton distance results in significant relaxivity enhancement. A comprehensive classification and explanation of Gd³⁺-based contrast agents are presented. Each class is explained with suitable examples. The stability of contrast agents is dependent on their chemical structure. Future contrast agents need to be tissue specific of high relaxivity, low toxicity, and lower administered dose for in vivo use.

The density functional theory method with B3LYP/6-311++G(df,pd), B3LYP/6-311++G(df,2pd), and B3LYP/6-311++G(3df,3pd) basis sets is used to compute the geometrics and single point energy of aluminum carbide (AlC) and aluminium nitride (AlN) in their ground state. The Level 8.0 program is used to calculate spectroscopic constants and fit the energy potential curves. The effect of a basis set on the spectroscopic constants is discussed. The results show that the calculated potential curve matches well with the Level 8.0 fitting curve, and the calculated values of spectroscopic constants become more reliable with the improvement of the quality of basis sets. The spectroscopic constants are in good agreement with the existing experimental and theoretical values. For the first time, the reliable anharmonicity constant data of AlC are reported, which agrees so well with the experimental value.

2p_3/2,1/2 Photoelectron spectra of single crystalline specimens of chromium-copper disulfides CuCrS₂ and CuCr_0.85V_0.15S₂ are studied. It is shown that the spectra of single crystalline specimens substantially differ from the corresponding spectra of chromium-copper disulfides in the powder state.

The ¹H, ¹³C, and ¹⁵N NMR chemical shifts of ten 4-nitropyridine N-oxide derivatives are assigned. The shielding of the pyridine ring nitrogen is sensitive to ring substitution through inductive effects, steric effects by ortho-substituents, and the possibility for electron delocalisation (resonance energy). In solution, 3-ethylnitrosoamino-4-nitropyridine N-oxide has two tautomers. The proposed reason is the steric crowding between vicinal 4-nitro and 3-ethylnitrosoamino groups, causing a disturbance to amino nitrogen that can delocalize its lone pair to the oxygen atom of the nitroso group.

The molecule (h⁵-pentamethylcyclopentadienyl)(methyldiphenylphosphinite-P)dichlororhodium(III), [(h⁵-C₅Me₅)RhCl₂(PPh ₂OMe)], crystallizes in the monoclinic crystal system in space group P2₁/c with unit cell parameters a = 16.056(3) Å, b = 9.4331(18) Å, c = 15.745(3) Å, β = 108.330(4)°, V = 2263.8(7) ų and Z = 4. There is three-legged piano stool geometry about Rh. The Rh—P distance of 2.278(2) Å is shorter than those of [(h⁵-C₅Me₅)RhCl₂(PPh₂OR)] where R is an aryl group, and longer than those found in [(h⁵-C₅Me₅)RhCl₂{PPh(OR)₂}]. The structure reveals significant distortion of the pentamethylcyclopentadienyl towards 'h³,h²-enyl-ene' coordination.

The Schiff base thiophenyl-2-methylidene-2-aminophenol (ImineOH) is obtained from a stoichiometric mixture of 2-thiophenecarboxaldehyde and 2-aminophenol in ethanol under reflux at 90 °C. Its crystal structure is determined by single crystal X-ray diffraction. ImineOH packs in an orthorhombic unit cell in the Pbca space group with the unit cell parameters a = 16.942(4) Å, b = 13.4395(11) Å and c = 17.5857(12) Å, V = 4004.1(10) ų, Z = 16. Strong hydrogen bonds are present in the ImineOH structure. Apart from the X-ray study, ImineOH was characterized by elemental analysis (CHN-S) and FT—IR (4000 cm^–1 to 400 cm^–1), UV-Vis and ¹³C, ¹H, and ¹⁵N NMR spectroscopic measurements.

The crystal and molecular structure of 4-chloro(benzoyloxymethyl)trifluorosilane 4-ClC₆H₄COOCH₂SiF₃ was redetermined using X‑ray diffraction. The coordination polyhedron of the silicon atom in this structure is a trigonal bipyramid. The length of the axial O → Si coordination bond is 2.074(1) Å.