Reactions that occur during the synthesis of 3-phenyl-5-phenoxymethyl-2-N-phenyliminooxazolidine

Conclusions 3-Phenyl-5-phenoxymethyl-2-N-phenyliminooxazolidine, formed by the reaction of diphenyl-carbodiimide with phenyl glycidyl ether, reacts with an excess of the latter to give 3-phenyl-5-phenoxymethyl-2-oxazolidone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2152–2153, September, 1983.     

Synthesis and X-ray crystallographic investigation of 3-phenyl-3-phenoxymethyl-2-oxazolidinone

Conclusions 3-Phenyl-5-phenoxymethyl-2-oxazolidinone is the product of interaction of phenylisocyanate with phenylglycidyl ether. Its molecule has a less strained conformation than the molecule of related 2-N-phenylimino-3-phenyl-5-phenoxymethyloxazolidine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 870–874, April, 1986.     

Thermodynamic properties of melts of SrO-B2O3 and BaO-B2O3 systems

Gibbs energies, activities, and chemical potentials of SrO, BaO, and B₂O₃ in melts of SrO-B₂O₃ and BaO-B₂O₃ systems within the temperature range of 1840–1970 K were determined. Significant negative deviations from the ideal behavior were found in the melts studied.     

Formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives

The Vilsmeier formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives was studied. It is shown that 2-phenyl-5-methoxybenzofuran is formylated in the 4 position, whereas 3-phenyl-5-methoxybenzofuran is formylated in the 2 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1023–1024, August, 1976.     

Thermodynamic properties of potassium metasilicate (K2SiO3)

The standard enthalpy of formation of potassium metasilicate (K₂SiO₃), determined by hydrofluoric acid solution calorimetry, was found to be ΔH^o_f,298 = −363.866±0.421 kcal mol⁻¹ (−1522.415±1.762 kj mol⁻¹). The standard enthalpy of formation from the oxides was found to beΔH^o₂₉₈ = −64.786±0.559 kcal mol⁻¹ (−271.065±2.339 kJ mol⁻¹).These experimentally determined data were combined with data from the literature to calculate the Gibbs energies of formation and equilibrium constants of formation over the temperature range of the literature data. The standard enthalpies of formation and Gibbs energies of formation are given as functions of temperature. The standard Gibbs energy of formation is ΔG_f,298.15⁰ = −341.705 kcal mol⁻¹ (−1429.694 kJ mol⁻¹).     

Thermodynamic properties of Co3O4 and Sr6Co5O15 from first-principles

The Gibbs energy function of Sr(6)Co(5)O(15) is calculated by first-principles for use in CALPHAD thermodynamic modeling. An efficient method is employed, using the Debye-Gru?neisen model to predict the temperature dependence of the heat capacity and entropy. The equation of state from first-principles and the Debye temperature from harmonic phonon calculations by the supercell approach are taken as input. The effect of using the GGA+U approach on the results is also reported. The properties of Co(3)O(4) are predicted with this method to compare to experiments and quasi-harmonic phonon calculations and are shown to achieve the accuracy necessary for CALPHAD modeling.     

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole: synthesis and reactivity

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline has been synthesized by reacting benzonitrile oxide with the enolate ion of methyl vinyl ketone. From 5-hydroxy-5-vinyl-2-isoxazoline, 5-vinylisoxazole was then quantitatively obtained by dehydration-aromatization under acidic conditions. Similar results, though not quantitative, were also found by treatment in 2-propanol under basic conditions (i-PrOH/H₂O, Na₂CO₃, reflux). In contrast to 2-propanol, reactions performed in methanol (and, in part, those carried out in ethanol) revealed a more complex behaviour, the nucleophilic addition of ROH onto the vinyl group being mainly observed. Nucleophilic addition was also found with alkyllithiums. The mechanism of the nucleophilic addition is discussed. Epoxidation and further reaction with benzonitrile oxide of both 3-hydroxy-5-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole are also described.     

MgO-P2O5和CaO-P2O5体系的热力学优化

基于严格评估的相图和热力学实验数据,采用相图计算方法对MgO-P₂O₅和CaO-P₂O₅体系进行热力学优化.液相采用修正的似化学模型进行描述,考虑了对近似处理液相中存在的短程有序.为了描述M₃(PO₄)₂(M = Mg, Ca)组分处的最大短程有序,将PO₄^3-当作液相中P₂O₅的基本组成单元.体系中所有的中间相都看作线性化合物并考虑了晶型转变.获得一套合理、可靠、自洽的模型参数用来描述体系中各相的热力学性质,在实验误差范围内很好地重现了相图、焓、熵和活度实验数据,为炼钢脱磷过程中熔渣体系热力学数据库的建立打下了坚实的基础.     

Polymorphism and photoluminescence properties of K3ErSi2O7

Two polymorphs of tripotassium erbium disilicate, K₃ErSi₂O₇, were synthesized by high‐temperature flux crystal growth during the exploration of the flux technique for growing new alkali rare‐earth elements (REE) containing silicates. Their crystal structures were determined by single‐crystal X‐ray diffraction analysis. One of them (denoted 1 ) crystallizes in the space group P6₃/mmc and is isostructural with disilicates K₃LuSi₂O₇, K₃ScSi₂O₇ and K₃YSi₂O₇, while the other (denoted 2 ) crystallizes in the space group P6₃/mcm and is isostructural with disilicates K₃NdSi₂O₇, K₃REESi₂O₇ (REE = Gd–Yb), K₃YSi₂O₇, K₃(Y_0.9Dy_0.1)Si₂O₇ and K₃SmSi₂O₇. In the crystal structure of polymorph 1 , the Er cations are in an almost perfect octahedral coordination, while in the crystal structure of polymorph 2 , part of the Er cations are in a slightly distorted octahedral coordination and the other part are in an ideal trigonal prismatic coordination environment. Sharing six corners, disilicate Si₂O₇ groups in the crystal structure of polymorph 1 link six ErO₆ octahedra, forming a three‐dimensional network and nine‐coordinated potassium cations are located in its holes. In the crystal structure of polymorph 2 , the disilicate Si₂O₇ groups connect four ErO₆ octahedra, as well as one ErO₆ trigonal prism. Three differently coordinated potassium cations are situated between them. Different site symmetries of the erbium cations in the crystal structures of polymorphs 1 and 2 affect their photoluminescence properties. Only polymorph 2 exhibits luminescence. Intense narrow lines in the emission spectrum are a result of the 4f–4f transition. The green emission line at 560 nm is the result of the Er³⁺ transition ⁴S_3/2→⁴I_15/2, and the luminescence line at 690 nm is the result of a ⁴F_9/2→⁴I_15/2 transition. The crystal morphologies of the two polymorphs are similar. Crystals of polymorph 1 are in the form of a hexagonal prism in combination with a hexagonal base, while crystals of polymorph 2 contain a dihexagonal prism in combination with a hexagonal base, although poorly developed faces of the dihexagonal pyramid can also be noticed.     

Synthesis and properties of 2-imino-3-benzyl-5-phenyl-1, 3, 4-oxadiazoline

2-Imino-3-benzyl-5-phenyl-1, 3, 4-oxadiazoline (Ia) was synthesized by the reaction of benzyl chloride with 2-amino-5-phenyl-1, 3, 4-oxadiazole (II). A number of imino-group derivatives of Ia were prepared. The structure of the compounds prepared were confirmed by means of their IR spectra.     

Structure and properties of 1-(2-pyridyl)-3-phenyl-5-arylformazans

A series of 1-(2-pyridyl)-3-phenyl-5-arylformazans, which form deeply colored complexes with Zn²⁺, Cu²⁺, Co²⁺, and Ni²⁺ salts, were obtained by coupling of arenediazonium salts, containing various substituants in the phenyl ring, with benzaldehyde 2-pyridylhydrazone. The presence of a nitro group causes deepening of the color and leads to the appearance of negative solvatochromism.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1379–1381, October, 1972.     

Ultraviolet spectra of 2-phenyl-4- and 2-phenyl-5-azaindan-1, 3-diones

The UV spectra of 2-phenyl-4-azaindan-1, 3-dione (I), 2-phenyl-5-azaindan-1, 3-dione (II), and their N-methylbetaines are investigated. 2×10^–5 M aqueous alcoholic solutions of 2-phenyl-4-azaindan-1, 3-dione (I) contain the anionic form (IA), and in solutions of 2-phenyl-5-azaindan-1, 3-dione (II) the betaine form (IIB) is also in equilibrium with the anion (IIA). Solutions of I and II in 0.1 M sulfuric acid are characterized by a wide and rather intense absorption band at about 500 m, indicating the presence of a betaine form (IB and IIB). In 2M hydrochloric acid solution 2-phenylazaindan-1, 3-diones and their N-methylbetaines (III and IV) are protonated at the oxygen atom, giving the enol forms of the N-protonated or corresponding N-methylated 2-phenylazaindandiones.     

Thermodynamic properties of DCl in D2O solution from 5 to 50°C

The themodynamic properties of solutions of deuterium chloride (DCl) in deuterium oxide (D₂O) have been determined from emf measurements of the electrochemical cell without transference from 5 to 50°C, and from 0.002 to 1.0 mol-kg^–1. The standard potential of the silver/silver chloride electrode relative to the platinum/deuterium electrode has been determined. An equation for the Gibbs energy as a function of temperature has been derived from which the enthalpy, entropy, and heat capacity have been computed. Equations for the activity coefficient and the osmotic coefficient of DCl in D₂O have been developed. The excess Gibbs energy of the solution and the excess partial molar free energy as a function of temperature have been calculated, from which the other excess thermodynamic properties have been computed. The values for the heat capacity and the apparent molar heat capacity have been compared with calorimetric data in the literature. The relative partial molar enthalpy has been calculated. The solvent isotope effect on the excess thermodynamic functions is discussed.     

Potentiometric and Thermodynamic Studies of 4-Sulfamethazineazo-3-methyl-1-phenyl-2- pyrazolin-5-one and Its Metal Complexes

Proton–ligand dissociation constants of 4-sulfamethazineazo-3-methyl-1-phenyl-2- pyrazolin-5-one (SMP) and metal–ligand stability constants of its complexes with bivalent metal ions (Mn²⁺, Co²⁺, Ni²⁺ , Cu²⁺, and Zn²⁺) have been determined potentiometrically in 0.1 M KCl, and a 40% (v/v) ethanol–water mixture. The order of the stability constants of the complexes was found to be Mn²⁺ < Co < Ni < Cu < Zn. The dissociation constants, pK ^H, of SMP and the stability constants, log K, of its complexes were determined at different temperatures and the corresponding thermodynamic parameters ( G, H, and S) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavorable. The formation of the complexes were found to be spontaneous, endothermic, and entropically favorable.     

Thermodynamic properties of Na2Ti6O13 and Na2Ti3O7: electrochemical and calorimetric determination

Standard values of Gibbs free energy, entropy, and enthalpy of Na₂Ti₆O₁₃ and Na₂Ti₃O₇ were determined by evaluating emf-measurements of thermodynamically defined solid state electrochemical cells based on a Na–β″-alumina electrolyte. The central part of the anodic half cell consisted of Na₂CO₃, while two appropriate coexisting phases of the ternary system Na–Ti–O are used as cathodic materials. The cell was placed in an atmosphere containing CO₂ and O₂. By combining the results of emf-measurements in the temperature range of 573⩽T/K⩽1023 and of adiabatic calorimetric measurements of the heat capacities in the low-temperature region 15⩽T/K⩽300, the thermodynamic data were determined for a wide temperature range of 15⩽T/K⩽1100. The standard molar enthalpy of formation and standard molar entropy at T=298.15 K as determined by emf-measurements are Δ_fH_m⁰=(−6277.9±6.5) kJ · mol⁻¹ and S_m⁰=(404.6±5.3) J · mol⁻¹ · K⁻¹ for Na₂Ti₆O₁₃ and Δ_fH_m⁰=(−3459.2±3.8) kJ · mol⁻¹ and S_m⁰=(227.8±3.7) J · mol⁻¹ · K⁻¹ for Na₂Ti₃O₇. The standard molar entropy at T=298.15 K obtained from low-temperature calorimetry is S_m⁰=399.7 J · mol⁻¹ · K⁻¹ and S_m⁰=229.4 J · mol⁻¹ · K⁻¹ for Na₂Ti₆O₁₃ and Na₂Ti₃O₇, respectively. The phase widths with respect to Na₂O content were studied by using a Na₂O-titration technique.     

Thermodynamic properties of silicate glasses and melts: IX. Bi2O3-SiO2 system

Differential high-temperature mass spectrometry was used to determine the activities of Bi₂O₃ in Bi₂O₃-SiO₂ glasses at 1000 K. The activities of SiO₂ and integral Gibbs energies in Bi₂O₃-SiO₂ glasses were determined. Negative deviations from the ideal behavior were revealed in the studied system at 1000 K.