The nature of the splitting of the bands in the infrared spectra of phosphorus dithioacids

Conclusions The IR spectra of a series of phosphorus dithioacids were studied under different conditions. The splitting of bands in the regions 490–550 and 2500–2600 cm^–1 is explained by rotational isomerism.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 672–673, March, 1968.     

The effect of high pressure on the ion pair equilibrium constant of alkali metal fluorides: A spectrophotometric study

Bromophenol blue indicator was used in UV-visible spectrophotometric measurements to study ion association constants of alkali metal fluorides. The equilibrium constants for the ion pair formation of the alkali metal fluorides were determined as a function of ionic strength at one atmosphere pressure and 25°C. The effect of pressure on these association constants was measured at a constant total ionic strength of 1.0 mol-kg^–1 over a pressure range of 1 to 2000 atmospheres at 25°C. The pressure dependences of the stoichiometric association constants of the alkali metal fluorides are given by: lnK _LiF ^* =0.77–2.47×10^–4P–2.12×10^–8P²; lnK _NaF ^* =0.53–1.08×10^–4P–1.66×10^–8P²; lnK _KF ^* =0.24–4.41×10^–5P–7.15×10^–8P²; lnK _RbF ^* =–0.17–8.65×10^–5P–4.51×10^–8P²; and lnK _CsF ^* = –0.37–1.14×10^–4P–6.82×10^–8P², where P is the pressure in atmospheres. The stoichiometric molar volume and compressibility changes for ion pair formation of the alkali metal fluorides were evaluated from the pressure dependence of K _MF ^* data. The thermodynamic association constants were also calculated making use of activity coefficient data from the Pitzer equations. The partial molal volume and compressibility changes for ion pair formation of each alkali metal fluoride are reported.     

The lipid composition of the Western Mediterranean aerosol

Summary Marine remote aerosol samples collected in a fixed station situated at 1100 m above sea level in Mallorca Island (Western Mediterranean) have been analyzed for lipids, both neutral and acidic, by capillary gas chromatography (GC) and GC coupled to mass spectrometry. Higher plant and algal compounds are predominant. The former encompass distributions of even numbered C22–C32 n-alkan-1-ols (8–21 ng/m³) and n-aldehydes, C25–C32 odd numbered n-alkanes (3–6 ng/m³), and n-nonacosan-10-ol, -sitosterol (0–0.09 ng/m³), dehydroabietic acid and triterpenols. The latter are constituted by even numbered C14–C18 fatty acids (0.6–30 ng/m³) and cholest-5-en-3-ol (0–0.86 ng/m³). Pyrolytic polycyclic aromatic hydrocarbons are also found (86–410 pg/m³) whereas direct petrogenic inputs are not significant.     

The origin of the two νCO bands in the infrared spectra of acetophosphides

Conclusions The two intense bands in the infrared spectra of acetophosphides at 1600–1800 cm^–1 are due to valence vibrations of the carbonyl group of the cis-and transisomers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 188–190, January, 1968.     

The kinetics of the dissolution of monoclinic pyrrhotite in aqueous acidic solutions

Using the rotating disc method, the rates of dissolution of natural monoclinic pyrrhotite, FeS_1.14, in oxygen-free aqueous solutionsS([H⁺]=0.1, [Na⁺]=0.9, [ClO ₄ ^– ]=1.0 mol kg^–1) were determined. In the temperature range 40–90 °C the dissolution reaction occurs under kinetic control; the activation energy being 14±1 kcal mol^–1 (50±5 kJ mol^–1).

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Die Kinetik der Auflösung von monoklinem Pyrrhotin in sauren wäßrigen Lösungen

Zusammenfassung Die Auflösungsgeschwindigkeit von natürlichem monoklinen Pyrrhotin, FeS_1.14, wurde in sauerstofffreien LösungenS([H⁺]=0.1, [Na⁺]=0.9, [ClO ₄ ^– ]=1.0 mol kg^–1) mit Hilfe der Methode der rotierenden Scheibe bestimmt. Im Temperaturbereich von 40–90° erfolgt die Auflösungsreaktion kinetisch kontrolliert, wobei eine Aktivierungsenergie von 14±1 kcal mol^–1 (59±5 kJ mol^–1) gefunden wurde.

     

The effect of pressure on the dissociation constant of hydrofluoric acid and the association constant of the NaF ion pair at 25°C

The effect of pressure on the dissociation constant of hydrofluoric acid was determined by using the indicator technique at 25°C at an ionic strength of 0.1m over a pressure range of 1 to 2000 atm. A value of 3.14 for pK _a ^* at I =0 was obtained by extrapolation to zero ionic strength at 1 atm. The pressure dependence yielded a partial molar volume change of –9.6 cm³-mol^–1 and a compressibility change of — 35×10^–3 cm³-mol^–1 –atm^–1 for the dissociation. The dependence of ionic strength on the association constant K _A ^* of NaF was studied at 25°C and 1 atm. Extrapolation to I=0 yielded a pK _A ^* of –0.78. The pressure dependence of K _A ^* gave a change of volume of 3.26 cm³-mol^–1 and a change in compressibility of 6×10^–3 cm³-mol^–1-atm^–1 for the formation of the ion pair.     

The Solvent Effect on the Rate of Reaction between Propanethiol and Chlorine Dioxide

The products and kinetics of the liquid-phase oxidation of propanethiol by chlorine dioxide in organic media (n-heptane, 1,4-dioxane, carbon tetrachloride, benzene, diethyl ether, ethyl acetate, acetone, and acetonitrile) at temperatures from –10 to 70°C were examined. The reaction rate constants and activation parameters were measured in the above solvents. A strong solvent effect on the reaction kinetics was found (k= 1.67 × 10^–3or 52.7 l mol^–1s^–1(25°C) in heptane or acetonitrile, respectively). The data were analyzed in terms of the Leydler–Eyring and Koppel–Palm equations. The formation of high-polarity intermediates in the test reaction was suggested.     

The fractionation of the polysaccharides of rice grain starch

Summary It has been shown that on centrifugation in a linear cesium chloride gradient the amylose and amylopectin of rice starch are concentrated in the density zones of 1.00–1.15 g/cm³ and 1.65–1.76 g/cm², respectively.Translated from Khimiya-Prirodnykh Soedinenii, No. 6, pp. 692–694, November-December, 1978.Original article submitted July 18, 1978.     

The seed oil of Catalpa. I

Summary 1. The fatty-acid compositions of the seed oils of catalpas cultivated in the Soviet Union have been studied.2. The oil content of the seeds is 21.2–36.7%, the refractive index 1.4905–1.5400, and the iodine number 184.8–201.7.3. The following fatty acids have been found in catalpa oil (%): palmitic — 1.3–4.3; stearic — 1.1–2.5; heneicosanoic — 0.5–5.2; oleic — 5.5–9.8; linoleic — 39.6–50.3; linolenic — 0.4–1.8; and eleostearic — 32.8–46.2.4. The most accurate results for characterizing the degree of unsaturation of the fatty acids of the catalpa seed oils are given by Woburn's method of determining iodine numbers. The iodine numbers obtained experimentally agree with those calculated and consequently the addition of halogen to the system of double bonds takes place at all the double bonds.5. The degree of unsaturation of the fatty acids of catalpa oil characterized by the iodine numbers and refractive indices increases in the sequence of species southern, northern, teas, Chinese and has a tendency to rise on passing to more northerly zones, which is one more piece of evidence confirming the correctness of S. L. Ivanov's climatic theory of the structure of fats.Kalinin Polytechnic Institute. Moscow Branch of the All-Union Scientific-Research Institute of Fats. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 331–337, May–June, 1977.     

The Plausible Aromaticity of 1,8-Naphthalimides: The Enthalpy of Formation of N-Methyl-1,8-Naphthalimide

In order to understand the aromaticity of 1,8-naphthalimides, the enthalpies of combustion and sublimation of N-methyl-1,8-naphthalimide were determined. The numerical values are –6095.8 ± 3.5 and 109.7 ± 0.8 kJ · mol^–1. The enthalpies of formation of condensed and gas phase N-methyl-1,8-naphthalimide are accordingly –306.1 ± 3.9 and –196.4 ± 4.0 kJ · mol^–1. It is deduced that naphthalimides enjoy some 40 kJ · mol^–1 of aromatic stabilization over that of the maleimides, shown to be nominally destabilized and modestly antiaromatic in our recently published thermochemical study.     

The polybuffer separation of the alkaloids of Vinca erecta

Summary By separating the total alkaloids ofV.erecta according to their basicities in an APS, in addition to bases known previously we have isolated ervincidine, apovincamine, (+)-quebrachamine, dl-eburnamine, (–)-1,2-dehydroaspidospermidine, and kopsanone. This is the first time that these alkaloids have been obtained from this plant. Thin-layer chromatography showed the presence of another 10–12 uncharacterized alkaloids.The region of the passage into the buffer solutions of some alkaloids has also been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 713–717, November–December, 1970.     

The EDTA complexes of astatine

Using the electromigration method the monopositive astatine ion has been shown to form EDTA [H₄L] complexes in 0.1M NaClO₄ solution at pH=3–10. The ion mobility of the AtL^3– complex is 5.60/23/x10^–4 cm².V^–1.s^–1.     

The adsorption of liquid water on the surface of quartz

Conclusions Liquid water has positive adsorption on the surface of quartz; the value of the specific adsorption decreases with increasing temperature, comprising 9·10^–10 g/cm² at 0° and 4·10^–10 g/cm² at 70°.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1276–1280, June, 1972.     

The kinetics of the reaction of iodine with hydrazine as studied by pulse radiolysis

Pulse radiolysis was utilized to study the iodine — hydrazine reaction in aqueous solutions of pH3 to 7, at I^– concentrations of 0.02 to 0.34M, and a constant ionic strength of 0.35M. The reaction rate was found to be proportional to [H⁺]^–1 and [I^–]^–1. Experimental results support the assumption that the rate-determining step is the reaction of I₂ with N₂H₄ with a rate constant K1.2×10⁷ M^–1s^–1.     

The effect of pyridine bases and transition-metal oxides on the activity of PdCl2 in the carbonylation of aromatic mononitro compounds by carbon monoxide

Conclusions Palladium chloride which is a catalyst for the preparation of phenylisocyanates by the carbonylation of nitro compounds is promoted by pyridine and its homologs and also by transition-metal oxides, which provide for the conversion of nitro compounds into phenyl-, methylphenyl-, and chlorophenylisocyanates in 75–92% yield and 84–97% selectivity at 200°C and 50–100 atm CO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 585–589, March, 1979.     

The unusual influence of the acidity of the medium on the rate of isotopic exchange of hydrogen of C6H6Cr(CO)2P(C6H5)3

Conclusions When the acidity function H₀ is varied from +1 to –2.5, the rate of the isotopic exchange of hydrogen of benzenechromiumdicarbonylphenylphosphine is directly proportional to the acidity of the medium, while in the case of higher acidities from –2.5 to –7.1, an inverse dependence is observed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 756–758, April, 1974.     

Towards the understanding of the spectroscopic behaviour of the C–H oscillator in C–HO hydrogen bonds: the effect of solvent polarity

The effect of solvent polarity versus specific C–HO contacts on the vibrational νC–H mode is studied using CHCl₃ as a model system. Ab initio SCI–PCM calculations show that the overall shift of the νC–H band, sometimes ascribed to the C–HO hydrogen bonding, can in fact be explained by the electrostatic interaction with a dielectric environment. The presence of a new νC–H band – assigned to the C–HO bonded forms – remains as the most reliable evidence of C–HO hydrogen bonding.     

The technological and economic management of the environmental variable in the pharmaceutical–chemical industry

Industrial risks increate with technological progress. The study of potential risks is routine in the pharmaceutical–chemical industry. Here, like in other industrial activities, a risk coefficient is introduced that varies within space time limits.A control system of environmental safety and health monitoring processes should be based on the data obtained from Hazard and Operability Studies (HAZOP).The space variable influences the chemical risk coefficient that applies to the whole the production cycle (including waste recycling). For the sake of prevention, many enterprises have adopted the integrated management system, which is now moving to an additional required feature: environment and health protection and safety assurance inside and outside the industrial area (in compliance with UNI, ISO 14000 and OHSAS 18001standards).Our goal is to examine the technological–scientific–environmental changes in the pharmaceutical–chemical sector in order to asses the new extent of chemical regarding management systems.This will entail a cultural change that will call for the necessary economic strategies for industries to implement the appropriate environmental–technological programs.     

The oxidation of organic compounds

In a study of the behavior of tris(hydroxymethyl)-4-picoline (I) under the conditions of vapor-phase oxidation on a vanadium-tin oxide catalyst, it was found that with the addition of 150–250 mole of water and 125–200 mole of O₂ per mole of I and a contact time of 0.35–0.45 sec, the main reaction product was isonicotinic acid (II), the yield of which amounted to 60–65% of theoretical, calculated on the I passed.For part XLVIII, see [1].