Thermodynamic characteristic of complex formation of some metals with 3-(4-chlorophenylazo)pentane-2,4-dione in aqueous ethanol

Effective charges of atoms in tautomeric forms (enol-azo, keto-azo, hydrazo) of 3-(4-chlorophenylazo) pentane-2,4-dione (L) have been determined by MO LCAO in the Hückel approximation. The complex formation of a series of metals with L in aqueous ethanol has been investigated by potentiometric and conductometric titration. Based on the results of potentiometric titration, the standard thermodynamic functions of complex formation have been established. They vary in the following order:

Interpolation of parameters of solutions expressed as functions of composition

The number of parameters in the polynomial is discussed for N components and a polynomial extending up to power n. This number is found to be but may be N less for relative thermodynamic functions. The equation of degree n for an N-component system requires the use of data for each of the i-component systems. Data on the n-component systems suffice if n相似文献   

Structure of products of the addition of methane- and ethane-sulfenyl chlorides to acrylic acid derivatives

Conclusions When alkanesulfenyl chlorides are added to acrylic derivatives CH₂=CHR (R=COOH, COOCH₃, COOCH₃ CN, CONH₂ a mixture of the isomers and is formed and the proportions of these depend on the nature of the substituent R.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1069–1075, June, 1966.     

Nonisothermal membrane phenomena across perfluorosulfonic acid-type membranes,Flemion S: Part II. Thermal membrane potential and transported entropy of ions

Thermal membrane potentials across the perfluorosulfonic acid-type membrane, Flemion S, were measured for HCl, alkali metal chlorides, and ammonium and methyl ammonium chlorides. The difference between the mean molar transported entropy of the counterions in the membrane and the partial molar entropy of the counterions in the external solution was determined from the experimental data on thermal membrane potential, thermoosmosis and electroosmosis. The sign of the thermal membrane potential in HCl solution varies from positive to negative with the concentration. In HCl and alkali metal chloride solutions, the order of their thermal membrane potentials (–/T) is H⁺>Li⁺=Na⁺>K⁺ which is roughly the inverse of that of the crystallographic radii of the ions. However, the order of their entropy differences is H⁺>Na⁺>K⁺>Li⁺ which is just the inverse of that of their thermoosmotic coefficients (D) or the entropy difference of water in thermoosmosis. For the ammonium and methyl ammonium ion forms, the orders of both –/T and increase with an increasing number of methyl groups: (CH₃)₄N⁺>(CH₃)₃NH⁺>(CH₃)₂NH ₂ ⁺ > CH₃NH ₃ ⁺ >NH ₄ ⁺ , which is also the inverse of that ofD or .     

Solvent extraction of rare earth metal ions with 1-(2-pyridylazo)-2-naphthol (PAN)

The solvent extraction of Yb(III) and Ho(III) by 1-(2-pyridylazo)-2-naphthol (PAN or HL) in carbon tetrachloride from aqueous-methanol phase has been studied as a function ofpH ^× and the concentration ofPAN or methanol (MeOH) in the organic phase. When the aqueous phase contains above ～25%v/v of methanol the synergistic effect was increased. The equation for the extraction reaction has been suggested as: $$\begin{gathered} Ln(H_2 0)_{m(p)}^{3 + } + 3 HL_{(o)} + t MeOH_{(o)} \mathop \rightleftharpoons \limits^{K_{ex} } \hfill \\ LnL_3 (MeOH)_{t(o)} + 3 H_{(p)}^ + + m H_2 0 \hfill \\ \end{gathered} $$ where:Ln ³⁺=Yb, Ho; $$\begin{gathered} t = 3 for C_{MeOH in.} \varepsilon \left( { \sim 25 - 50} \right)\% {\upsilon \mathord{\left/ {\vphantom {\upsilon \upsilon }} \right. \kern-\nulldelimiterspace} \upsilon }; \hfill \\ t = 0 for C_{MeOH in.} \varepsilon \left( { \sim 5 - 25} \right)\% {\upsilon \mathord{\left/ {\vphantom {\upsilon \upsilon }} \right. \kern-\nulldelimiterspace} \upsilon } \hfill \\ \end{gathered} $$ . The extraction equilibrium constants (K _ex ) and the two-phase stability constants (β ₃ ^× ) for theLnL ₃(MeOH)₃ complexes have been evaluated.     

Kinetic study of hydrogen peroxide reaction with hydroxonitrilotri(methylenephosphonato)iron(III) complex

The decomposition of hydrogen peroxide in the presence of hydroxonitrilotri(methylenephosphonato)iron(III), [Fe(NTMP)(OH)^4–], was studied in nitrate media (=0.10–0.26 M) over the 0.2–0.5 mM concentration range for the iron complex and the temperature range 26–40°C. The rate law;

The Second Dissociation Constant of Carbonic Acid in Ethanol–Water Mixtures from 5 to 45°C

The determination of the second dissociation constant of carbonic acid K ₂ in 5, 15, and 25 mass% ethanol—water mixed solvents has been made using cell of the type:

Enzymatic mechanisms and electron transfer mediation in chronoamperometric biosensors

Electron transfer mediation to an anode, whose potential is judiciously controlled, provides the conceptual basis for the development of novel chronoamperometric biosensors. The mediators are appropriately selected redox couples (Ox/Red) which are amenable to recycling in the following type of enzyme E catalyzed reaction sequence

Kinetics and mechanism of oxidation of the chromium(III)-DL-aspartic acid complex/periodate reaction. Evidence for iron(II) catalysis

The kinetics of oxidation of the chromium(III)-DL- aspartic acid complex, [CrIIIHL]+ by periodate have been investigated in aqueous medium. In the presence of Fe^II as a catalyst, the following rate law is obeyed:

Die Kristallstruktur des Chromarsenids Cr4As3

The crystal structure of Cr₄As₃ has been determined by single crystal photographs: $$\begin{gathered} space group Cm - C_s ^3 \hfill \\ \alpha = 13.16_8 {\AA} \hfill \\ b = 3.54_2 {\AA} \hfill \\ c = 9.30_2 {\AA} \hfill \\ \beta = 102.1_9 \circ \hfill \\ \end{gathered}$$ Cr₄As₃ crystallizes with a novel structure type, which can be derived from the MnP-structure type.     

Berechnung der Madelungkonstante von Aragonit

Madelung's coefficientM _a of aragonite has been calculated considering the non-spherical shape of the CO ₃ ^2? -ions. As a result of the multipole expansionM _a has been found as a function of the C?O-distanced and the charge on the oxygen atomq _o to:

$$\begin{gathered} M_a = \frac{1}{4}\left\{ {10,4446---\left[ {0,65849 + \sum\limits_{n = 1}^{10} {A_n \left( {\frac{{d---0,8}}{a}} \right)^n } } \right]} \right\} \cdot q_o \hfill \\ \left. \begin{gathered} \hfill \\ ---\left[ {0,11066 + \sum\limits_{n = 1}^{12} {B_n \left( {\frac{{d---0,8}}{a}} \right)} ^n } \right] \cdot q_o^2 \hfill \\ \end{gathered} \right\}. \hfill \\ \end{gathered}$$     

Atranes

A method of synthesizing hitherto unknown 1-aroxysilatranes (R=aryl) is worked out. It is based on transesterification of lower tetraalkoxysilanes with an equimolecular mixture of triethanolamine and the appropriate phenol (naphthol). Using the method, 12 compounds of the indicated type have been prepared and characterized, the yields in the main exceeding 90%.For Part VII see [1].     

Atranes

Complexes of ferratrane-3,7,10-trione (I) of the composition I · H₂O, I · H₂O₂, I · OS(CH₃)₂, and I · 2OS(CH₃)₂ were synthesized. The IR spectra and derivatograms of these compounds were studied.See [1] for communication XXXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 164–170, February, 1973.     

Kinetics and mechanism of oxidation of hydroxylamine by tetrachloroaurate(III) ion

The oxidation of H₂NOH is first-order both in [NH₃OH⁺] and [AuCl₄ ^–]. The rate is increased by the increase in [Cl^–] and decreased with increase in [H⁺]. The stoichiometry ratio, [NH₃OH⁺]/[AuCl₄ ^–], is 1. The mechanism consists of the following reactions.

Iodine Hydrolysis Equilibrium

The equilibrium constant for the hydrolytic disproportionation of I₂

0-aminophenol and 8-hydroxyquinoline as ligands of Cu(II) in 1M-Na(ClO4) at 25°C

The complex formation between Cu(II) and 8-hydroxyquinolinat (Ox) was studied with the liquid-liquid distribution method, between 1M-Na(ClO₄) and CHCl₃ at 25°C. The experimental data were explained by the equilibria: $$\begin{gathered} \operatorname{Cu} ^{2 + } + Ox \rightleftharpoons \operatorname{Cu} Ox \log \beta _1 = 12.38 \pm 0.13 \hfill \\ \operatorname{Cu} ^{2 + } + 2 Ox \rightleftharpoons \operatorname{Cu} Ox_2 \log \beta _2 = 23.80 \pm 0.10 \hfill \\ \operatorname{Cu} Ox_{2aq} \rightleftharpoons \operatorname{Cu} Ox_{2\operatorname{org} } \log \lambda = 2.06 \pm 0.08 \hfill \\ \end{gathered} $$ The equilibria between Cu(II) and o-aminophenolate (AF) were studied potentiometrically with a glass electrode at 25°C and in 1M-Na(ClO₄). The experimental data were explained by the equilibria: $$\begin{gathered} \operatorname{Cu} ^{2 + } + AF \rightleftharpoons \operatorname{Cu} AF \log \beta _1 = 8.08 \pm 0.08 \hfill \\ \operatorname{Cu} ^{2 + } + 2AF \rightleftharpoons \operatorname{Cu} AF_2 \log \beta _2 = 14.60 \pm 0.06 \hfill \\ \end{gathered} $$ The protonation constants ofAF and the distribution constants between CHCl₃?H₂O and (C₂H₅)₂O?H₂O were also determined.     

A biomonitoring study: 210Po and heavy metals in marine organisms from the Adriatic Sea (Italy)

In various samples of marine organisms from the central Adriatic Sea ²¹⁰Po was determined by alpha spectrometry and thirteen heavy metals (Mn, Fe, Co, Cr, V, Ni, Cu, Zn, Cd, As, Sn, Hg and Pb) by energy dispersive, polarised X ray fluorescence spectrometry (EDPXRF). ²¹⁰Po activity concentration ranged between 0.3 and 44.6 Bq kg⁻¹ fresh weight. The data obtained depend upon the type of the marine organism; among the pelagic species, anchovy displayed the highest polonium concentration. Typical concentration ( \upmu \textg·\textg_(\textfresh) ^{- 1} ) \left( {\upmu {\text{g}}\cdot{\text{g}}_{{({\text{fresh}})}}^{ - 1} } \right) ranges were as follows: Mn: <1.32–1.73; Fe: 4.11–94.27; Co < 0.13–0.23; Ni: <0.13–0.52; Cu: 0.37–145.31; Zn: 0.46–16.46; Cd: <0.10–0.25; As: 0.36–60.52; Hg: <0.13–0.70; Pb: <0.13–0.35, Sn: <0.20–12.67; V and Cr were always <1.32. The data obtained are also compared with those obtained by other authors for the same organism coming from other Italian seas.     

Thermal properties of Na2TeO4(s) and TiTe3O8(s)

Molar heat capacity measurement on Na₂TeO₄(s) and TiTe₃O₈(s) were carried out using differential scanning calorimeter. The molar heat capacity values were least squares analyzed and the dependence of molar heat capacity with temperature for Na₂TeO₄(s) and TiTe₃O₈(s) can be given as, $$ \begin{gathered} {\text{C}}^{\text{o}}_{{{\text{p}},{\text{m}}}} \left\{ {{\text{Na}}_{ 2} {\text{TeO}}_{ 4} \left( {\text{s}} \right)} \right\} \,={159}.17 { } + 1.2\,\times\,10^{-4}T-{55}.34\,\times\,10^{5}/T^{2};\hfill \\ C^{\text{o}}_{{{\text{p}},{\text{m}}}} \left\{ {{\text{TiTe}}_{ 3} {\text{O}}_{ 8} \left( {\text{s}} \right)} \right\}\,=\,{ 275}.22{ }+{4}.0\,\times\, 10^{-5}T-{58}.28\,\times\,10^{5}/T^{2};\hfill \\ \end{gathered} $$ From this data, other thermodynamic functions were evaluated.     

Thermische Umlagerung von Acetoxy-cyclohexadienonen, 2. Mitt.

Zusammenfassung Es wird die Frage untersucht, ob bei der thermischen Umlagerung von entsprechend allyl-substituierten o-Benzochinol-acetaten der Allyl- oder der Acetoxylrest rascher wandert. Das 2-Allyl-2-acetoxy-cyclohexadienon liefert bei der genannten Reaktion (es sind schon Temperaturen um 100° ausreichend) überwiegend ein Monoacetat des 4-Allylbrenzcatechins. Damit ist bewiesen, daß der Rest rascher als der Rest in die p-Stellung zur Carbonylgruppe des Chinolacetates wandert. Eine Wanderung des Acetoxylrestes in die o- oder in die p-Stellung zur Carbonylgruppe, welche zur Bildung von 3-Allyl-brenzcatechin bzw. 2-Allylhydrochinon führen müßte, konnte nicht beobachtet werden. Entsprechend liefert das 2,6-Diallyl-2-acetoxy-cyclohexadienon bei der thermischen Umlagerung überwiegend ein Monoacetat des 3,5-Diallyl-brenzcatechins. Nach einem anderen Mechanismus verläuft die Umlagerung des 2-Methyl-6-allyl-2-acetoxy-cyclohexadienons. Es entsteht neben wenig 2-Methyl-6-allyl-hydrochinon in der Hauptmenge ein Monoacetat des 3-Methyl-5-allyl-brenzcatechins. Es wird also die Allylgruppe durch den in die o-Stellung wandernden Acetoxylrest verdrängt. Auf diese Reaktion wird näher eingegangen, weil sie in engem Zusammenhang mit der Frage steht, ob ganz allgemein eine Umlagerung von o-Chinolacetaten vom Typ in die Isomeren möglich ist.Mit 2 AbbildungenHerrn Prof. Dr.F. Feigl zum 70. Geburtstag in alter Freundschaft!F. W. E. Zbiral, F. Wessely undE. Lahrmann, (gilt als 1. Mitt. dieser Reihe), Mh. Chem.91, 331 (1960).