Standard molar Gibbs free energy of formation of Pb5CrO8(s), Pb2CrO5(s), and PbCrO4(s)

Standard molar Gibbs free energy of formation of ternary oxides Pb₅CrO₈(s), Pb₂CrO₅(s), and PbCrO₄(s) were determined by measuring equilibrium oxygen partial pressures over relevant phase fields using manometry and solid oxide electrolyte based emf methods and are given by: ${\mathrm{\Delta }}_f{G}_m^{°}{\text{Pb}}_5{\text{CrO}}_8(s)\pm 0.55/(\text{kJ}·{\text{mol}}^{-1})=-1809.4+0.6845(T/\text{K})(837\le T/\text{K}\le 1008)\text{,}$${\mathrm{\Delta }}_f{G}_m^{°}{\text{Pb}}_2{\text{CrO}}_5(\text{s})\pm 0.30/(\text{kJ}·{\text{mol}}^{-1})=-1161.3+0.4059(T/\text{K})(859\le T/\text{K}\le 1021)\text{,}$${\mathrm{\Delta }}_{\text{f}}{G}_m^{°}{\text{PbCrO}}_4(\text{s})\pm 0.17/(\text{kJ}·{\text{mol}}^{-1})=-909.8+0.3111(T/\text{K})(863\le T/\text{K}\le 1093)\text{,}$     

2-Pyridyloximate clusters of cobalt and nickel

The use of 2-pyridyloximate(-1) ligands, (py)C(R)NO⁻ [R = H, Ph, 2-pyridyl (py)] in cobalt and nickel(II) chemistry has been investigated and led to four families of clusters. A representative member of each family, namely $[{\mathrm{Co}}^{\text{II}}{\mathrm{Co}}_2^{\text{III}}\{(\mathrm{py})\mathrm{C}(\mathrm{ph})\text{NO}{\}}_6]({\mathrm{PF}}_6{)}_2$ (1), $[{\mathrm{Co}}_2^{\text{II}}{\mathrm{Co}}_2^{\mathrm{III}}(\mathrm{OH}{)}_2({\mathrm{O}}_2\mathrm{CMe}{)}_2\{(\mathrm{py}{)}_2\mathrm{CNO}{\}}_4(\mathrm{MeOH}{)}_2]({\mathrm{ClO}}_4{)}_2$ (2), [Ni₉(OH)₄{(py)CHNO}₁₀(H₂O)₈]{N(CN)₂}₃(ClO₄) [3{N(CN)₂}₃(ClO₄)] and [Ni₄(O₂CMe)₄{(py)C(ph)NO}₄(MeOH)₂] (4) is briefly structurally and magnetically described.     

The relationship between vapour pressure,vaporization enthalpy,and enthalpy of transfer from solution to gas: An extension of the Martin equation

Martin’s equation, ${\mathrm{\Delta }}_{\text{sln}}^{\text{g}}G={\mathrm{\Delta }}_{\text{sln}}^{\text{g}}{G}_{\text{o}}+z{\delta }_{\text{sln}}^{\text{g}}G$, is extended to cover vaporization free energy $({\mathrm{\Delta }}_{\text{l}}^{\text{g}}G)$. The extended equation is further expanded in terms of enthalpy and entropy and then used to correlate vaporization enthalpy $({\mathrm{\Delta }}_{\text{l}}^{\text{g}}H)$ and enthalpy of transfer from solution to gas $({\mathrm{\Delta }}_{\text{sln}}^{\text{g}}H)$. Data available in the literatures are used to validate and support the speculations derived from the proposed equation.     

Partial molar volumes of organic solutes in water. XX. Glycine(aq) and l-alanine(aq) at temperatures (298 to 443) K and at pressures up to 30 MPa

Density data for dilute aqueous solutions of two amino acids (glycine, l-alanine) obtained using a flow vibrating-tube densimeter are presented together with partial molar volumes at infinite dilution (standard molar volumes, $V_{\text{m,}2}^{°}$) calculated from the measured data. The experiments were performed at temperatures from (298 up to 443) K at pressures close to the saturation line of water, at pressures in the range from (15 to 17) MPa, and at 30 MPa. Values of an analogue of isothermal compressibility, ${\kappa }_{T\text{,}2}^{°}=-(1/V_{\text{m,}2}^{°})(?V_{\text{m,}2}^{°}/?p{)}_T$, are also evaluated. Maxima on the curves $V_{\text{m,}2}^{°}(T)$ and ${\kappa }_{T\text{,}2}^{°}(T)$ are observed and discussed. The new data along with literature values of standard molar volumes and heat capacities are used for generating the recommended parameterization of an equation of state for standard molar thermodynamic properties of the aqueous amino acids.     

Dioxygen affinities and catalytic oxidation performance of cobalt（Ⅱ） hydroxamates with benzo-15-crown-5 pendants

The oxygenation constants(Ko_2)of cobalt(Ⅱ)hydroxamates(CoL_2~1-CoL_2~3)with benzo-15-crown-5(B15C5)pendants were measured over the range of-5 to 20℃,and the values of thermodynamic parameters(ΔH~0 andΔS~0)were calculated based on these(No_2)values.Meanwhile,these crowned complexes were employed to the oxidation for p-xylene to p-toluic acid with air at 110Δunder normal atmospheric pressure.The effects of B15C5 pendant and the length of chain bonded to B15C5 in these complexes on the O_2-binding capabilities and oxidation for p-xylene were investigated with the comparison of crown-free analogues CoL_2~4.     

Thermodynamic properties of CaTiF5(s)

Calcium titanofluoride CaTiF₅(s) was prepared by solid-state reaction of CaF₂(s) with TiF₃(s) and characterized by X-ray diffraction method. The standard molar isobaric heat capacity $(C_{p\text{,m}}^{\circ })$ of CaTiF₅(s) was determined by a power compensated differential scanning calorimeter in the temperature from 230 K to 710 K. A solid-state galvanic cell with CaF₂ as electrolyte was used to determine the standard molar Gibbs energy of formation $({\mathrm{\Delta }}_{\text{f}}{G}_{\text{m}}^{\circ })$ of CaTiF₅ in the temperature range from 803 K to 1005 K. The galvanic cell can be depicted as:$(-)\text{Pt,}{\text{O}}_2(\text{g,}101.325\text{kPa})/\{\text{CaO(s)}+{\text{CaF}}_2(\text{s})\}//{\text{CaF}}_2//\{{\text{CaTiF}}_5(\text{s})+{\text{CaTiO}}_3(\text{s})\}/{\text{O}}_2(\text{g,}101.325\text{kPa})\text{,Pt}(+)$The second law analysis of present data were carried out to derive the standard entropy $S_{\text{m}}^{\circ }(298.15\text{K})$ and the enthalpy of formation ${\mathrm{\Delta }}_{\text{f}}{H}_{\text{m}}^{\circ }(298.15\text{K})$ and the values derived are 68.7 J · K⁻¹ · mol⁻¹ and −2848.4 kJ · mol⁻¹, respectively.