Activity coefficients of NaCl in PEG 4000 + water mixtures at 288.15, 298.15 and 308.15 K

The electromotive force of the cell containing two ion-selective electrodes (ISE),

Na-ISE|NaCl (m), PEG ??4000 (Y), H₂O (100−Y)|Cl-ISE$\text{Na-ISE}|\text{NaCl}(m),\text{PEG}\text{\hspace{0.17em}??}4000(Y),{\text{H}}_2\text{O}(100-Y)|\text{Cl-ISE}$

Synthesis and characterization of the azido-bound five-coordinate high-spin iron(II) “picket fence” porphyrin complex

An Fe(II)-azido five-coordinate picket fence porphyrin complex with the formula [Na(2,2,2-crypt)][Fe^II(TpivPP)(N₃)] · 3C₆H₅Cl (TpivPP = α,α,α,α-tetrakis(o-pivalamidophenyl)porphinato, known as a picket fence porphyrin, and 2,2,2-crypt is the cryptand-222) has been synthesized and characterized. The synthesis utilizes cryptand-222 to solubilize sodium azide in the preparation procedure. The UV–Vis and IR spectroscopic data are consistent with an azido ferrous porphyrinate. The X-ray structural analysis and the Mössbauer results indicate that the ion complex [Fe^II(TpivPP)(N₃)]⁻ is high-spin and has the (d_xy)²(d_xz)¹(d_yz)¹(d_z2)¹(d_x2-y2)¹$({\text{d}}_{\mathit{xy}}{)}^2({\text{d}}_{\mathit{xz}}{)}^1({\text{d}}_{\mathit{yz}}{)}^1({\text{d}}_{z^2}{)}^1({\text{d}}_{x^2-y^2}{)}^1$ ground state electronic configuration.     

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.     

Ni(II) complexes of stereo-isomeric hexazamacrocyclic ligands derived from 2,6-diacetylpyridine

The nitrate and perchlorate Ni(II) complexes of the stereo-isomeric hexazamacrocyclic ligands L¹ (3,6,14,17,23,24-hexaazatricyclo[17.3.1.18,12]tetracosa-1(23),8,10,12(24),19,21-hexaene,2,7,13,18-tetramethyl) and L² (3,7,15,19,25,26-hexaazatricyclo[19.3.1.19,13]hexacosa-1(25),9,11,13(26),21,23-hexaene,2,8,14,20-tetramethyl) derived from 2,6-diacetylpyridine have been synthesized and characterized by microanalysis, LSI-MS, conductivity measurements, IR, UV–Vis spectroscopy and magnetic studies. Crystal structures of L¹·2H₂O as well as of the complexes [NiL¹](ClO₄₎₂$[{\text{NiL}}^1]({\text{ClO}}_4{)}_2$ and [NiL²](NO₃₎₂$[{\text{NiL}}^2]({\text{NO}}_3{)}_2$ have been determined. The X-ray studies show the presence of mononuclear endomacrocyclic complexes with the metal ion coordinated to all the nitrogen donor atoms from the macrocyclic framework in a N6 core. The geometry around the metal ions can be described as distorted octahedral. The nitrate and perchlorate anions do not coordinate to the metal ions, but they are involved in intermolecular interactions through hydrogen bonds to the amine groups of the macrocyclic ligands.     

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.