摘要:

The23Na chemical shifts, extrapolated to infinite dilution, of solutions containing sodium iodide dissolved in 14 different oxygen or nitrogen donor organic solvents have been determined. The observed range of chemical shifts can be successfully related to changes in the paramagnetic term of the general nuclear screening equation. A fair correlation between the magnitude of the paramagnetic term and the Lewis basicity of the solvent has been drawn. Those solvents showing anomalous behavior are the ones for which large magnetic anisotropies are to be expected. The23Na chemical shifts for two mixed solvent systems containing sodium iodide have been obtained, and these support the conclusion that preferential solvation of the sodium ion occurs.

ISSN:0008-4042    

DOI:10.1139/v68-569

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The kinetics of the formation of Mn(III) hematoporphyrin in glacial acetic acid has been studied spectrophotometrically.On addition of Mn(II) to porphyrin in glacial acetic acid a species which appears to be the monocation immediately is formed and is then converted to Mn(III) hematoporphyrin at a rate suitable for kinetic studies.The rates of reaction were measured at 45, 50, and 55 °C and the activation energies were calculated.

ISSN:0008-4042    

DOI:10.1139/v68-570

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The kinetics of the electrochemical oxidation of silver to Ag2O in NaOH have been studied at different temperatures and hydroxyl ion concentrations. The enthalpy of activation was found to be ~ 5 kcal/mole. The kinetics of oxidation of Ag2O to AgO are discussed.

ISSN:0008-4042    

DOI:10.1139/v68-571

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Some anhydrous transition metal acetates (Mn(II), Co(II), Cu(II), Ni(II), Zn(II), Ag(I), Mo(II), Ce(III), La(III)) have been prepared and their infrared spectra measured in the solid state. The infrared spectra have been related to established modes of bonding of the acetate group to metals. Thermal decompositions of the anhydrous acetates have been investigated by thermogravimetric analysis; magnetic moments and visible spectra have been measured.

ISSN:0008-4042    

DOI:10.1139/v68-572

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The enthalpies of reaction of crystalline magnesium oxide in aqueous hydrogen bromide and iodide solutions have been determined. The enthalpies of precipitation of magnesium, calcium, and strontium fluorides and the enthalpies of solution of magnesium iodide and bromide have also been determined and the following data are derived: ΔHf0(298 °K) of MgBr2(c), MgI2(c), CaF2(c), NaMgF3(c), SrF2(c) are −125.3 ± 0.4, −88.1 + 0.35, −291.9 ± 0.2, −406.7 ± 0.3, −291.2 ± 0.3 kcal mole−1respectively. NaMgF3is an ideal mixed crystal.

ISSN:0008-4042    

DOI:10.1139/v68-573

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Ferrocenylethylenes are readily synthesized from acylferrocenes and the appropriate triphenylphosphorane in dimethylsulfoxide. Details of the nuclear magnetic resonance spectra of 12 ethylenes have been recorded.

ISSN:0008-4042    

DOI:10.1139/v68-574

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The spectra of trivalent Ce, Pr, Nd, Sm, Eu, Tb, Dy, Tm, and Yb ions in molten LiCl–KCl at 450 °C are reported over the range 0.28 to 2.8 μ and the baricenters of terms are tabulated for a wide variety of crystal and liquid hosts. These hosts can be arranged in a nephelauxetic series and for Pr3+actual nephelauxetic parameters, β, can be calculated by comparing average multiplet energies.

ISSN:0008-4042    

DOI:10.1139/v68-575

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The crystal structures of the spinels Co3O4, NiCo2O4, Co3S4, and NiCo2S4were refined from X-ray and neutron powder data. Their lattice parameters at room temperature and the positional parameters of the oxygen and sulfur atoms were: Co3O4, 8.0835 ± 6 Å, 0.2640 ± 8; NiCo2O4, 8.114 ± 14 Å, 0.2583 ± 34; Co3S4, 9.4055 ± 12 Å, 0.2591 ± 5; NiCo2S4, 9.3872 ± 7 Å, 0.2591 ± 3. The thermal stabilities of the two oxides in air and in oxygen at 1 atm were investigated by thermogravimetric analysis and differential thermal analysis, and the magnetization of NiCo2O4was measured down to 4.2 °K in fields up to 11.70 kOe. From neutron diffraction NiCo2O4. was found to be inverse, while NiCo2S4was shown to be normal. The results of the magnetization measurements and the neutron-diffraction patterns at 111 and 393 °K were found to be equally consistent with the magnetic structure proposed for NiCo2O4by Blasse, Co2+[Ni3+Co3+]O4(Co2+in a high-spin and Ni3+andCo3+in low-spin states), and with Co3+[Ni2+Co3+]O4(Co3+in 8(a) in a high-spin and Co3+in 16(d) in a low-spin state). The sublattice magnetizations were not completely aligned even at 4.2 °K; the net magnetic moment derived from the magnetization measurements was only 1.25 μB, which is lower than the value of 2 μBexpected from either model. At 111 °K the moments of the ions in the tetrahedral and octahedral sites were estimated to be 1.9 ± 0.2 and −0.5 ± 0.1 bohr magnetons respectively.

ISSN:0008-4042    

DOI:10.1139/v68-576

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The velocity of sound was measured with a precision of 0.1% in liquid krypton and xenon at pressures between the vapor pressure and about 65 atm, from near their triple points to near their critical points.A corresponding states treatment of these measurements and previous results in argon showed that, with a suitable choice of relative molecular parameters (σ,ϵ), theW*(P*,T*) surfaces were coincident to within the experimental error, except for argon near the critical temperature.The relative values of the effective atomic radii σ obtained from this analysis were somewhat lower than those obtained from other thermodynamic properties.

ISSN:0008-4042    

DOI:10.1139/v68-577

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The reactions of the fluorocarbon olefins, C2F4, C3F6, and C4F8-2, with active nitrogen were studied in a flow system. The active nitrogen was produced by a microwave discharge at a concentration of 2.1 × 10−6 mole/s. The major gaseous products of the reactions are fluorocarbons and their production was studied quantitatively at the temperatures 25, 250, and 400 °C and at a large number of reactant flow rates to a maximum of approximately 3 × 10−6 mole/s.Three nitrogen-containing compounds, FCN, N2O, and a polymer of composition (C3F5N)nwere detected as products in all three reactions; FCN and N2O are found only in very small amounts.Mechanisms for each of the reactions are discussed.

ISSN:0008-4042    

DOI:10.1139/v68-578

出版商:NRC Research Press    

年代:1968

数据来源: NRC