The two-electron transition,4 T 1g (F) →4A2g(F), in the spectra of octahedral oxygen-coordinated cobalt(II) species

Summary The spectra of octahedral cobalt(II) species in sodium ultraphosphate glasses show the two-electron transition,⁴ T _1g (F) ⁴ A _2g (F), as a resolved band, separate from the intense one-electron transition⁴ T _1g (F) ⁴ T _1g (P), which normally masks it in the visible spectra of cobalt(II) hydrates.     

The3 A 2g →3 T 1g(F) transition in the spectrum of some oxygen-ligated octahedral nickel(II) species

Summary In sodium phosphate glasses, nickel(II) is octahedrally coordinated by the oxygens of the phosphates with ₀ = 7600 cm^–1 and B = 920 cm^–1. Contrary to the case of many other oxygen-coordinated systems including [Ni(H₂O)₆]²⁺ and low alkali borate glasses, the second spin-allowed transition to³ T _1g(F) appears as a single-peaked band well-separated from the spinforbidden transition to¹ E _g(D). Variation of the glass composition does not change the main features of the spectrum. Dissolving the glasses in water results in a shift of all the bands to higher energies with the second spin-allowed band becoming triple-peaked. This supports Liehr and Ballhausen's explanation of the structure of this band.Part of a thesis submitted by T. Genena in partial fulfillment of the M.Sc. degree in Solid State Science, 1985.     

Kinetics of reactions of the tris-(4-methyl-1,10-phenanthroline)iron(II) cation

Summary Kinetic parameters are reported for aquation of the tris-(4-methyl-1,10-phenanthroline) iron(II) [Fe(4-Mephen)₃]²⁺, cation and for its reactions with hydroxide, cyanide, and peroxodisulphate. Activation volumes have been determined for the two last-named reactions; they reflect the importance of solvation changes in transition state formation.     

Thorium(IV) and uranium(VI) complexes with some heterocyclic azo dyes in absolute ethanol

Thorium(IV) and uranium(VI) chelate complexes with PAN, PAR, TAN and TAR have been studied in absolute ethanol. The uranyl ion forms complexes with PAN, PAR, TAN and TAR in the metal to ligand molar ratio of 1:1. Thorium(IV) forms complexes with PAR, TAR and TAN in the molar ratio of 1:2. In case of Th(IV)-PAN complexes the molar ratio is 1:2.4. The stability constants for all the above complexes have been worked out using the mole ratio method. The kinetics of aquation of Th(IV)-PAN complexes indicate that PAN acts as a tridentate ligand.