Ion multiplet

When the ion is embedded in a matrix, the crystal field splits the ground multiplet and the crystal field levels give rise to the same problem as the free ion multiplets, to be solved in the same way. If several crystal field levels are involved, a complete treatment using Eq. (13) is needed. 

Tetrakis(acetato)ditungsten(II) is a very air-sensitive, bright yellow, diamagnetic solid. It is moderately soluble in THF and acetonitrile but solutions in the latter solvent decompose after several hours. The 360 MHz XH NMR spectrum (in THF-d8) consists of a single methyl resonance at S 2.91. The mass spectrum (solid probe, electron impact, 40-70-eV ionizing voltage) shows the parent ion multiplet at m/e 604. Other spectroscopic data and physicochemical properties are described in the literature.8... 

Figure 3. Calculated and average observed peaks in the parent ion multiplets ...

The splitting of free-ion levels by the action of a crystal field depends on the symmetry of the crystal field which in turn reflects the symmetry of the arrangement of the neighboring ions. This property can thus be used to get evidence about the point group symmetry of a site in a given solid once the splitting of the free-ion multiplets have been determined (see, for example, sect. 5.8 of Gorller-Walrand and Binnemans (1996)). This can be a very useful... 

The first term on the right hand side is simply the relative intensity of the state l a. S L y without spin-orbit coupling. The formula then gives the intensity of the ion multiplet component J starting from a component J of the ground state, and involves a 9—/ coefficient, which may be evaluated from standard formulae (17). The summation is over the two values of / = l — and l... 

Examples of transition curves (ac susceptibility) which undergo a return to the normal state at a lower critical temperature and the corresponding re-entrant reduced transition temperature vs Ce concentration curve for the (LaCelAU system are shown in figs. 11.9(a) and (b) (Maple et al., 1972). The data are also compared with the predictions of the Abrikosov-Gor kov (AG) theory (Abrikosov and Gor kov, 1961) (dashed line) which hold for superconducting matrix-impurity systems for which there is no Kondo effect > 0) and for which the degeneracy of the Hund s rule impurity ion multiplet is not lifted by a crystalline electric field. 

This reversal is apparently caused by ion multiplets which diffuse more slowly through ammonia than the simple ions. 

Total splittings of the R ion multiplets in crystals are of the order of 100-1000 K, and for treatment of magnetic properties of the lanthanide compounds at all temperatures of interest, analysis of the Stark stmcture of a ground multiplet without its admixture... 

Telechelic ionomers are a special class of ionic polymers in which the charged groups are situated exclusively at the chain ends (see Telechelic Polymers (85,86)) Accordingly, their solid-state structure is characterized by self-assembly of the chain ends into ion multiplets or ionic clusters. Because of this defined... 

The kinetics of electron-exchange and electron-transfer reactions involving the optically active [Co(phen)3] + +, [Co(4,7-Me2phen)3] +, and [Co(5,5-Me2phen)3] couples have been studied. The self-exchange rate constants were observed to be dependent on the nature of the counterion, with an acceleration effect in the order CIO >N07 >Br >C1 , and the formation of ion multiplets is proposed. Flash photolysis kinetic measurements on the oxidation of several cobalt(II) polyaza macrocycles by [Ru(bpy)3] + and [Cr(bpy)3] + have been reported. ... 

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