Abstract
Abstract From the ESR spectroscopic point of view, there are two distinct species of ion pairs of the phthalonitrile anion with the lithium ion in ethereal solvents. One corresponds to the locating of the cation in close proximity to a cyano group. Its ESR spectrum exhibits the loss of twofold symmetry in the spin distribution on the anion (spectrum I) or an alternating line width (spectrum II), depending on the transfer rate of the cation between the two cyano groups. The other species refers to the locating of the cation probably in the spacing between the two cyano groups. The appearance of its spectrum (spectrum III) is similar to that of the free anion. The DME or THF solution gives spectrum II; the ethyl ether solution, spectrum III, and the THP or MeTHF solution, the superposition of spectrum I or II upon III. A similar two species are found in the sodium ion pair. The negative spin density at the meta-carbon atom to the cyano group where the cation is located has been found. The solvent and the temperature effects on the alkali metal splittings, a semi-quantitative treatment of the alternating line width, and the variations in the proton and nitrogen coupling constants are also described.
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