Anthracene dianion

We can find only one sample of a rate constant for a similar reaction. Anthracene dianion (A2-) reacts with 1,1-diphenylethylene (D) as... 

The dependence of NMR patterns upon states of solvation should not be overlooked. This aspect of polyanion chemistry has been discussed (Sect. 4). The influence of the counter cation upon the dianion though unaccounted for by simple calculations is supposed to vary from system to system. The different topologies of the anions and different modes of delocalization may be responsible for the deviations from a linear dependence of the correlation. From Table 9 one can arrive at conclusions on the relative antiaromaticity of the various anions. For example, benzanthracene dianion 49 ) is less antiaromatic than chrysene dianion (542 ), and dibenzo-anthracene dianion (J/2-) is more antiaromatic than the pentacene dianion (472 ). It is also proposed that H NMR paratropic shifts may be used to calibrate the LUMO-HOMO energy gap. 

Like the naphthalene dianion, the anthracene dianion is distinctly nonplanar (Figure 6). However, there is some indication from the results obtained for this complex that the angular distortions observed in both the naphthalene and anthracene dianions may be caused by interactions of the unsaturated carbanion with the LiTMED group. There are three preferred sites in anthracene to which the lithium atom is most likely to... 

Figure 37. Molecular orbitals for the anthracene dianion. The orbitals have the appropriate symmetry to overlap with the lithium p orbitals that are parallel to the mean plane of the dianion (100) (see Figure 34).

Figure 3. The effect of temperature on the line shape of the lH NMR spectrum (300 MHz) of the anthracene dianion (3) as a disodium salt in THF-d8. A 293 K, B 263 K, and C 223 K. S indicates a solvent signal. (Reproduced from reference 20. Copyright 1983 American Chemical Society.)...

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