Acenaphthylene, proton sponges

When l,8-bis(dimethylamino)-4-vinylnaphthalene (121) is heated with 3,6-diphenyl-s-tetrazine (DFT), a [4 + 2]-cycloaddition reaction with reverse electron demands takes place to give the 1,4-dihydropyridazine derivative 208 (Scheme 37). The latter could be oxidized with chloranil or with excess of DFT to pyridazine 209118. A similar reaction with acenaphthylene proton sponge 107 gives directly the annelated pyridazine 139, since the intermediate dihydropyridazine is readily oxidized in air. It was established that the reactivity ratio of compounds 107, 121, 5-dimethylaminoacenaphthylene and acenaphthylene in the reaction with DFT is equal to 32 17 14 1, respectively. These data are in... 

It was recognized that acenaphthene 40 and acenaphthylene 107 proton sponges, unlike the pair of compounds 11 and 124, easily interconvert by oxidation and reduction, respectively38. Since in the course of this transformation, the basicity change amounts to over four plsfa units (equation 11), these compounds form a redox system with easily modified basicity. It is believed that such properties may be of use in creating molecular devices38. 

Pozharskii, A.F., Ozeryanskii, V.A. and Starykova, Z.A. (2002) Molecular structure of 5,6-bis (dimethylamino)acenaphthene, 5,6-bis(dimethylamino)acenaphthylene, and their monohydrobromides a comparison with some naphthalene proton sponges. Journal of the Chemical Society - Perkin Transactions 2, 318-322. 

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