Weitz, Ernst published the artcileFree ammonium radicals. VI. Radicals and meriquinonoid compounds. I. The dipyridinium subhalides, Application In Synthesis of 47369-00-6, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1926), 432-45, database is CAplus.
cf. C. A. 18, 2168. It was suggested in the earlier paper that the deeply colored compounds assumed by other investigators to be dimeric quinhydrones (I) consisting of 1 mol. dipyridinium dihalide + 1 mol. dihydrodipyridyl (II) are in reality monomol. mono- or subhalides (III) of the dipyridinium radical (IV), a valence-tautomeric form of II. Mol. weight determinations of dibenzylpyridinium subchloride (V) in boiling MeOH gave mean values corresponding to 0.5 that calculated for III, indicating that the V in solution is almost completely ionized into IV and Cl–; these determinations have been repeated in a perfected apparatus, in which the mol. weight of N,N’-diphenyldipyridinium subchloride (VI) has also been determined; the new determinations fully confirm the older observations. The higher result for V obtained by Emmert, Jungek and Häffner (C. A. 19, 518), from which they conclude that it is a I and ionizes into 3 parts (complex cation and 2 Cl ions) are explained by the fact that they used more concentrated solutions To establish that in their own solutions there is only electrolytic dissociation and not “quinhydrone decomposition,” W. and F. determined whether Beer’s law held for their solutions of V, using a specially constructed apparatus which made it possible to exclude every trace of atm. O; no lightening in the color could be detected either on dilution or heating. The IV are assumed to be univalent radicals in which the “odd” electron oscillates about the 2 central γ-C atoms. The anion in “bridged” union with the 2 halves of the IV need not be taken into account in these considerations; (see structure) it may be fixed at any point of the mol. or crystal lattice, the necessary oscillation in the affinity distribution being taken care of by the “odd” electron. This conception of a vibrating electron, which differs from older oscillation theories, especially that of Baeyer, in that it is only electrons and not atoms which are assumed to vibrate, can be applied to many other so-called intramol. quinhydrones, i. e. to large classes of dyes like those of the Ph3CH series. A N,N’-dibenzyl-γ,γ’-dipyridinium “two-thirds”-iodide, C24H22N2I2.2C24H22N2 (VII), was occasionally obtained instead of the normal III on treating the radical with the diiodide, but the formation of this and similar polymol. compounds is not at all contrary to the monomol. formulation of the III, for both the dipyridinium salts (with their coordinately unsaturated N atoms) and the radicals have enough unsaturated positions at which addition of other mols. can take place. The b. p. apparatus was so constructed that the determinations could be made in an atm. (not in a current) of CO2 exactly under atm. pressure. Using 0.93 as the b. p. constant of the MeOH, the mol. weight of Bz2 was found in this apparatus to be 192-226 (mean of 11 determinations, 210; calculated, 210); of PhNHAc, 139-44 (mean of 6 determinations, 142; calculated 135); of V in N/17.1-N/47.0 solution, 172-220 (mean of 18 determinations, 197); in N/11.5-N/15.3 solution, 203-229 (mean of 4 determinations, 215; calculated for III/2, 187); of VI in N/21.3-N/22.9 solution, 172-6 (mean of 3 determinations, 174; calculated for III/2, 173). On the other hand, dibenzyldipyridinium dichloride gave mol. weights of 253, 243 and 238 for V 31.3, 15.6 and 41.7, resp. (calculated for C24H22N2Cl2/2, 204). That the III represent an entirely independent stage of oxidation is further confirmed by the fact that they dissolve without decomposition in AcOH (at room temperature) while the corresponding free radicals dissolve only with decomposition VI, prepared like the subiodide, forms steel-blue crystals with violet tinge and metallic luster. VII forms a dark violet, indistinctly crystalline mass.
Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C6H8N2, Application In Synthesis of 47369-00-6.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem