1956 年 76 巻 6 号 p. 733-736
Color change of 4, 5-dinitrofluorescein, i.e. the change of its configuration, is assumed to take the forms indicated by (A), (B), (C), and (D). Mercuration of this compound with mercury acetate, at various pHs between 3.6 and 7.2 with heating, invariably affords a mixture of 2, 7-dimercuri (I) and 2-mercuri (II) compounds, with a residue of unreacted material. The yield of the mercury compounds decreases with the increasing pH value and the mercuration is not effected at pH 7.6 with the appearance of a reduction reaction.
Mercuration of 3′, 3″-dinitrophenolphthalein (range of color change, pH 5.9-7.4) at pH 4-8.5 was not accompanied with any reduction reaction but afforded 5′-mercuri and 5′, 5″-dimercuri compounds and recovery of a small amount of the unreacted material.
The appearance of a reductive action in dinitrofluorescein, in contrast to its absence in dinitrophenolphthalein, is assumed to be due to the fact that the fluorescein derivative forms the so-called hydrate in an alkaline range by the effect of the nitro groups in the 4 and 5 positions, thereby constituting a resorcinol ring.