SPECTROCHEMICAL STUDIES OF HYDROXYAZO-COMPOUNDS. PART III
作者:Taku Uemura、Naomichi Yokojima、Tamimatsu Endo
DOI:10.1246/bcsj.2.48
日期:1927.2
1. Tautomeric transpositions may take place in these hydroxyazo-compounds by the addition of a potassium hydroxide solution, with an accompanying change in colour.2. We can respectively assign A(azo)-, R(red)-, and B(blue)-forms to these tautomers. (Sometimes we recognise more readily the mixture of these forms.)3. Tautoinerism is due to the labile hydrogen atoms in hydroxyl-groups which take the ortho- or para-position with respect to the azo-group.4. The hydrogen atom which is in the meta hydroxyl-group with regard to the azo-group does not only move by itself, but moreover hinders the transposition of the other hydrogen atoms.5. When there are many labile hydrogen atoms, mutual hindrance may occur.6. B-form is sometimes produced only when there is a para nitroradical with regard to the azo-group.7. Nitro-groups which take the ortho- or meta-position with respect to the azo-group do not change into the isonitro-structure.8. The nitro-group has considerable bathochromic influence upon these hydroxyazo-compounds.9. Generally only one absorption band exists in the solutions, of these substances, but there are two bands when methyl-group is included.