Styrene was copolymerized with methacrylic acid, itaconic acid, or malefic anhydride to obtain a copolymer containing about 50 mole per cent of styrene group. Each of the copolymers was nitrated and subsequently reduced to polyamino compound. It was shown by analysis that 1 to 1.5 amino groups had been intro-duced into each phenyl group along the molecular chain. The polyamino copolymers were diazotized and polymeric azo dyes were synthesized by coupling with other aromatic amines or naphthols. Cotton, acetate rayon, nylon and polyester fibers were dyed using naphthol as a grounder and the diazotized copolymer as a developer. The color was generally light brown or khaki, though it varied to some extent depending on the nature of fibers used. The dyeing properties and dyeing processes were discussed based on the polymeric properties.
The cumulative ortho effect observed in the ionization of substituted benzoic acids was discussed. It was pointed out that the nature of the cumulative ortho effects observed in 3, 4-, 2, 4-, 2, 5-, 2, 3-, and 2, 6-disubstituted benzoic acids varied and was distinguishable from each other. It has been demonstrated that the cumulative ortho effect involves various functions, such as the susceptibility for the substituent effects on the interaction between ortho substituents, the substituent effects itself on the interaction, the interaction itself, and in some cases, a combination of them. It was suggested that in the ionization of benzoic acids, the direct field effect between the point charge on the reacting group and the dipole of the ortho substituent was responsible for the ortho effect. Closer approach of the reacting group toward the 2-substituent which might be effected by introducing a second substituent into the 3- or 6-position of the 2-substituted benzoic acids would invert the direction of the dipole toward the point charge on the reacting group, and would therefore cause another ortho effect in a direction opposite to that of the usual acid strengthening ortho effect. Actually, this hypothesis has been supported by a number of examples.
In order to elucidate the nature of the ortho effect in the ionizations of substituted benzoic acids, microscopic dissociation constants of 2-substituted (OCH3, CH3, H, Cl, Br) 5-amino benzoic acids were determined in water at 25°C. Using those values, the substituent effects on the ortho effect in the ionization step were divided into those involved in the initial state and those in the final state of the equilibrium. Those substituent effects are very small compared with the ortho effect itself. Since the substituent effects on the steric inhibition of resonance are large (Part III), it is suggested that, in contrast with the views of the previous workers, the steric inhibition of resonance can not be the main cause for the ortho effect, and that the direct field effect would rather be the main factor responsible for this ortho effect.
In order to elucidate the nature of the ortho effect in the ionization of substituted anilinium ions, microscopic dissociation constants of 2-substituted (OCH3, CH3, H, Cl, Br) 5-carboxy anilines were determined in water at 25°C. As was mentioned in Part II, three substituent effects on the ortho effect were established ; those involved in the initial state, those in the ionization step, and those in the final state of the equilibrium. From those values, it was deduced that in the ionization of aniliniun ions, the direct field effect in the initial step would be the main cause for the ortho effect in this equilibrium, the steric inhibition of resonance in the final state also contributing as a minor factor.