Studies on the Determination Methods with Polyaldehydes. X. : Phosphorimetric Determination of m-Iodoaniline with Phthalaldehyde

Abstract

Phosphorescence and fluorescence at 77°k were compared in 2-phenylphthalimidines having a substituent (OH, OCH₃, CH₃, H, Cl, Br, I, COOH, SO₂NH₂, NO₃, 2', 3'-benz., 3', 4'-benz.) in the phenyl group at 2-position. Mean life time of the phosphorescence of 2-(m- or p-halogenophenyl) phthalimidines showed the internal heavy atom effect of the substituted atoms and the mean life time decreased in the order of chlorine, bromine, and iodine. The life time of p-halogen substituted compounds was smaller than that of m-halogen compounds. Based on these facts phosphorimetric determination of m-iodoaniline was devised which relied on the phosphorescence reaction by the formation of 2-phenylphthalimidines from phthaladehyde and aromatic primary amines in sulfuric acid-ethanol solution. This phosphorescence method was not interfered by ο-iodoaniline, p-iodoaniline, N-methylaniline, N, N-dimethylaniline, benzylamine, or urea, and its selectivity was better than that of fluorescence method.