Spectral-luminescence properties and acid-base properties of luminophores obtained from 3-iodo-7-dialkylaminocoumarins

The absorption and fluorescence spectra of the conjugate acids of 7-dialkylaminocoumarins were studied, and their pK_a ^I, pK_a ^II, and pK_a ^* values were determined. It was established with the aid of PMR data that the primary protonation generally involves the nitrogen-containing substituent in the 3 or 4 position, while the secondary protonation involves the nitrogen atom in the 7 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1170–1175, September, 1991.