Series of polymethine dyes derived from 2,2-difluoro-1,3,2-(2H)-dioxaborine of 3-acetyl-7-diethylamino-4-hydroxycoumarin

A series of symmetrical and unsymmetrical dyes with different polymethine chain lengths based on the 2,2-difluoro-1,3,2-(2H)-dioxaborine of 3-aceto-4-hydroxy-7-diethylaminocoumarin were obtained. It was shown that anionic symmetrical dyes are deeply coloured and highly intense dyes with good fluorescence properties and photostability.Spectral characteristics of the unsymmetrical dyes can be modified in a wide range by changing the electron-donating properties of the second terminal nucleus.