Boradipyrromethenecyanines of different electronic symmetry: A demonstration of the potential of BODIPY nucleus as end group in polymethine chromophoric system

Abstract Symmetrical anionic polymethine dye and series of unsymmetrical ones – merocyanines and anionic – were obtained from the BODIPY with enhanced reactivity of meso -methyl group. This allows observing in detail the transformation of borondipyrromethene chromophoric system through intermediate polyene state into the polymethine one. Symmetrical dye has absorption maximum at 828 nm, i.e. BODIPY as end nucleus in polymethine dyes has one of the highest values of “effective length” among known long-wavelength prototypes. Spectral properties of unsymmetrical dyes may be changed in a wide range by combining the second end core.