The search for fluorophores with intense absorption and emission in the red region of the spectrum is an important task, as such compounds can be used in fluorescence imaging, providing high image resolution due to the deep penetration of low energy photons into tissues. In this paper, we present the results of the synthesis and photophysical characterization of a novel ms-benzimidazole-4,4′,5,5′-tetramethyldipyrromethene bis(difluoroborate) (BOIMPY) compound, which exhibits intensive absorption and emission in the long-wavelength region while maintaining high fluorescence quantum yields (up to 60%). Using DFT analysis, we investigated the geometry of BOIMPY in both ground and excited states and described the influence of the molecular structure on its practically relevant photophysical properties.
