Researchers from Krestov Institute of Solution Chemistry (Ivanovo) and Catholic University of Leuven (Belgium) have synthesized a new BODIPY and a hydrophilic BODIPY-Sn(IV)porphyrin-BODIPY triad on its basis.
Difluoroboryldipyrromethene dyes (BODIPY) are of great interest as fluorophores, which are gaining more and more popularity among fluorescent organic dyes. To provide a boron-pyrin dye with desired functional properties, it can be easily modified in the α-, β- and meso-positions, as well as by replacing fluorine atoms with functional fragments of different nature. The emmisivity of BODIPY fluorophores is largely affected by steric and electronic effects of substituents that change the delocalization degree of their π-electron system.
Of special interest is modification of BODIPY molecules via their conjugation with fluorophores of different nature. Such conjugates often serve as model systems for studying the targeted photo-induced electron and/or energy transfer, in which boron-pyrins can act as a donor or an acceptor. There are a number of works, which describe BODIPY conjugates with a variety of organic compounds, including porphyrin ligands or their metal complexes. Porphyrinates with BODIPY ligands in axial positions were studied as models of targeted photo-induced electron and/or energy transfer. The energy transfer under excitation and establishing its direction in molecular fragments of a hybrid dye depend on a number of factors: nature of the medium, porphyrinate macrocycle and fluorophore ligand, including the nature of the spacer binding the functional fragments with each other.
Researchers from ISC RAS and Catholic University of Leuven (Belgium) have synthesized a new BODIPY and a hydrophilic BODIPY-Sn(IV)porphyrin-BODIPY triad on its basis. The conformationally-flexible methylphenol group in the obtained triad plays the role of a spacer binding the porphyrin and boron-pyrin fragments. The researchers have also established a dependence of their spectro-luminescent and sensor properties on the acidity and local viscosity of the medium. They showed that the fluorescent sensitivity of the triad porphyrin fragment to the local viscosity of the medium is the result of a photo-induced energy transfer from the BODIPY axial fragments to the porphyrin macrocycle. Of special interest is that the developed hybrid fluorophore is sensitive to the slightest changes in the medium viscosity within the range of values comparable to that of a healthy human's blood. This discovery opens up prospects for developing molecular devices on its basis for monitoring physiological and pathological processes in blood and evaluating disease treatment efficiency as a whole. To learn more about the study results see: https://www.sciencedirect.com/science/article/pii/S0167732223019797.
