Donor functionalized BODIPYs

Abstract

In recent years research on BODIPY dyes has gained momentum. BODIPY dyes outdistance themselves from contemporary fluorophores due to their spectacular photonic properties and diverse applications. They exhibit strong absorption, high fluorescence quantum yield and excellent thermal and photochemical stability. Their diverse functionalization ability makes them one of the most explored fluorophore. The photonic properties of BODIPYs can be tuned by incorporating suitable functionality at the appropriate position. Their high electron affinity makes them strong acceptor. Incorporation of donor groups on the BODIPYs results in donoracceptor (D-A) systems. Donor-acceptor (D-A) molecules are highly polarized molecular systems, which exhibit intramolecular charge transfer and strong non-linear optical behaviour. The strength of the donor-acceptor interaction depends on the electron donating ability of the donor, electron affinity of the acceptor and nature of the spacer.The ferrocene is undoubtedly strong electron donor and exhibits high thermal and photochemical stability. The reversible oxidation of metal centre from Fe(II) to Fe(III) makes ferrocene a highly reversible redox centre and an ideal candidate for diverse electrochemical studies. Ferrocene is widely studied donor in D-A systems, and coupled with various acceptors like porphyrin, perylenediimide, benzothiazole, triazene and many more.The BODIPYs can be functionalized at α, β and meso positions. The functionalization at these positions perturbs the photonic properties of BODIPYs significantly. We have functionalized various positions of BODIPYs with ferrocenyl group through varying length of spacers and evaluated different positions of BODIPY for their superior electronic communication and further applications into efficient D-A systems.