Synthesis and photophysical properties of 2-aryl-5-carbonyl indolizines

• Published in: Dyes and pigments 2022-02, Vol.198, p.109996, Article 109996
• Main Authors: Bertallo, Camila R.S., Berlim, Leonardo S., Olivier, Danilo S., Arroio, Thais R., Ito, Amando S., Clososki, Giuliano C.
• Format: Article
• Language: English
• Subjects: DFT calculations; Fluorescent heterocycles; Indolizines; Metalation
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2021.109996

Herein we reported the synthesis of 20 novel fluorescent 5-carbonylated 2-arylindolizines derivatives through the reaction between organolithium intermediates with different electrophiles. To investigate the effects of the substituents on the wavelengths of electronic absorption spectra, fluorescence emission, quantum yield and Stokes shift, the photophysical properties of these molecules were evaluated. Maximum absorbance peaks were observed around 256–460 nm and maximum fluorescence emission around 485–548 nm. The fluorescence decay curves showed one or two decay times depending on the substituents with emission lifetime around 4–11 ns in methanol and 5–12 ns in DMSO. Quantum yield values ranged from 0.04 to 0.39 and Stokes shifts varied among 3.6–25 × 103cm−1. DFT calculations were also performed. •20 new fluorescent 5-carbonylated 2-arylindolizines derivatives synthesized.•Novel indolizines have suitable photophysical properties for use as bioprobes.•DFT calculations showed predominant transitions from the HOMO to LUMO orbitals.•Reactive sites capable of making covalent linkage with several biomolecules.