Synthesis, photophysical properties and theoretical studies of new bis-quinolin curcuminoid BF₂-complexes and their...

This paper presents the synthesis and characterization of two series of new bis-quinolin curcuminoid BF₂-complexes 11 and their respective decomplexed bis-quinolin curcuminoid derivatives 12, in an attempt to understand their optical properties. The synthesized compounds showed interesting fluorescent characteristics in both solution and in solid-state. The characteristic of the electronic transitions involved in these systems were measured via Uv-vis spectroscopy and fluorescence spectroscopy. Results revealed that the absorption and emission bands are dependent of the structure of compounds 11 and 12 but also of the type of substituent, even showing a push-pull behavior in those derivatives substituted with methyl group. These findings were also confirmed through computational calculations at DFT level via simulations of the Uv-vis spectra and determining the topology of the border orbitals responsible for light absorption.