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Driving the Emission Towards Blue by Controlling the HOMO-LUMO Energy Gap in BF₂ -Functionalized 2-(Imidazo[1,5-a]pyridin-3-yl)phenols.

ABSTRACT: Several boron compounds with 2-(imidazo[1,5-a]pyridin-3-yl)phenols, differentiated by the nature of the substituent (R) in the para position of the hydroxy group, have been synthesized and thoroughly characterized both in solution (¹ H, ¹³ C, ¹¹ B, ¹⁹ F NMR) and in the solid state (X-ray). All derivatives displayed attractive photophysical properties like very high Stokes shift, high fluorescence quantum yields and a good photostability in solution. Time-Dependent Density Functional Theory (TD-DFT) calculations allowed to define the main electronic transitions as intra ligand transitions (¹ ILT), which was corroborated by the Natural Transition Orbitals (NTOs) shapes. The HOMO-LUMO energy gap was correlated to the electronic properties of the substituent R on the phenolic ring, as quantified by its σ_p Hammett constant.

SUBMITTER: Colombo G

PROVIDER: S-EPMC8456857 | biostudies-literature |

REPOSITORIES: biostudies-literature

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