Give or Take: Effects of Electron-Accepting/-Withdrawing Groups in Red-Fluorescent BODIPY Molecular Rotors |
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| Authors: | Karolina Maleckait&#x; Domantas Narkevi
ius Rugil&#x;
il&#x;nait&#x; Jelena Dodonova-Vaitk nien&#x; Stepas Toliautas Sigitas Tumkevi
ius Aurimas Vy&#x;niauskas |
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| Institution: | 1.Center of Physical Sciences and Technology, Saulėtekio av. 3, LT-10257 Vilnius, Lithuania;2.Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko str. 24, LT-03225 Vilnius, Lithuania; (D.N.); (R.Ž.); (J.D.-V.); (S.T.);3.Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio av. 9-III, LT-10222 Vilnius, Lithuania; |
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| Abstract: | Mapping microviscosity, temperature, and polarity in biosystems is an important capability that can aid in disease detection. This can be achieved using fluorescent sensors based on a green-emitting BODIPY group. However, red fluorescent sensors are desired for convenient imaging of biological samples. It is known that phenyl substituents in the position of the BODIPY core can shift the fluorescence spectra to longer wavelengths. In this research, we report how electron-withdrawing (EWG) and -donating (EDG) groups can change the spectral and sensory properties of -phenyl-substituted BODIPYs. We present a trifluoromethyl-substituted (EWG) conjugate with moderate temperature sensing properties and a methoxy-substituted (EDG) molecule that could be used as a lifetime-based polarity probe. In this study, we utilise experimental results of steady-state and time-resolved fluorescence, as well as quantum chemical calculations using density functional theory (DFT). We also explain how the energy barrier height () for non-radiative relaxation affects the probe’s sensitivity to temperature and viscosity and provide appropriate ranges for the best possible sensitivity to viscosity and temperature. |
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| Keywords: | fluorescent probes photophysics molecular rotors microviscosity polarity sensing |
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