A General Strategy to Enhance Donor‐Acceptor Molecules Using Solvent‐Excluding Substituents

Abstract

While organic donor‐acceptor (D‐A) molecules are widely employed in multiple areas, the application of more D‐A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent‐dependent mechanisms of excited‐state quenching through addition of a β‐carbonyl‐based polar substituent. The results reveal a mechanism wherein the β‐carbonyl substituent creates a structural buffer between the donor and the surrounding solvent. Through computational and experimental analyses, it is demonstrated that the β‐carbonyl simultaneously attenuates two distinct solvent‐dependent quenching mechanisms. Using the β‐carbonyl substituent, improvements in the photophysical properties of commonly used D‐A fluorophores and their enhanced performance in biological imaging are shown.

Inactivation of Competitive Decay Channels Leads to Enhanced Coumarin Photochemistry

“…In the fast range, there are rotations, vibrations, and isomerization around single atoms or bonds. Also, internal conversion (heat loss to the solvent) [20] or hydrogen‐bonding [21] can lead to relaxation to the ground state [22] . If the excited state lives long enough (e. g. nanoseconds) and does not decay in any of the faster channels, the molecule can also release the energy via luminescence, [23] or a directed bond cleavage.…”

ACQ to AIE transformation of quinoline derivatives: modulating substituent electronic effects to alter excited-state reorganization energy distribution

“…When highly polar water was added to their DMA solutions, the presence of charge-transfer excitations caused a red shift in the emission wavelength. 28…”

“…When highly polar water was added to their DMA solutions, the presence of charge-transfer excitations caused a red shift in the emission wavelength. 28 The root-mean-square deviation (RMSD) is a quantitative metric frequently employed to measure geometric differences between ground-state and excited-state structures. 23 To evaluate the variability in RMSD values among these quinoline derivatives, the VMD program was utilized to calculate the RMSD.…”