Enhanced Fluorescence by Inter/Intramolecular Hydrogen Bonding in Si-Substituted Coumarins

Authors：Fan, Mengting; Tang, Yong; Li, Chen; Chen, Bo; Wang, Ting^*; Zhou, Panwang^*; Cui, Xiaoyan^*

Source：Journal of Physical Chemistry B, 2023, 127(14): 3187-3196.

DOI：10.1021/acs.jpcb.3c00609

• STATE DIPOLE-MOMENTS
• SOLVATION STATICS
• TRIPLET-STATE
• LASER-DYES
• BASIS-SETS
• SOLVENT
• ACRIDINE
• THERMOCHEMISTRY
• PHOTOPHYSICS
• DERIVATIVES

Introducing heteroatoms in organic fluorophores offers a unique strategy to tune their photophysical properties without dangling structural decorations. Silicon-substituted cou-marins (Si-coumarins) are the analogues of coumarin with the substitution of ester oxygen atoms by silicon atoms. In Si-coumarins, significant fluorescence enhancement in protic solvents through the formation of inter/intramolecular hydrogen bonds (H -bonds) offered great potential in various aspects with many unique photophysical properties. The energies of nx* and xx* states in Si-coumarins are elaborately tuned by inter/intramolecular H-bonds and solvents after incorporating silicon atoms. For example, the inter/intramolecular H-bonds elevate the energy of the nx* state in protic solvents, leading to an enlarged energy gap between the nx* and xx* states. Thus, fluorescence is enhanced by reducing the nonradiative transition through the nx* state in coumarins, resulting in many unique photophysical properties. The understanding of H-bonds in Si-coumarins offers more potential strategies for the design of novel fluorophores.

• Institution
  山东大学