Open AccessExcited-State Dynamics of a Substituted Fluorene Derivative. The Central Role of Hydrogen Bonding Interactions with the Solvent
Author(s) -
Briana A. Capistran,
Stephen H. Yuwono,
Mehdi Moemeni,
Soham Maity,
Aria Vahdani,
Babak Borhan,
James E. Jackson,
Piotr Piecuch,
Marcos Dantus,
G. J. Blanchard
Publication year - 2021
Publication title -
the journal of physical chemistry. b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 392
eISSN - 1520-6106
pISSN - 1520-5207
DOI - 10.1021/acs.jpcb.1c06474
Subject(s) - photoexcitation , photochemistry , fluorene , solvent , chemistry , relaxation (psychology) , hydrogen bond , excited state , aldehyde , singlet state , molecule , computational chemistry , solvent effects , delocalized electron , chemical physics , organic chemistry , catalysis , atomic physics , psychology , social psychology , physics , polymer
Substituted fluorene structures have demonstrated unusual photochemical properties. Previous reports on the substituted fluorene Schiff base FR0 -SB demonstrated super photobase behavior with a Δp K b of ∼14 upon photoexcitation. In an effort to understand the basis for this unusual behavior, we have examined the electronic structure and relaxation dynamics of the structural precursor of FR0 -SB, the aldehyde FR0 , in protic and aprotic solvents using time-resolved fluorescence spectroscopy and quantum chemical calculations. The calculations show three excited singlet states in relatively close energetic proximity. The spectroscopic data are consistent with relaxation dynamics from these electronic states that depend on the presence and concentration of solvent hydroxyl functionality. These results underscore the central role of solvent hydrogen bonding to the FR0 aldehyde oxygen in mediating the relaxation dynamics within this molecule.