Fluorescence and solvent-dependent phosphorescence studies of o-nitrobenzaldehyde: a combined experimental and theoretical investigation.
The fluorescence and phosphorescence emission studies have been performed to understand the photochemistry of o-nitrobenzaldehyde in solution upon photoexcitation to the first excited singlet state (S(1)). The presence of an energy barrier in the S(1)-state hydrogen transfer potential energy surface is determined experimentally through the observed dual fluorescence emission, and the barrier height is estimated to be about 84-87 kcal mol(-1) by gradually decreasing the excitation energy. The phosphorescence spectra of o-NBA in five different solvents are observed for the first time, providing direct experimental evidence on the existence of triplet manifold in the photoexcitation of o-NBA. Furthermore, the relative phosphorescence quantum yield is found to be solvent dependent. To get further insights into the dynamic process involved in the photochemistry of o-NBA, excited state calculations at the TD-B3LYP/6-311+G(d,p) level of theory with the PCM model are accomplished, which strongly support our experimental findings.
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Shibo
S
Cheng
Peng
P
Song
Songqiu
S
Yang
Hongming
H
Yin
Keli
K
Han
D001547:Benzaldehydes / Q000737:chemistry*; D008962:Models, Theoretical; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D001547:Benzaldehydes; D012997:Solvents; C043850:2-nitrobenzaldehyde