Communication
ChemComm
In conclusion, a visible-light photooxidative coupling reac-
tion for the formation of disulfides was achieved using p-ATP as
a model reactant in the absence of photo catalyst or plasmonic
nanoparticles. Very similar to the conversion of p-ATP to DMAB
with plasmon-assisted photocatalysis, high light power density,
neutral to alkaline conditions, dissolved oxygen and water are
more favorable for the formation of photo-induced disulfide
through the p-aminophenylthiyl radical reaction pathway, pro-
viding a green and important route for disulfide synthesis. In
addition, DFM was successfully exploited to monitor the
visible-light photo-induced organic transformation in real time
and in situ at the single organic nanoparticle level, providing a
supplementary visualization approach to monitor some reac-
tions easily ignored in SERS research because the normal
2
0
Raman signal of the p-ATP solution is weak. The photo-
induced disulfide formation mechanism at the precise
Fig. 3 Characterization of p-aminophenylthiyl radicals. Evolution of the
transient absorption spectra of 1 mM p-ATP aqueous solution acquired at
different delay times following 350 nm excitation during the rising (A) and atomic/molecular level should be further explored and under-
2
1
decaying (B) of the radical absorption. (C) Time-dependency of the radical stood by more spectral analysis and theoretical calculations.
absorption intensities obtained at 572 nm; the insert shows an expanded
This work was financially supported by the National Natural
Science Foundation of China (NSFC, No. 21874109).
view for the first 1.0 ps. (D) EPR spectra of the DMPO/p-aminophenylthiyl
radical adduct. Spectrum obtained before (a, red line) and after (b, green
line) irradiation of 100 mM DMPO with 50 mM p-ATP water-DMF mixture
solution by a xenon lamp (300 W, with a 400 nm cut-off filter) for 10 min.
Computer simulation of the spectrum observed in spectrum b with Conflicts of interest
N H
hyperfine splitting constants a = 14.23 G and a = 16.17 G (c, blue line).
EPR spectrometer settings: modulation amplitude, 1.0 G; microwave There are no conflicts to declare.
frequency, 10 GHz; microwave power, 19 mW; time constant, 10 ms.
Notes and references
magnitudes obtained at the probe wavelength of 572 nm (Fig. 3C)
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0
17
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Chem. Commun., 2021, 57, 4190–4193 | 4193