Table 5 Comparison between grinding method and organic solvent method
Entry
Synthetic method
Time/min
Temperature/°C
Yield of NNS/%
1
Grinding method
20
r.t.
55.0
2
Organic solvent method in DCM
60
40
49.6
3
Organic solvent method in DMF
60
40
48.2
Fig.4 Normalized UV absorption (A) and fluorescence spectra (D) of NNS in different solvents (dichloromethane,tetrahydrofuran,n-hexane, toluene, acetone, acetonitrile); Normalized UV absorption (B) and fluorescence spectra (E) of MOS in different solvents; Normalized UV absorption (C) and fluorescence spectra (F) of MES in different solvents
Fig.4 Normalized UV absorption (A) and fluorescence spectra (D) of NNS in different solvents (dichloromethane,tetrahydrofuran,n-hexane, toluene, acetone, acetonitrile); Normalized UV absorption (B) and fluorescence spectra (E) of MOS in different solvents; Normalized UV absorption (C) and fluorescence spectra (F) of MES in different solvents
Fig.5 (A) Normalized UV absorption spectra of NNS, MOS and MES in THF; (B) Normalized fluorescence spectra of NNS, MOS and MES in THF, the excitation wavelengths of NNS, MOS and MES were 425 nm, 360 nm and 350 nm, respectively.Illustration: Luminescence images of THF solutions of NNS, MOS and MES under a 365 nm fluorescent lamp
Fig.5 (A) Normalized UV absorption spectra of NNS, MOS and MES in THF; (B) Normalized fluorescence spectra of NNS, MOS and MES in THF, the excitation wavelengths of NNS, MOS and MES were 425 nm, 360 nm and 350 nm, respectively.Illustration: Luminescence images of THF solutions of NNS, MOS and MES under a 365 nm fluorescent lamp
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