• Spectroscopy and Spectral Analysis
  • Vol. 41, Issue 9, 2859 (2021)
The molecular structure of ABA
Fig. 1. The molecular structure of ABA
Molecular orbital energy level diagram of ABA
Fig. 2. Molecular orbital energy level diagram of ABA
Distribution of molecular orbital electron clouds of ABA
Fig. 3. Distribution of molecular orbital electron clouds of ABA
The comparison of DFT calculation, Raman and SERS experiment of ABA
Fig. 4. The comparison of DFT calculation, Raman and SERS experiment of ABA
Infrared absorption spectra of ABA(IR)(a): Experiment-IR spectrum; (b): DFT-IR spectrum
Fig. 5. Infrared absorption spectra of ABA(IR)
(a): Experiment-IR spectrum; (b): DFT-IR spectrum
1H-NMR of the ABA
Fig. 6. 1H-NMR of the ABA
13C-NMR of the ABA
Fig. 7. 13C-NMR of the ABA
NumberDFT
/cm-1
Raman
/cm-1
SERS
/cm-1
Assignments
1392401398τ(O7-H33), ω(C9-H26); ω(C19-H37-H381-H39)
2552558ρ(C24-H25), τ(C2-C4)
3616612598ω(C3-H23); ρ(C5-H24-H25)
4865846τ(C9-C10)
5928ω(C12-H28), ω(C3-H23)
61 0561 0481 032ω(C16-H30-H31-H32), ω(C1-H20-H21-H22), ω(C19-H37-H381-H39),
ω(C18-H35-H36-H34), ω(C10-H27)
71 1841 1881 174νs(C12-C13), νas(C13-O15), ρ(O15-H29), ρ(O17-H33)
81 2721 2711 268νs(C3-C4), νas(C7-C8), τ(C6-H24-H25)
91 3041 3211 310νas(C3-C4), τ(C6-H24-H25), ρ(C10-H27), ρ(C9-H26), ρ(O17-H33), ρ(C3-H23)
101 3521 3751 372νas(C8-C2), ρ(C3-H23), ρ(C9-H26), ρ(C10-H27)
111 408νas(C16-C11), ρ(C10-H27), ρ(C12-H28), ω(C16-H30-H31-H32)
121 4431 437νas(C16-C11), ρ(C10-H27), ρ(C12-H28), ω(C16-H30-H31-H32)
131 544τ(C18-H34-H35-H36), τ(C19-H37-H38-H39), ω(C6-24H), ω(C6-25H)
141 656νs(C11-C12), νas(C12-C13), νas(C9-C10)
151 6881 6351 625νs(C9-C10), νas(C11-C12)
161 6541 639νs(C11-C12), νas(C12-C13), νas(C9-C10)
171 744νs(C4-O5)
181 768νs(C13-O14), νas(C12-C13), νs(C9-C10)
192 9052 898νas(C18-H34-H35-H36)
202 9352 921νas(C5-H25), νas(C5-H24)
213 0483 039νas(C1-H20-H21-H22)
223 088νas(C16-H30-H31-H32)
233 184νas(C3-H23)
243 200τ(C9-H26), τ(C10-H27), τ(C12-H28)
253 688νas(O15-H29)
263 760νas(O17-H33)
Table 1. DFT, Raman and SERS characteristic peaks of ABA and their attribution
1H1345678910
Experiment/ppm2.5130.9220.9582.4992.5042.5086.2125.1995.672
DFT/ppm2.4671.0111.0232.4783.5562.5626.0235.0435.564
Δλ0.046-0.089-0.0650.022-1.052-0.0540.1890.1560.108
1H111314151617181920
Experiment/ppm5.8111.8241.9756.25312.0601.9782.0872.1307.747
DFT/ppm5.8891.7681.7896.45311.9761.6762.0422.0477.987
Δλ-0.0780.0560.186-0.20.0840.3020.0450.083-0.24
Table 2. 1H-NMR relative displacement of ABA
13Cabcdefgh
Experiment/ppm197.19939.705127.22578.350137.402125.897149.242163.138
DFT/ppm194.99241.107126.32284.836131.231132.605155.148176.923
Δλ2.207-1.4020.903-6.4866.171-6.708-5.906-13.785
13Cijklmno
Experiment/ppm40.122137.402166.86418.81120.83823.18324.154
DFT/ppm34.013134.423177.58917.56421.00122.38623.436
Δλ6.1092.979-10.7251.247-0.1630.7970.718
Table 3. 13C-NMR relative displacement of ABA