Theoretical investigation on the geometry and vibrational spectra of N-acetyl-5-methoxytryptamine: Theoretical and computational chemistry

The geometry and vibrational spectra of biological antioxidant N-acetyl-5-methoxytryptamine have been studied by using the B3LYP and B3PW91 methods combined with the SQM theory. These results show that the two methods give a similar geometry. The potential energy distributions (PEDs) show that the highest frequency of vibrational spectra is 3621 cm, which is produced by the stretching vibration mode of N-H bond with the absorption strength of 80.69 KM/mol. And the strongest absorption peak is contributed by the stretching vibration mode of the carbonyl group with frequency of 1740 cm and absorption strength of 291.55 KM/mol in the infrared spectra. But for the Raman spectra, the strongest absorption peak is contributed by the stretching vibration mode of the three carbon hydrogen bond in methoxy group with frequency of 2947 cm^-1 and absorption strength of 192.20 KM/mol.