Application of Quantum–Chemical Methods in the Forensic Prediction of Psychedelic Drugs’ Spectra (IR, NMR, UV–VIS, and MS): A Case Study of LSD and Its Analogs
Applied Sciences February 25, 2023 Jelica Džodić, Dejan Milenković, Milica Marković et al. 27 citations
Theoretical methods accurately predict the infrared, NMR, UV-VIS, and mass spectra of lysergic acid diethylamide (LSD) when compared with experimental data. Optimizing the molecular structure at the M05-2X/6-311++G(d,p) level of theory yielded bond lengths within 0.0436 Å and bond angles within 2.70° of crystallographic data. The computed C=O stretching vibration differed from experimental by less than 11 cm⁻¹. Predicted 13C NMR chemical shifts correlated with experimental values at 0.999, with a mean absolute error of 2.0 ppm. The calculated ground-to-excited-state energy difference of 330 nm matched the observed UV-VIS band. This approach was validated against a seized-sample GC-MS spectrum and by computing NMR spectra of common LSD analogs, demonstrating its potential for characterizing novel psychedelics.