%0 Journal Article
%T Impact of the Acetyl Group on Cysteine: A Study of N-Acetyl-Cysteine through Rotational Spectroscopy.
%A Mato S
%A Municio S
%A Alonso JL
%A Alonso ER
%A León I
%J Chemphyschem
%V 25
%N 15
%D 2024 Aug 1
%M 38703034
%F 3.52
%R 10.1002/cphc.202400191
%X Herein, we report a spectroscopic study of N-acetyl-L-cysteine, an important antioxidant drug, using Fourier-transform microwave techniques and in isolated conditions. Two conformers are observed, where most stable structure adopts a cis disposition, and the second conformer has a lower abundance and adopts a trans disposition. The rotational constants and the barriers to methyl internal rotation are determined for each conformer, allowing a precise conformation identification. The results show that the cis form adopts an identical structure in the crystal, solution, and gas phases. Additionally, the structures are contrasted against those of cysteine.