Investigation of organic monoradicals reactivity using surface-enhanced Raman spectroscopy

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2022-10, Vol.278, p.121312, Article 121312
• Main Authors: Gutowski, Łukasz, Liszewska, Malwina, Bartosewicz, Bartosz, Budner, Bogusław, Weyher, Jan L., Jankiewicz, Bartłomiej J.
• Format: Article
• Language: English
• Subjects: Organic monoradicals; Reactive intermediates; Reactivity; Self-assembled monolayer; SERS; SERS substrates
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2022.121312

[Display omitted] •New approach to stimulate molecular transformations on the metallic nanostructures.•SERS and SAM approaches were used to investigate reactivity of organic monoradicals.•Efficiency of monoradical generation is dependent on the structure of its precursor.•SERS substrate and experimental conditions strongly influence the obtained results. Surface-enhanced Raman spectroscopy (SERS) and self-assembled monolayer (SAM) approaches were used to investigate the reactions of organic monoradicals with methanol. An attempt was made to generate monoradicals from thiophenols and phenylmethanethiols substituted with bromine, iodine, and nitro groups by irradiation with UV light. Monolayers of radical precursors were deposited on SERS substrates, which were then immersed in methanol and irradiated for 1 and/or 3, 6, 12 and 24 h in a UV photochemical reactor. Pre- and postreaction SERS spectra were obtained by using a confocal Raman microscope and compared with the spectra of expected products of the radical reaction with methanol. Our studies have shown that the efficiency of monoradical generation is highly dependent on the chemical structure of the precursor. In addition, it is shown that both the SERS substrate and experimental conditions used strongly influence the obtained results.