RT Journal Article
T1 Site-specific hydrogen-atom elimination in photoexcited alkyl radicals
A1 Chicharro Vacas, David
A1 Zanchet, Alexandre
A1 Bouallagui, Aymen
A1 Rubio-Lago, Luis
A1 García-Vela, Alberto
A1 Bañares Morcillo, Luis
A1 Marggi Poullaín, Sonia
AB A prompt site-specific hydrogen-atom elimination from the α-carbon atom (Cα) has been recently reported to occur in the photodissociation of ethyl radicals following excitation at 201 nm [Chicharro et al., Chem. Sci., 2019, 10, 6494]. Such pathway was accessed by means of an initial ro-vibrational energy characterizing the radicals produced by in situ photolysis of a precursor. Here, we present experimental evidence of a similar dynamics in a series of alkyl radicals (C2H5, n-C3H7, n-C4H9, and i-C3H7) containing the same reaction coordinate, but different extended structures. The main requirements for the site-specific mechanism in the studied radicals, namely a rather high content of internal energy prior to dissociation and the participation of vibrational promoting modes, is discussed in terms of the chemical structure of the radicals. The methyl deformation mode in all alkyl radicals along with the CH bending motion in i-C3H7 appear to promote this fast H-atom elimination channel. The photodissociation dynamics of the simplest unsaturated alkyl radical, the vinyl radical (C2H3), is also discussed, showing no signal of site-specific fast H-atom elimination. The results are complemented with high-level ab initio electronic structure calculations of potential energy curves of the vinyl radical, which are compared with those previously reported for the ethyl radical.
PB Royal Society of Chemistry
SN 1463-9076
YR 2021
FD 2021
LK https://hdl.handle.net/20.500.14352/92991
UL https://hdl.handle.net/20.500.14352/92991
LA eng
NO Chicharro, David V., et al. «Site-Specific Hydrogen-Atom Elimination in Photoexcited Alkyl Radicals». Physical Chemistry Chemical Physics, vol. 23, n.o 3, 2021, pp. 2458-68. https://doi.org/10.1039/D0CP05410K.
NO European Commission
NO Consejo Superior de Investigaciones Cientificas
NO Ministerio de Economía y Competitividad (España)
NO Ministerio de Ciencia e Innovación (España)
DS Docta Complutense
RD 7 abr 2025