RT Journal Article
T1 Photodissociation dynamics of methylamine in the blue edge of the <i>A</i>-band. II. The NH2 + CH3 channel
A1 Bañares Morcillo, Luis
A1 Marggi Poullaín, Sonia
A1 Recio Ibáñez, Pedro
A1 Cachón, Javier
A1 Zanchet, Alexandre
AB The photodissociation dynamics leading to the C–N bond cleavage in methylamine (CH3NH2) are investigated upon photoexcitation in the blue edge of the first absorption A-band, in the 198–204 nm range. Velocity map images of the generated methyl (CH3) fragment detected in specific vibrational modes, i.e., ν = 0, ν1 = 1, and ν2 = 1, through resonance enhanced multiphoton ionization, are presented along with the corresponding translational energy distributions and the angular analysis. The experimental results are complemented by high-level ab initio calculations of potential energy curves as a function of the C–N bond distance. While a similar single Boltzmann-type contribution is observed in all the translational energy distributions measured, the speed-dependent anisotropy parameter obtained through the angular analysis reveals the presence of two different mechanisms. Prompt dissociation through the conical intersection between the A1A' first excited state and the ground state located in the exit channel is, indeed, revealed as a minor channel. In contrast, slow dissociation on the ground state, presumably from frustrated N–H bond cleavage trajectories, constitutes the major reaction pathway leading to the methyl formation.
PB AIP Publishing
SN 0021-9606
SN 1089-7690
YR 2023
FD 2023-08-09
LK https://hdl.handle.net/20.500.14352/131407
UL https://hdl.handle.net/20.500.14352/131407
LA eng
NO Javier Cachón, Pedro Recio, Alexandre Zanchet, Sonia Marggi Poullain, Luis Bañares; Photodissociation dynamics of methylamine in the blue edge of the A-band. II. The NH2 + CH3 channel. J. Chem. Phys. 14 August 2023; 159 (6): 064302. https://doi.org/10.1063/5.0159855
NO Submitted: 27 May 2023, Accepted: 20 July 2023, Published Online: 9 August 2023.P.R. is grateful to Universidad Complutense de Madrid (UCM) for a Margarita Salas postdoctoral contract. J.C. acknowledges the financial support from the Spanish Ministry of Science and Innovation under the FPI predoctoral program. This research was carried out within the Unidad Asociada Química Física Molecular between the Departamento de Química Física of Universidad Complutense de Madrid and CSIC. This work was funded by Grant Nos. PGC2018-096444-B-I00, PID2019-107115GB-C21, PID2021-122839NB-I00, and PID2021-122549NB-C21 from the Spanish Ministry of Science and Innovation. The financial support (Grant No. PR27/21-010) provided by the Madrid Government (Comunidad de Madrid, Spain) under the Multiannual Agreement with Universidad Complutense de Madrid in the line Research Incentive for Young Ph.D.s, in the context of the V PRICIT (Regional Programme of Research and Technological Innovation), is also acknowledged. The facilities provided by the Centro de Láseres Ultrarrápidos at Universidad Complutense de Madrid are gratefully acknowledged.
NO Universidad Complutense de Madrid (UCM)
NO Spanish Ministry of Science and Innovation
NO Madrid Government (Comunidad de Madrid, Spain)
DS Docta Complutense
RD 8 jun 2026