| Zdroj: |
Crane, S W, Ge, L, Cooper, G A, Carwithen, B P, Bain, M, Smith, J A, Hansen, C S & Ashfold, M N R 2021, ' Nonadiabatic coupling effects in the 800 nm strong field ionization induced Coulomb explosion of methyl iodide revealed by multi-mass velocity map imaging and ab initio simulation studies ', Journal of Physical Chemistry A, vol. 125, pp. 9594-9608 . https://doi.org/10.1021/acs.jpca.1c06346 |
| Popis: |
The Coulomb explosion (CE) of jet-cooled CH3I molecules using ultrashort (40 fs), nonresonant 805 nm strong-field ionization at three peak intensities (260, 650, and 1300 TW cm-2) has been investigated by multimass velocity map imaging, revealing an array of discernible fragment ions, that is, Iq+ (q ≤ 6), CHn+ (n = 0-3), CHn2+ (n = 0, 2), C3+, H+, H2+, and H3+. Complementary ab initio trajectory calculations of the CE of CH3IZ+ cations with Z ≤ 14 identify a range of behaviors. The CE of parent cations with Z = 2 and 3 can be well-described using a diatomic-like representation (as found previously) but the CE dynamics of all higher CH3IZ+ cations require a multidimensional description. The ab initio predicted Iq+ (q ≥ 3) fragment ion velocities are all at the high end of the velocity distributions measured for the corresponding Iq+ products. These mismatches are proposed as providing some of the clearest insights yet into the roles of nonadiabatic effects (and intramolecular charge transfer) in the CE of highly charged molecular cations. |
