Transition state spectroscopy of open shell systems: Angle-resolved photodetachment spectra for the adiabatic singlet states of OHF

Abstract

In this work three-dimensional potential energy surfaces of the first five singlet states of OHF are developed based on fits of more than 10000 highly accurate ab initio points. An approximate treatment is presented for the calculation of the anisotropy parameter describing the electron angular distribution photodetached from a molecular anion. This method is used to calculate the angle-resolved photoelectron spectra in the photodetachment of OHF −. The wave packet formed in the neutral OHF system is placed at the transition state region, and yields the formation of OH+F and HF+O products. The results are compared with the recent experimental measurements published by Neumark(Phys. Chem. Chem. Phys. 7, 433 (2005)). The intensity found at low electron kinetic energy including these 5 states and the three lower triplet states is found to be low. To analyze the effect of higher electronic states more excited 1 Σ − , 3 Σ + and 3 ∆ states are calculated at collinear geometry. The agreement with the experimental data improves, thus demonstrating that the correct simulation of the photodetachment spectrum at 213 nm involves at least 12 electronic states. All the structures of the experimental spectra are semiquantitatively reproduced finding an overall good agreement. It is concluded that the main problem of the simulation is in the intensity and anisotropy parameters. An alternative to their calculation would be to fit their values to reproduce the experimental results, but this would require to separate the contribution arising from different final electronic states.

(π*,σ*), (σ*,π*) and Rydberg Triplet Excited States of Hydrogen Peroxide and Other Molecules Bearing Two Adjacent Heteroatoms

“…Hypofluorous acid, HOF can be synthesized by controlled oxidation of water with molecular fluorine and is used as a selective oxidant. , A recent theoretical study had focused on a range of singlet excited states of HOF . At the CCSD(T)/aug-cc-pVQZ level of theory, its first excited triplet (A″) state of (π*,σ*) type is calculated to be 42.2 kcal mol –1 above the singlet ground state.…”

An accurate study of the dynamics of the C+OH reaction on the second excited 14A″ potential energy surface

“…The astrophysical interest of reactions between free radicals has motivated an ample list of recent studies of collisions between open-shell atoms such as C( 3 P), [1][2][3][4][5][6][7] N( 4 S), [8][9][10] F( 2 P), [11][12][13][14] O( 3 P), [15][16][17][18] or S( 3 P) (Refs. 19 and 20) with the hydroxyl radical OH( 2 ).…”

Quantum mechanics and quasiclassical study of the H/D+FO → OH/OD+F, HF/DF+O reactions: Chemical stereodynamics

“…The calculation employed the three recent potential energy surfaces of Gómez-Carrasco and coworkers. [21][22][23][24] As shown in Ref. 21, all the three considered electronic states, i.e., the singlet 1 1 A 0 and the triplet 1 3 A 0 and 1 3 A 00 states correlate asymptotically and adiabatically to the reactant H( 2 S)1FO( 2 P) and the product OH( 2 P)1F( 2 P) channels, and reactions via the two triplet states each will lead to the O( 3 P)1HF( 1 S 1 ) product channel, whereas that via the singlet state lead to the O( 1 D)1HF( 1 S 1 ) formation.…”