Two-dimensional (2+n) REMPI of CH(3)Br: photodissociation channels via Rydberg states.
(2+n) resonance enhanced multiphoton ionization (REMPI) spectra of CH(3)Br for the masses H(+), CH(m)(+), (i)Br(+), H(i)Br(+), and CH(m)(i)Br(+) (m = 0-3; i = 79, 81) have been recorded in the 66 000-81 000 cm(-1) resonance energy range. Signals due to resonance transitions from the zero vibrational energy level of the ground state CH(3)Br to a number of Rydberg states [Ω(c)]nl;ω (Ω(c) = 3/2, 1/2; ω = 0, 2; l = 1(p), 2(d)) and various vibrational states were identified. C((3)P) and C*((1)D) atom and HBr intermediate production, detected by (2+1) REMPI, most probably is due to photodissociation of CH(3)Br via two-photon excitations to Rydberg states followed by an unusual breaking of four bonds and formation of two bonds to give the fragments H(2) + C/C* + HBr prior to ionization. This observation is supported by REMPI observations as well as potential energy surface (PES) ab initio calculations. Bromine atom production by photodissociation channels via two-photon excitation to Rydberg states is identified by detecting bromine atom (2+1) REMPI.
Kvaran
Agúst
A
Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavík, Iceland. agust@hi.is
Wang
Huasheng
H
Matthíasson
Kristján
K
Bodi
Andras
A
D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D013058:Mass Spectrometry; D010777:Photochemistry; D011789:Quantum Theory; D013057:Spectrum Analysis
D006842:Hydrocarbons, Brominated; C005218:methyl bromide