Unimolecular and bimolecular reactions of state selected HCl+ ions formed via the R(1) pump line of the f3Δ2←1Σ+ REMPI spectrum
Abstract
The
properties of HCl+ ions formed in the vibronic ground state 2Π3/2 (″
= 0)
ia the R(1) pump line of the f3Δ2←1Σ+ REMPI spectrum have been investigated. In the first experiment the rotational state distribution of these
ions has been determined by photoexcitation into the A2Σ+(
′
= 7) state, which can predissociate. 73% of
the HCl+ ions are found in the N″
= 0 state, 23% in the N″
= 1 and 4% in the N″
= 2 state. This experiment also yields the spectroscopic parameters of the A2Σ+(
′
= 7) state and information on the rotational dependence of the predissociation lifetimes of this state. The threshold for predissociation occurs between the N′
= 0, J′
= 1/2 and the N′
= 1, J′
= 1/2 state, leading to a new dissociation energy of the HCl+
ion of D0
= 37536.5 cm−1±5 cm−1. In the second experiment these state-selected HCl+ ions are investigated in an ion–molecule reaction with carbon monoxide. In
this reaction very efficient proton transfer leads to the formation of HCO+ with a rate constant close to the Langevin limit.