Dissociative recombination of fully deuterated protonated acetonitrile, CD3CND+: product branching fractions, absolute cross section and thermal rate coefficient

Abstract

The dissociative recombination of fully deuterated protonated acetonitrile, CD₃CND⁺, has been investigated at the CRYRING heavy ion storage ring, located at the Manne Siegbahn Laboratory, Stockholm, Sweden. Branching fractions were measured at ∼0 eV relative collision energy between the ions and the electrons and in 65% of the DR events there was no rupture of bonds between heavy atoms. In the remaining 35%, one of the bonds between the heavy atoms was broken. The DR cross-section was measured between ∼0 eV and 1 eV relative collision energy. In the energy region between 1 meV and 0.1 eV the cross section data were best fitted by the expression σ = 7.37 × 10⁻¹⁶ (E/eV)^−1.23 cm², whereas σ = 4.12 × 10⁻¹⁶ (E/eV)^−1.46 cm² was the best fit for the energy region between 0.1 and 1.0 eV. From the cross section a thermal rate coefficient of α(T) = 8.13 × 10⁻⁷ (T/300)^−0.69 cm³ s⁻¹ was deduced.