Dissociative recombination is a corner-stone reaction in the synthesis of interstellar molecules and plays an important role in the ionised layers of the atmospheres of the Earth, other planets, and their satellites. The studies of dissociative recombination reactions was for a long time dominated by afterglow techniques, and these techniques are used in improved versions also today, but the bulk of the relevant data have in recent years been produced at ion storage rings. We review briefly these different experimental techniques. As examples of recent developments in the field, we discuss in particular the dissociative recombination of , the role of dissociative recombination in the chemistry of hydrocarbons and sulphur compounds in the interstellar medium and planetary ionospheres, and the synthesis of interstellar methanol.

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.

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(2007). Experimental determination of dissociative recombination reaction pathways and absolute reaction cross-sections of CH2OH + , CD2OD + and CD2. Molecular Physics: Vol. 105, A Special Issue In Honour of John M. Brown, pp. 899-906.