We have investigated the dissociative recombination (DR) of the
C6D6+
and C6D7+
ions using the CRYRING heavy-ion storage ring at Stockholm University, Sweden. The
dissociative recombination branching ratios were determined at minimal collision energy,
showing that the DR of both ions was dominated by pathways keeping the carbon atoms
together in one product. The absolute reaction cross sections for the titular ions are
best fitted by σ(Ecm [eV]) = 1.3 ± 0.4 × 10-15
(Ecm [eV])−1.19 ± 0.02 cm2
(C6D6+)
and σ(Ecm [eV]) = 1.1 ± 0.3 ×
10-15(Ecm [eV])−1.33 ± 0.02 cm2
(C6D7+)
in the intervals 3-300 meV and 3-200 meV respectively. The thermal rate constants of the
titular reactions are best described by:
k(T) = 1.3 ± 0.4 × 10-6(T/300)−0.69 ± 0.02
cm3s-1 for C6D6+
and k(T) = 2.0 ± 0.6 × 10-6 (T/300)−0.83 ± 0.02
cm3s-1 for C6D7+.
These expressions correlates well with earlier flowing afterglow studies on the same
process.