Fig 4 . Energetic of the reaction between CI and HCOOH in water
cluster.
Among these pathways, three reactions are initiated through a cyclicTS1 with a barrier of 46.44 kcal/mol which is formed due to
1,4-insertion of CI to HCOOH. The TS1 then leads to one common
intermediate hydroperoxymethylformate INT (HPMF). The formation
of this INT is endergonic by 44.01 kcal/mol. This INT is
bifurcated to TS2 and TS3 at the energy level of 90.06
kcal/mol and 44.96 kcal/mol respectively. The TS2 yields highly
stabilized product (PROD-2 ) while TS3 gives a mixture
of radical product (PROD-3 ). Another mixture of product
(PROD-4 ) is found from TS3 via another TS5 .
The energy barrier associated with this path is very high. Another
reaction route involves proton abstraction from formic acid by CI to
generate an acid radical via TS4 with a low barrier of 10.17
kcal/mol.
3.5 Reactions between nitric acids and CI: For Nitric acid, as
the co-reactant for CI, three product formation pathways are shown in
Fig 5.