Finally, another possibility for branching exists in C (path E), provided that an OH radical is present. The spin crossover C MECP that takes place has a barrier of ΔG ‡ = 15.1 kcal/mol and results in Diol K (ΔG = -36.1kcal/mol), the K + salt analogue of Diol. This structure can then react in the presence of water to result in the formation of Diol with a barrier for this reaction step of ΔG ‡ = 17.2 kcal/mol (TS C-Diol ). Afterwards the Diol intermediate re-enters path D via TS Diol-F (scrambling) to yield F1 and F2 with equal probability. Many alternate paths towards the product F starting from each intermediate were attempted, but the transition states were found to be either very high or calculations converged to previously known intermediates. Consequently, the previously described pathways are, to our knowledge, the only ones thermodynamically feasible. The termination of the reaction can happen via paths C, D or E, as well as through the decomposition of H2O2. This can be generated in path A, or by the combination of two OH radicals formed via path B.