Evidence for Higher Reactivity of B₂. Theoretical Studies of Insertions of B₂ and B into Methane and Water

The insertions of B 2 and B into methane and water have been chosen as models to study the reactivities of atom dimers vs bare atoms. At our highest theoretical level (B3LYP/6-311++G(3df,2p)//B3LYP/6-311++G(2d,p)), the activation energies for B 2 insertions into methane and water are predicted to be 4.1 and −6.7 kcal/mol, respectively, while the values increase to 16.2 and 0.0 kcal/mol for insertions of B into two substrates, which shows directly that B 2 have a higher reactivity than B in inserting into the two substrates. In addition, two new species CH 3 BH(B) and HOBH(B) are theoretically predicted.