Theoretical exploration on the characterization of btrichloroborazine and its derivatives

The B-trichloroborazine (TCB) and its derivatives with alkyl amine borazine are the effective precursor to the preparation of hexagonal BN (h-BN). On account of the specific structures of TCB and its derivatives will make some influences on the preparation reactions, in this work, by means of density functional theory, we perform a theoretical estimation of the reaction characterization of TCB and its derivatives. The results show that the order of the Wiberg bond index is Cl>H>NHCH₃>N(CH₃) ₂ (1.081>1.002>0.9874>0.9432). Furthermore, the gap energy of frontier orbit of TCB, Cl₂[N(CH₃)₂]B ₃N₃H₃, Cl[N(CH₃)₂]2B ₃N₃H₃ and [N(CH₃) ₂]3B₃N3H₃ is 784.2 KJ/mol, 666.5 KJ/mol, 695.8 KJ/mol and 674.2 KJ/mol. It is shown that the reactivity of TCB and its substituents are in the following order: TCB < Cl[N(CH₃)2]2B ₃N₃H₃ < [N(CH₃)2] ₃B3N₃H₃ < Cl₂[N(CH ₃)₂]B₃N₃H₃. All the results demonstrate that the one alkyl amine derivative has the better reaction activity than TCB and the other two derivatives. Then we consider the influences on the reaction induced by the N(CH₃)₂ and NHCH ₃ in the TCB derivatives. It is verified that the gap energy of the substitution reaction on NHCH₃ derivatives is greater than that on the N(CH₃)₂ derivatives, demonstrating that the derivatives of N(CH₃)₂ has a higher reaction activity than that of NHCH₃. This work should be of some significance for estimating the reaction activity and product in the preparation of h-BN.