Theoretical study of BN _4: Potential precursors of high energy density materials (HEDMs)

摘要

Ab initio (MP2) and density functional theory (DFT) methods were used to examine nine isomers of the doublet BN _4 species with the 6-311 + G(d) basis set. To our knowledge, these nine structures are all first reported here. Energy analysis indicates that the C _(2v) branched structure is the global minimum of potential energy surface. Research results show that the C _(2v) branched, the cis-linear, the C _(4v) pyramidal, and the C _S five-membered ring structures are likely to be stable and to be observed experimentally. Among these four kinetically stable species, the last three are suitable to be used as potential precursors of HEDMs due to their high dissociation energies. However, the C _(2v) bent, the trans-linear, the D _2 bicyclic, the C _(2v) fourmembered ring, and the C _(2v) cage structures are kinetically unstable due to their low dissociation or isomerization barriers. Two synthesis pathways of the C _(2v) branched isomer were located. It seems more feasible to synthesize this species by linear NBN and N _2.