DFT Study of Interactions of Carbenes with Boron Nitride Nanotubes

Single-walled boron nitride nanotubes are chosen as model reactants, and (10,0) and (6,6) are chosen as representatives of armchair and zigzag nanotubes, respectively, to study the interaction of carbenes of the type :CX2. It is found that, contrary to the case of carbon nanotubes, boron nitride tubes, particularly armchair BNNTs, do not show a propensity for cyclopropane ring formation. The SWBNNT (10,0) system with :CH2 forms an insertion product. Mulliken population analysis is also done to ascertain the charge distribution in the final product and to emphasize the effect of electronegativity on the functionalizations. The band gaps are also analysed and it is noted that the sidewall functionalisations by carbenes have a profound effect on the electronic properties of boron nitride nanotubes. The carbene adopts a triplet state for zigzag BNNTs, but remains in the singlet state for the armchair BNNTs. The bandgap is found to decrease with increasing tube diameter.