Boron nitride nanotubes functionalized by a series of carbenes.

We systematically studied the structural, energetic and electronic properties of zigzag boron nitride nanotubes (BNNTs) functionalized by a class of substituted carbenes (CR(2)) where R = H, F, Cl, CH(3), CN and NO(2) on different absorption sites using density functional theory. For R = H, F and Cl, the open structure is preferred with a BNNT sidewall bond cleavage, while for R = CH(3) and CN, a competition between the open and closed cyclopropane-like three-membered ring (3MR) structure occurs. Interestingly, for R = NO(2) we find a novel double five-membered ring (5MR) structure with high reaction stability. This new structure cannot be found in BNNTs' alternative carbon nanotubes (CNTs). In addition, the electronic properties of BNNTs functionalized with carbenes are hardly changed for R = H, F, Cl, CH(3) and CN, but are significantly affected when R = NO(2) due to the heterocyclic double 5MR structure.