Chemical functionalization of boron nitride nanotube via the 1,3-dipolar cycloaddition reaction of azomethine ylide: a quantum chemical study

The first principle exploration at the M05-2X/6-31+G(d,p) level was performed to investigate the chemical functionalizations of (6,0) zigzag single-walled BNNT via the 1,3-dipolar cycloaddition reaction of azomethine ylide. Two types of functionalized BNNTs (D and A complexes) were found in the reaction between 2-methoxy-N,N-dimethylethanamine (MDE) and BNNT. It is energetically favorable for the MDE functional group to interact with the B–N bonds slanted to the tube axis (in D-type complexes). The configuration of the lowest minimum energy corresponds to geometry D1, which the functional group interacts with the end of N-terminated BNNT. The results show that the functionalization of BNNT by MDE functional group is accompanied by a decrease in the band gap, so that this decrease in A complexes is greater than that in the corresponding D ones. Also, the results obtained by natural bond orbital analysis showed that the charge transfer occurs from nanotube to MDE functional group.