Structures of Se chains encapsulated in single-walled carbon nanotubes

In this study, the structures of two Se chains confined inside single-walled carbon nanotubes (SWCNTs), which were denoted as Se@SWCNT, were investigated by extended X-ray absorption fine structure analysis and transmission electron microscopy. The Se chains were linear and parallel to each other in the SWCNTs. The covalent bond length of Se@SWCNT was shorter than that of trigonal Se (t-Se), whereas the force constant was larger, thereby suggesting that the covalent bond was stronger for Se@SWCNT than that for t-Se. The interchain interaction originated from the overlap of lone-pair and antibonding orbitals on adjacent chains, so the disappearance of the overlap in the encapsulated Se chains strengthened the covalent bonds.

Automated summary

This study investigated the structures of two Se chains confined inside single-walled carbon nanotubes (SWCNTs), revealing that the chains were linear and parallel. The covalent bond between Se and SWCNT was found to be stronger than that between Se and trigonal Se (t-Se). The interaction between chains was attributed to the overlap of electronic orbitals, and the disappearance of this overlap in the encapsulated Se chains enhanced the covalent bonds.