<i>ortho</i>-Substituted Aryldiazonium Design for the Defect Configuration-Controlled Photoluminescent Functionalization of Chiral Single-Walled Carbon Nanotubes.

Yu, Boda; Naka, Sadahito; Aoki, Haruka; Kato, Koichiro; Yamashita, Daiki; Fujii, Shun; Kato, Yuichiro K; Fujigaya, Tsuyohiko et al. · ACS Nano · 2022

basic_science · Level V

Where this comes from

Abstract

Defect functionalization of single-walled carbon nanotubes (SWCNTs) by chemical modification is a promising strategy for near-infrared photoluminescence (NIR PL) generation at >1000 nm, which has advanced telecom and bio/medical applications. The covalent attachment of molecular reagents generates sp<sup>3</sup>-carbon defects in the sp<sup>2</sup>-carbon lattice of SWCNTs with bright red-shifted PL generation. Although the positional difference between proximal sp<sup>3</sup>-carbon defects, labeled as the defect binding configuration, can dominate NIR PL properties, the defect arrangement chemistry remains unexplored. Here, aryldiazonium reagents with π-conjugated <i>ortho</i>-substituents (phenyl and acetylene groups) were developed to introduce molecular interactions with nanotube sidewalls into the defect-formation chemical reaction. The functionalized chiral SWCNTs selectively emitted single defect PL in the wavelength range of ∼1230-1270 nm for (6,5) tubes, indicating the formation of an atypical binding configuration, different from those exhibited by typical aryl- or alkyl-functionalized chiral tubes emitting ∼1150 nm PL. Moreover, the acetylene-based substituent design enabled PL brightening and a subsequent molecular modification of the doped sites using click chemistry.