An Atom‐Economical Approach to Functionalized Single‐Walled Carbon Nanotubes: Reaction with Disulfides

Abstract

Owing to their unique structure, thermal stability, and mechanical and electronic properties, single-walled carbon nanotubes (SWCNTs) have been a subject of continuous and intense interest. However, various applications in many fields, such as molecular electronics, solar cells, and nanomedicine, often require the development of reproducible protocols for the chemical modification of SWCNTs. In fact, one of the main drawbacks of the use of SWCNTs is their tendency to aggregate and intrinsic poor solubility, which prevent their manipulation and limit their potential. To date, several methods have been described for the chemical functionalization of SWCNTs; however, new versatile and reliable methods are still needed.We focused our attention on disulfides, which are a very useful family of compounds owing to the presence of the flexible S S bond. Disulfides can be prepared readily from the corresponding thiols; thus, a wide range of substrates are accessible. In this study, we used very mild and reproducible conditions for the production of a wide variety of functionalized SWCNTs (f-SWCNT). Pristine HiPco SWCNTs (p-SWCNTs, prepared with high-pressure carbon monoxide, HiPco) were treated with disulfides in deoxygenated toluene at reflux (Scheme 1). The reaction with diphenyl disulfide was monitored for 48 h by