Synthesis and structural characterization of single-walled carbon nanotubes functionalized with fluorinated phosphonate analogues of phenylglycine, as promising materials for synthetic and biomedical applications

Abstract

Through chemical functionalization the prerequisites for possible applications of such nanostructures as single-walled carbon nanotubes (SWCNTs) are established. In this study, modifications of SWCNTs by fluorinated phosphonate analogue of phenylglycine, compound belonging to important group of natural amino acid mimetics, using two approaches are presented. The first one was based on noncovalent functionalization of SWCNTs with the phosphono-perfluorophenylglycine analogue. In the second approach, SWCNTs were covalently bonded to the fluorinated α-aminophosphonates in one-step or multi-step reactions. The investigation of the functionalization effect on the dispersibility, thermal properties and the structure of SWCNTs was performed by using of X-Ray spectroscopy, TGA and Raman spectroscopy. Both approaches indicated promising methods for fast and efficient modification of carbon nanotubes (CNTs) also with other representatives of previously synthesized fluorinated aminophosphonates. Functionalized with such compounds CNTs can constitute materials for synthetic and biomedical applications. Due to their biological activity and structural analogy to corresponding α-amino acids, fluorinated α-aminophosphonates provide an important source for drug discovery. Therefore functionalization of SWCNTs with such molecules can provide an important platforms for drug delivery applications. Due to the presence of perfluorinated phenyl rings various nucleophiles can be introduced by nucleophilic aromatic substitution reactions to the functionalized SWCNTs leading to obtaining completely new materials.