Solubilization of single-walled carbon nanotubes by supramolecular complexes of barbituric acid and triaminopyrimidines

In this letter, we report that single-walled carbon nanotubes (SWNTs) can be dissolved in organic solvents through the formation of admixtures with barbituric acid.triaminopyrimidine (BA.TP) complexes using mechanochemical high-speed vibration milling (HSVM) and sonication methods. In contrast, neither BA nor TP alone were capable of solubilizing SWNTs. Moreover, the glutarimide (GI).TP complex was also found to be incapable of solubilizing SWNTs because the two carbonyl groups and one imino group of GI are located on only one side of the molecule such that the GI.TP complex cannot form the desired hydrogen-bonding network. These results strongly suggest that the formation of a hydrogen-bonding network makes possible the formation of multipoint interactions with the surfaces of the SWNTs.