Photolysis of 1,2-dithiane (1) in acetonitrile with single walled carbon nanotubes (SWCNTs) was earlier reported to form thiol-functionalized SWCNTs via the butane-1,4-dithiyl diradical (2). The present study shows that 2 instead undergoes a facile rearrangement to thiophane-2-thiol (6). This photoreaction is clean, rapid, and irreversible under 313 nm irradiation. The secondary photolysis of 6 with SWCNTs at a shorter wavelength (254 nm) leads to 2-thiophanyl radicals 8, which derivatize SWCNTs by covalent attachment. Pyrolysis of the resulting “sulfurized SWCNTs” affords a mixture of organosulfur compounds, including thiophene formed by dehydrogenation. An unknown additional mechanism causes high TGA weight loss and a large incorporation of sulfur.

Pristine, individualized single-walled carbon nanotubes (SWCNTs) have been noncovalently captured within PEG-terminated block copolymer amphiphiles. Two cross-linkable amphiphiles were evaluated: polyethylene glycol-polyacrylic acid-polystyrene (PEG-PAA-PS) and polyethylene glycol-polybutadiene (PEG-PB). The resulting self-assembled PEG-PAA-PS structures, called PEG-eggs, are freely soluble in water and stable in physiological media. SWCNTs in PEG-eggs retain their intrinsic near-infrared fluorescence, resist exchange with serum proteins, and are non-cytotoxic to mouse macrophage and human renal cells based on in vitro viability assays.