Whereas the chemistry of fullerenes is well-established, the chemistry of single-walled carbon nanotubes (SWNTs) is a relatively unexplored field of research. Investigations into the bonding of moieties onto SWNTs are important because they provide fundamental structural insight into how nanoscale interactions occur. Hence, understanding SWNT chemistry becomes critical to rational, predictive manipulation of their properties. Among the strategies discussed include molecular metal complexation with SWNTs to control site-selective chemistry in these systems. In particular, work has been performed with Vaska's and Wilkinson's complexes to create functionalized adducts. Functionalization should offer a relatively simple means of tube solubilization and bundle exfoliation, and also allows for tubes to be utilized as recoverable catalyst supports. Solubilization of oxidized SWNTs has also been achieved through derivatization by using a functionalized organic crown ether. The resultant adduct yielded concentrations of dissolved nanotubes on the order of 1 g L(-1) in water and at elevated concentrations in a range of organic solvents, traditionally poor for SWNT manipulation. To further demonstrate chemical processability of SWNTs, we have subjected them to ozonolysis, followed by treatment with various independent reagents, to rationally generate a higher proportion of oxygenated functional groups on the nanotube surface. This protocol has been found to purify nanotubes. More importantly, the reaction sequence has been found to ozonize the sidewalls of these nanotubes. Finally, SWNTs have also been chemically modified with quantum dots and oxide nanocrystals. A composite heterostructure consisting of nanotubes joined to nanocrystals offers a unique opportunity to obtain desired physical, electronic, and chemical properties by adjusting synthetic conditions to tailor the size and structure of the individual sub-components, with implications for self-assembly.

The solubilization of oxidized carbon nanotubes has been achieved through derivatization using a functionalized organic crown ether. The resultant synthesized adduct yielded concentrations of dissolved nanotubes on the order of ∼1 g/L in water as well as in methanol, according to optical measurements. The nanotube−crown ether adduct can be readily redissolved in 10 different organic solvents at substantially high concentrations. Characterization of these solubilized adducts was performed with 1H NMR spectroscopy; 7Li NMR was also used to examine the ability of the crown ether's macrocyclic ring to bind Li+ ions. The solutions were further analyzed using UV−visible, photoluminescence, and FT-IR spectroscopies and were structurally characterized using atomic force microscopy (AFM) and transmission electron microscopy (TEM). Adduct formation likely results from a noncovalent chemical interaction between carboxylic groups on the oxidized tubes and amine moieties attached to the side chain of the crown ether derivative.

For Abstract see ChemInform Abstract in Full Text.

A new support structure for Co(III)salen catalysts has been developed to improve the kinetics for the hydrolytic kinetic resolution (HKR) of terminal epoxides. The new support consists of a copolymer composed of crosslinked salen-containing cyclic oligomers. Previous studies show that higher molecular weight cyclic oligomers are more active HKR catalysts than lower weight oligomers. The crosslinking reaction forms high molecular weight oligomers using a similar support structure and in significantly greater synthetic yield making the presented protocol synthetically more viable.