Figure 7: Detailed optimized structures for 2-, 3-, 5-, and 7-diketone-attached nanotubes. We labeled six-membered rings that will be attached by oxygen pairs. Values in Å indicate the optimized CC separations, created by diketone formation. Dihedral angles of the a, b, c, and d carbon atoms are defined. Note that the carbon atoms labeled by “b” are the binding site for ketone formation.