Reactivities of the Prism‐Shaped Diamondoids [1(2)3]Tetramantane and [12312]Hexamantane (Cyclohexamantane)

Functionalized nanodiamonds: Various functional groups have been incorporated into the structures of the naturally occurring diamondoids [1(2)3]tetramantane and [12312]hexamantane (cyclohexamantane), which represent hydrogen-terminated prism-shaped nanodiamonds (see picture). The attachment points define the use of these diamond-like molecules as geometric building blocks for a variety of applications. Various functional groups have been incorporated into the structures of the naturally occurring diamondoids [1(2)3]tetramantane and [12312]hexamantane (cyclohexamantane), which represent hydrogen-terminated prism-shaped nanodiamonds. The selectivities of the CH substitutions in [1(2)3]tetramantane depend on the reagent employed and give products substituted at either central (through bromination) or peripheral (through nitroxylation and photo-oxidation) positions. The hydrogen-coupled electron-transfer mechanism of CH nitroxylation with the model electrophile NO2+⋅⋅⋅HNO3 was verified computationally at the B3PW91 and MP2 levels of theory by utilizing the 6-31G(d) and cc-pVDZ basis sets. The thermodynamically controlled nitroxylation/isomerization of [1(2)3]tetramantane allows the preparation of peripherally trisubstituted derivatives, which were transformed into tripod-like nanodiamond building blocks. The bromination of cyclohexamantane selectively gives the 2-bromo derivative, reproducing the chemical behavior of the {111} surface of the hydrogen-terminated diamond.