Structure and transformations of diamantane radical cation: Theory and experiment

Quantum chemical calculations at the DFT (B3LYP-D3, M06-2X, B3PW91) and MP2 levels of theory consistently showed that diamantane radical cation in the gas phase has D 3 d symmetry with two elongated apical C-H bonds. Its complexation with a nucleophilic solvent stabilizes alternative C s structure with two elongated medial C-H bonds. This is in agreement with the behavior of diamantane under anodic oxidation conditions, which leads to predominant formation of the medial substitution product.