X‐Ray Crystal Structure of the 2‐Phenyladamant‐2‐yl Cation

The crystal structure of the Sb 2 F 11 salt of the 2‐phenyladamant‐2‐yl cation, 1 · Sb 2 F 11 , was determined at 183 K ( P 2 1 / c , R 1 = 0.0652, σ(CC) = 0.02 Å), because earlier published results indicated a charge delocalization from the cationic C(2) into the σ framework (CC hyperconjugation) and a bending of the C(2) bridge. In the structure of 1 , a displacement of the C(2) bridge by 7.8(12)° from the symmetrical position and CC bond‐length deviations from expectation values were found which are in agreement with preferential CC hyperconjugation on one face of C(2). The interactions of 1 with two Sb 2 F 11 counterions nearest to C(2) also indicate different behaviour of the two faces of C(2). The benzylic resonance in 1 is confirmed.