2,9-Diiodo-hexa-cyclo-[9.3.1.12,6.14,8.1 9,13.01,8]octa-deca-ne

The title compound, C18H24I2, has an adamantanoid structure with tetra-hedral cages having four C atoms lying on the same plane [(I-)C-C-C-C(-I) torsion angle = 0°]. The plane is extended by the two I atoms, each having a deviation of 1.0 (6) Å [C-C-C-I torsion angle = 178.9 (4)°]. The central C-C bond connecting the two quaternary carbons seems enlarged [1.593 (9) Å] in comparison to the corresponding bond in [2]diadamantane [1.554 (3) Å]. This is attributed to the presence of the electronegative I atoms, which affect inductively the C atoms of the four-C-atom plane, making the central C-C bond weaker.