SYNTHESIS AND SINGLE-CRYSTAL X-RAY STRUCTURE OF A HIGHLY SYMMETRICAL C-60 DERIVATIVE, C60BR24

C60 and liquid bromine react to form C60Br24, a crystalline compound isolated as a bromine solvate, C60Br24(Br2)x. The x-ray crystal structure defines a new pattern of addition to the carbon skeleton that imparts a rare high symmetry. The parent C60 framework is recognizable in C60Br24, but sp3 carbons at sites of bromination distort the surface, affecting conformations of all of the hexagonal and pentagonal rings. Twenty-four bromine atoms envelop the carbon core, shielding the 18 remaining double bonds from addition. At 150-degrees to 200-degrees-C there is effectively quantitative reversion of C60Br24 to C60 and Br2.