Synthesis and Single-Crystal X-ray Structure of a Highly Symmetrical C 60 Derivative, C 60 Br 24

Abstract

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° to 200°C there is effectively quantitative reversion of C₆₀Br₂₄ to C₆₀ and Br₂.