Chlorination-promoted Transformation of Isolated Pentagon Rule C into Fused-pentagons- and Heptagons-containing Fullerenes.

Cage transformations in fullerenes are rare phenomena which are still not fully understood. We report the first skeletal transformation of an Isolated-Pentagon-Rule (IPR) isomer of C fullerene upon high-temperature chlorination which proceeds by six-step Stone-Wales rearrangements affording non-IPR, non-classical (NC) C (NC2)Cl with two cage heptagons, six pairs of fused pentagons, and an unprecedented loop-like chlorination pattern. The following loss of a C unit results in C (NC3)Cl containing three cage heptagons.