Rule-cracking bucky eggs

Unusual egg-shaped fullerene molecules contain three fused pentagons, unlike conventional fullerenes, according to Chinese chemists. The new compounds, made by Yuan-Zhi Tan of Xiamen University, and colleagues have a bulging ovoid shape that could help explain some of the mysteries about fullerene structures. Triply fused pentagons of carbon atoms could be a basic subunit of fullerene molecules, but violate the so-called isolated pentagon rule. Tan and colleagues used X-ray crystallography to show that they broke the rule.