Researchers from the Massachusetts General Hospital in Boston (USA) have announced that hydrogen sulfide (sulphide) gas, H₂S, can induce a state of suspended animation in mice while maintaining normal blood pressure. It is hoped that this result eventually will help in the treatment critically-ill patients. This result was presented at the American Physiological Society conference, "Comparative Physiology 2006: Integrating Diversity," in Virginia Beach, Virginai, USA, October 2006.

Hydrogen sulfide (sulphide) gas, sometimes called sewer gas, produces a noxious odour often described as a rotten egg smell. This highly toxic gas occurs naturally in swamps, some springs, and volcanoes.

An egg-shaped fullerene, or "buckyball egg" has been made and characterized by chemists in America at UC Davis (California), Virginia Tech, and Emory and Henry College in Virginia. They were trying to encapsulate terbium atoms within fullerenes but instead encapsulated terbium nitride within an egg-shaped fullerene.

The compound Tb₃N@C₈₄ was synthesized using an arc-discharge generator by vaporizing composite graphite rods containing a mixture of Tb₄O₇, graphite, and iron nitride as catalyst in a low-pressure He/N₂atmosphere. This gave a complex mixture of products and chromatography gave seven terbium-containing fractions, the fourth fraction of which contained two isomers of Tb₃N@C₈₄. Crystallographc studies show the compound from one angle in particular seems very egg shaped! Remarkable! The Tb₃N unit is clearly visible (terbium in green and nitrogen in blue).

Until the publication of this work it was normally accepted that no two pentagons can touch in a fullerene and are always surrounded by hexagons. However in this case there are two pentagons (the 8 atoms at the pointy part of the egg at the top of the attached image) linked as a bent pentalene fragment.

References

1. "Tb₃N@C₈₄: An Improbable, Egg-Shaped Endohedral Fullerene that Violates the Isolated Pentagon Rule", C.M. Beavers, T. Zuo, J.C. Duchamp, K. Harich, H.C. Dorn, M.M. Olmstead, and A.L. Balch, J. Am. Chem. Soc., 2006, 128, 11352.
2. UC Davis News Service