C60: definitely a beauty, maybe a beast.

[C.sub.60]: Definitely a beauty, maybe a beast

Since last August, physics graduate student Lowell D. Lamb and his co-workers at the University of Arizona in Tucson have donned gloves and masks when working with chemistry's latest darling, a soccerball-shaped molecule known as buckminsterfullerene. That's when Henry K. Hall Jr., a chemist at the university, alerted them to health hazards that may lurk in the 60-carbon beauty.

No one has reported ill effects from buckminsterfullerene, but Hall and others urge researchers to proceed with caution. If biologists were to happen upon a new animal species with teeth and claws, they would take precautions even though the animal might turn out to be a pussycat. The same should hold for scientists probing new chemical species, Hall warns.

By some estimates, hundreds of researchers now spend at least part of their time studying [C.sub.60], its molecular cousins such as [C.sub.70] and [C.sub.84], and the solid materials, called fullerites, into which these cage-like molecules assemble (SN: 12/8/90, p.357). The fullerites join diamond and graphite as the third material form of carbon atoms.

But the same structural symmetries and physical oddities that render these celebrity chemicals so intriguing may represent the molecular equivalent of teeth and claws, researchers are finding.

Robert Whetten of the University of California, Los Angeles, and his co-workers have been outspoken about such possibilities. In the Jan. 9 JOURNAL OF PHYSICAL CHEMISTRY, they report that [C.sub.60], in the presence of light, efficiently transforms oxygen molecules into a so-called singlet state, an especially reactive form that can sabotage biochemical harmonies underlying the health of cells and tissues. The researchers do not yet know if [C.sub.60] actually can initiate these processes under physiological conditions, Whetten notes. Besides pegging buckminsterfullerene as a potential health threat, the findings show how the molecule's electrons harness and shunt light-energy as [C.sub.60] interacts with nearby molecules.

"The degree to which [C.sub.60] is present in the environment becomes a very important question," the UCLA researchers state in their paper. That the synthesis of [C.sub.60] yields fine powders only heightens their concern. "We feel it is important to warn researchers to take precautions against skin contact and breathing of the dusts, at least until the physiological properties of the material have been better characterized," warn Whetten, Francois N. Diederich and Christopher S. Foote of UCLA, and Fred Wudl of the University of California, Santa Barbara, in a letter in the Dec. 17, 1990 CHEMICAL & ENGINEERING NEWS.