Making Chicken Wire of Molecular Size
Amato, I., Science News
Making chicken wire of molecular size
Nine years ago, chemist Orville L. Chapman had one question in mind when he traveled to Germany on a fellowship: "If God would give me one molecule to make, what would that molecule be?" His goal ever since: to build an 80-carbon molecular ball, a lesser-known member of a recently recognized class of spherical molecules called fullerenes.
In Honolulu this week, at the International Chemical Congress of Pacific Basin Societies, Chapman reported making molecular-scale "chicken wire" and other exotic materials, all of which have recently emerged from his efforts to develop a step-by-step laboratory method for building his chosen molecule.
Most famous of the fullerenes is buckminsterfullerene, a 60-carbon, soccer-ball-shaped molecule whose interlocking hexagonal and pentagonal facets resemble the geodesic domes designed by engineering visionary R. Buckminster Fuller. For about five years, researchers have been assembling evidence that the diminutive soccer balls and other carbon spheres form in the sooty wake of laserzapped graphite. The remarkably stable C-60 molecule forms in almost any soot-producing environment, notes fullerene chemist Richard E. Smalley of Rice University in Houston. It may even populate interstellar space (SN: 1/28/89, p.56).
Rather than relying on laser blasts, which produce fullerenes through unknown mechanisms, Chapman aims to design sequences of chemical reactions for methodically assembling both the C-60 and C-80 spheres. "We're trying to make halves of these molecules and then put those halves together" -- a goal that remains elusive, says the University of California, Los Angeles, researcher. …