The Element Tin Flouts Carbon's Chemistry Rules: Heavy Metals Don't Always Behave like Organic Neighbor
Ehrenberg, Rachel, Science News
Just because carbon jumps off a bridge, doesn't mean that tin will too. Scientists have conducted an experiment that attaches a simple hydrocarbon to triple-bonded tin atoms, violating a well-established set of organic chemistry rules. The finding suggests that heavier elements don't behave the same way as carbon, a team reports in the Sept. 25 Science.
In the new work, tin atoms bonded to ethylene, a small molecule consisting of two carbon and four hydrogen atoms. Tin should, in principle, be chemically similar to carbon. But carbon does not undergo this same reaction.
"I believe this is a reaction that could lead to further breakthroughs in fundamental science," says Lawrence Sita of the University of Maryland in College Park, who wrote a commentary on the research in the same issue of Science. "This could be a launching point for a number of experiments."
In the mid-1960s, chemists Robert Woodward and Roald I toffmann showed that certain reactions involving carbon-containing molecules are more likely than others. These reactions proceed in a predictable manner based on the symmetry of orbitals, regions of space occupied by electrons as they whiz around in the atoms involved.
Woodward and Hoffmann's rules revealed order in a bunch of seemingly unrelated reactions. But the rules were based on carbon, and few considered how they applied to other elements. Because tin resides in the same column of the periodic table of chemical elements as carbon, it was thought tin would exhibit similar chemical properties and presumably follow the same rules. …