Organic chemistry

Molecules that vanish in a flash are pinned down

‘Superacid’ baths allow scientists to isolate five elusive chemical intermediates.

Scientists have captured ephemeral organic compounds that appear and disappear in the blink of an eye during common chemical reactions.

Such molecules had previously been made in solution, but no one had ever isolated them as solids. Michael Gerken and his colleagues at the University of Lethbridge in Canada snared the fleeting compounds by running the parent reactions in baths of highly corrosive acid. The reactions created products including solid deposits of a compound that pairs acetone — a widely used industrial solvent — with an extra proton. Four other species of ‘protonated’ organic molecule were also isolated in solid form.

Using spectroscopy and X-ray crystallography, the team worked out the 3D shape of the molecules, which are intermediate products in reactions used to create complex organic molecules, such as pharmaceuticals. The protonated molecules may prove useful in synthetic chemistry, the researchers say.