In one of many assassination attempts on Grigori Rasputin, the early 20th century Russian mystic and political adviser to the House of Romanov, sweet pastries were laced with cyanide, which he nevertheless survived eating. One theory about this outcome speculates that carbonyl groups in the sugar molecules created an immediate antidote by reacting with the poison cyanide to form cyanohydrins.
A similar mechanism may account for how plants and animals stand up to cyanide, which is generated in various biological processes. The cyanoformate anion, [NCCOO]-, formed from cyanide (CN) and carbon dioxide (CO2), has been implicated in the inactivation of this poison. But the interaction of these constituents remained elusive, and the anion itself never previously isolated. “It had been detected in mass spectrometry experiments before,” says Jason Clyburne, a chemist at Saint Mary’s University in Halifax. Previously, researchers suspected that [NCCOO]- was formed during the production of ethylene by ripening fruits, but only simpler molecules could be found. “Experimenters could not connect what was going on in the enzyme and the results of their experiments,” Clyburne says.
Clyburne and a Finnish colleague, Heikki Tuononen, looked more closely at this interaction and decided it should be possible to prepare [NCCOO]-. They subsequently isolated this species as its tetraphenylphosphonium salt and characterized it using crystallography, spectroscopy and computational chemistry, publishing their observations in Science this spring. The article was accompanied by a separate item pointing to the significance of such a fundamental discovery. “In the ever-expanding universe of compounds prepared to date,” the article reads, “it is remarkable that a two-carbon ion with an apparently simple electronic structure could have eluded structural characterization until now.”
Clyburne agrees, adding that this result strengthens the justification for continuing to support pure research endeavours, which can turn up surprises even in areas that were long since thought to be fully documented. In this way, even more interesting applications could emerge than might be found from an enterprise dedicated exclusively to applied research. “Whenever people think about studying reactions in solvents, basically what they’re observing is chemistry in a medium that’s being affected by the bulk dielectric,” says Clyburne. “It makes me want to look at the chemistry of charged species in low dielectric environments, to see if other unusual chemistry can go on. Nature clearly has taken advantage of this, so why can’t we?”