Name the world's most offensive odor: Rotting fish? Refinery fumes? Skunk spray? For many organic chemists, top honors go to a family of carbon-nitrogen-based compounds called isonitriles. This chemical group is "the Godzilla of smells ... they make you vomit your guts out instantly," declared Luca Turin, a leading olfaction theorist and protagonist of Chandler Burr's 2003 biography, The Emperor of Scent. Add the fact that a prime ingredient for isonitriles is phosgene gas--a notorious chemical warfare agent from World War I, and it is little surprise that many investigators shun these noxious and unstable substances despite their acknowledged utility in drug discovery, polymer manufacture and elsewhere.
That situation is apt to change soon, however. Two researchers at the University of California, Riverside, have recently synthesized fragrant isonitriles that not only work just as well as their foul-smelling cousins but are safer to formulate. The aromas of the new substances include soy, malt, old wood, cherry and even taffy, report chemist Michael C. Pirrung and his postdoctoral student Subir Ghorai in the Journal of the American Chemical Society. "These compounds are so versatile and easy to make that I think that many people will use them for many purposes," Pirrung predicts.