The Nobel chemistry prize goes for click-together molecules

about putting molecules together and pulling them apart. The details inevitably vary from reaction to reaction. But there are many areas of the subject where it would be useful to have a way of snapping the building blocks of large molecules together regardless of the chemical properties of those smaller units. And for the past two decades there has indeed been such a way. It is known as click chemistry, and its inventors are this year’s l chemistry laureates.Two of the three winners, Morten Meldal of the University of Copenhagen and Barry Sharpless of Scripps Research, in La Jolla, California (already a laureate for work on catalysts), invented the underlying trick. The third, Carolyn Bertozzi of Stanford University, adapted it for use in biological systems. In both cases, though, it uses a pair of chemical groups—azides (in which three nitrogen atoms are linked together in a row) and alkynes (in which two carbon atoms are connected by a triple bond)—that will, in the right circumstances, react to form a structure called a triazole (a five-membered ring of two carbons and three nitrogens), while remaining attached to their original molecules as well. In essence, the azide and the alkyne are like the two halves of a snap-together buckle.