SELF-ASSEMBLING TREFOIL KNOT

Serendipity, along with the hydrophobic effect and a relatively simple chemical building block, has led to the creation of the world’s first molecular knot that forms in water with stereochemical purity. A team of U.K.-based researchers led by Jeremy Sanders of the University of Cambridge and G. Dan Pantoş of the University of Bath reports the new trefoil knot—the simplest of all knots, with three topological crossings (Science, DOI: 10.1126/science.1225893). Molecular knots and other higher molecular topologies could form the basis of new pharmaceuticals and materials, comments University of Zurich chemist Jay S. Siegel, who was not involved in the work. He says he believes that knot topologies “will lead to new catalytic, bioactive, and nanotech materials rich in function.” When chemists build a molecular knot, they typically have to anchor the molecular strand, Siegel notes in an associated commentary, to keep the “relative orientation of the entwined strands in