Putting Molecules Behind Bars

Gaining control of how molecules arrange themselves in the solid state is important for the design of new materials. Such crystal engineering is discussed in a Perspective by Zimmerman, who comments on results published in the same issue by Russell et al . (p. [575][1]). Often, desired molecular structures collapse because the molecules attempt to pack as closely as possible. Russell et al . have fabricated materials called clathrates in which small molecules are imprisoned within a molecular framework that forms stable parallel stacking sheets. Applications of such host-guest complexes include drug delivery and trapping and storage of toxic materials. [1]: http://www.sciencemag.org/cgi/content/full/276/5312/575