2007/03/28: Porous Crystalline Organic Frameworks.
Designed syntheses lead to covalent 3-D materials with potential uses in gas storage and separation.
[..]The new materials are three-dimensional covalent organic frameworks (COFs)—that is, porous networks constructed entirely of strong covalent bonds between light elements such as carbon, boron, and oxygen. They are stable to temperatures above 450 °C, and their surface areas (as high as 4,210 m2/g) are among the highest known for any materials. Most strikingly, these materials have extremely low densities. In fact, one member of this family, designated COF—108, boasts a density of just 0.17 g/cm3—the lowest-density crystal known. A diamond, by comparison, has a density of 3.5 g/cm3. [...]