The atom, the molecule, and the covalent organic framework

• Published in: Science (American Association for the Advancement of Science) Vol. 355; no. 6328; p. 923
• Main Authors: Diercks, Christian S., Yaghi, Omar M.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 03.03.2017; The American Association for the Advancement of Science
• Subjects: Assembly; Bonding strength; Boron; Carbon; Carrier mobility; Catalysis; Chemical bonds; Chemical interactions; Chemical reactions; Chemical synthesis; Chemistry; Chemists; Covalence; Covalent bonds; Crystal structure; Crystallinity; Current carriers; Design; Energy storage; Entanglement; Enzymes; Flexibility; Gas separation; Interfaces; Light elements; Molecular chains; Nitrogen; Organic chemistry; Organic solids; Porosity; REVIEW SUMMARY; Silicon; Substrates; Synthesis (chemistry); Unions
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.aal1585

Covalent molecular frameworks are crystalline microporous materials assembled from organic molecules through strong covalent bonds in a process termed reticular synthesis. Diercks and Yaghi review developments in this area, noting the parallels between framework assembly and the covalent assembly of atoms into molecules, as described just over a century ago by Lewis. Emerging challenges include functionalization of existing frameworks and the creation of flexible materials through the design of woven structures. Science , this issue p. eaal1585 Just over a century ago, Lewis published his seminal work on what became known as the covalent bond, which has since occupied a central role in the theory of making organic molecules. With the advent of covalent organic frameworks (COFs), the chemistry of the covalent bond was extended to two- and three-dimensional frameworks. Here, organic molecules are linked by covalent bonds to yield crystalline, porous COFs from light elements (boron, carbon, nitrogen, oxygen, and silicon) that are characterized by high architectural and chemical robustness. This discovery paved the way for carrying out chemistry on frameworks without losing their porosity or crystallinity, and in turn achieving designed properties in materials. The recent union of the covalent and the mechanical bond in the COF provides the opportunity for making woven structures that incorporate flexibility and dynamics into frameworks.