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The design and synthesis of crystalline extended organic structures in which the building blocks are linked by strong covalent bonds are core concepts of covalent organic frameworks (COFs). COFs are porous, and crystalline, and made entirely from light elements (H, B, C, N, and O) that are known to form strong covalent bonds in well-established and useful materials such as diamond, graphite, and boron nitride. The successful realization of COF materials through molecular building blocks would provide covalent frameworks that could be functionalized into lightweight materials optimized for gas storage, photonic and catalytic applications.〔Côté, A. P.; Benin, A. I.; Ockwig, N. W.; O'Keeffe, M.; Matzger, A. J.; Yaghi, O. M.; Porous, Crystalline, Covalent Organic Frameworks. ''Science''. 2005, ''310'', pp 1166-1170. 〕 ==Structure== Porous crystalline solids consists of secondary building units (SBUs) which assemble to form a periodic and porous framework. An almost infinite numbers of frameworks can be formed through various SBU combinations leading to unique material properties for applications in separations, storage, and heterogeneous catalysis.〔Kitagawa, S.; Kitaura, R.; Noro, S.; Functional Porous Coordination Polymers. ''Angew. Chem. Int. Ed.'' 2004, ''43'', pp 2334-2375. 〕 Porous crystalline solids can be used to describe materials such as Zeolite, Metal-organic frameworks (MOFs), and Covalent Organic Frameworks (COFs). Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. MOFs are a class of porous polymeric material, consisting of metal ions linked together by organic bridging ligands and are a new development on the interface between molecular coordination chemistry and materials science.〔James, S. L.; Metal-organic frameworks. ''Chem. Soc. Rev.'' 2003, ''32'', pp 276-288. 〕 COFs are another class of porous polymeric materials, consisting of porous, crystalline, covalent bonds that usually have rigid structures, exceptional thermal stabilities (to temperatures up to 600°C), and low densities. They exhibit permanent porosity with specific surface areas surpassing those of well-known zeolites and porous silicates.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「covalent organic framework」の詳細全文を読む スポンサード リンク
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