Rationally fabricating 3D porphyrinic covalent organic frameworks with scu topology as highly efficient photocatalysts

The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.

A new crystalline porous three-dimensional covalent organic framework, termed COF-300, has been synthesized and structurally characterized. Tetrahedral tetra-(4-anilyl)-methane and linear terephthaldehyde building blocks were condensed to form imine linkages in a material whose X-ray crystal structure shows five independent diamond frameworks. Despite the interpenetration, the structure has pores of 7.2 A diameter. Thus, COF-300 shows thermal stability up to 490 degrees C and permanent porosity with a surface area of 1360 m(2) g(-1).