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 Mocks 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 angstrom 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).