Single-Crystal Structure of a Covalent Organic Framework

The crystal structure of a new covalent
organic framework, termed
COF-320, is determined by single-crystal 3D electron diffraction using
the rotation electron diffraction (RED) method for data collection.
The COF crystals are prepared by an imine condensation of tetra-(4-anilyl)­methane
and 4,4′-biphenyldialdehyde in 1,4-dioxane at 120 °C to
produce a highly porous 9-fold interwoven diamond net. COF-320 exhibits
permanent porosity with a Langmuir surface area of 2400 m2/g and a methane total uptake of 15.0 wt % (176 cm3/cm3) at 25 °C and 80 bar. The successful determination of
the structure of COF-320 directly from single-crystal samples is an
important advance in the development of COF chemistry.