Atomic structure of the continuous random network of amorphous C[(C6H4)2]2 PAF-1 (vol 3, 100899, 2022)

In the search for stable materials with high porosity, attention has moved toward atomic networks that utilize molecular linkages. PAF-1, with linkages of biphenyl moieties, forms an amorphous network with phenomenal porosity and stability. Until now there still has been no clear picture of its atomic structure. We report here on a study using both neutron scattering and molecular dynamics simulation methods. We demonstrate that PAF-1 forms a continuous random network, in which tetrahedral carbon sites are connected by the biphenyl linkers. The molecular dynamics simulations show local structure with avoidance of close contacts between hydrogen atoms. We observe a distinct peak in the scattering at Q = 0.45 Å−1, corresponding to the first sharp diffraction peak in amorphous silica. This suggests there is structural analogy between the amorphous tetrahedral networks of PAF-1 and silica. © 2022 The Authors