Structural investigations of amorphous metal-organic frameworks formed via different routes.

The structures of chemically identical amorphous zeolitic amorphous frameworks (ZIFs), which were prepared from crystalline ZIF-4 via three different routes, are compared by refining atomistic models against their neutron and X-ray total scattering data. The diffraction data are very similar at all but the lowest values of momentum transfer and this is reflected in the ability of models with the same continuous random network topology to fit the data from each of the three amorphous ZIFs. Despite this there are differences in the detail; the relative positions of the lowest-Q peak in the Zn-Zn partial structure factors are consistent with differences in the densities of the different amorphous samples, and peaks in the ZIF-4 glass total scattering structure factors are in general broader, suggesting shorter-ranged correlations.