Structure of Metal–Organic Framework Glasses by Ab Initio Molecular Dynamics

While metal–organic frameworks have been mostly studied in their crystalline form, recent advances have been made on their amorphous phases, both in fundamental understanding and in relation to possible applications. In particular, the zeolitic imidazolate (ZIF) glasses, that can be obtained from quenching liquid ZIFs, have shown promise. However, the details of their microscopic structure are very hard to probe experimentally. Here we use ab initio molecular dynamics simulations to investigate the nature of the ZIF glasses obtained from quenching molten ZIFs in silico. Through computational modeling of the melt–quench process on three different ZIF crystals, we aim to understand the effect of topology and chemistry upon the structure of the glass, compared to crystalline precursor and high temperature liquid. It is the first direct computational description of MOF glasses at the quantum chemical level.