Unraveling the effects of linker substitution on structural, electronic and optical properties of amorphous zeolitic imidazolate frameworks-62 (a-ZIF-62) glasses: a DFT study

Abstract

The relaxed atomic models of amorphous ZIF-62 and ZIF-62 crystal.

The deformation of short-range order leading to rearrangement of topological network structure in zeolitic imidazolate framework glasses

“…For high-temp PRDF, the widening of the first peak is induced by the melting process due to the substitution of the imidazolate. The renewal of the Zn-N bonds upon melting causes structural reconstruction is also confirmed by experiments and simulations ( Madsen et al., 2020 ; Li et al, 2020b ; Zeng, 2021 ). Figure 4 B shows the scheme of the substitution of the imidazolate in ZIF-4 and ZIF-62, where the vertical axis is the distance between Zn-Im and the horizontal axis is time.…”

“…Some studies have also been carried out to reveal differences in the chemical or electronic structure of the amorphous ZIFs through simulations ( Adhikari et al., 2016 ; Baral et al., 2017 ; Cimas et al., 2014 ; Li et al., 2020 ; Xiong et al., 2020a , 2020b ). However, it remains challenging to establish a connection between the physical properties, local topology, and the underlying chemistry of glasses ( Ma and Horike, 2022 ).…”

Mapping short-range order at the nanoscale in metal–organic framework and inorganic glass composites

“…67 We attribute the notable intensity differences around 5 and 6 Å are a result of the relative differences in X-ray and electron scattering, with relatively stronger scattering of the associated Zn–H peaks around 5 Å (ref. 66) and relatively weaker Zn–Zn scattering around 6 Å expected in the electron PDF. Electron and X-ray PDF intensities diverged notably around 5–6 Å for a ZIF-62 crystal (ESI Fig.…”

Atomistic Models of Amorphous Metal–Organic Frameworks

“…This a-ZIF CRN model can easily be expanded to other materials of the ZIF family, by substituting the organic ligands and metal nodes to investigate their influence on derived physical properties. In particular, the change in electronic and optical properties were studied for ZIF-4 and MAF-7 (featuring 1,2,4-triazole ligands) with alternating Li/B metal nodes, 23 ZIF-62 (imidazolate and benzimidazolate ligands) for various ligand ratios, 27 and ZIF-4 with halogenated imidazolates (H atoms substituted with Cl or Br). 28 When available (i.e., only for one ZIF-62 system with a given ratio), the system was validated by comparing the RDF with experimental data, but this could not systematically be performed.…”