# Liquid Metal-Organic Frameworks

## TL;DR

This paper introduces a novel liquid metal-organic framework (MOF) obtained by melting a zeolitic imidazolate framework, retaining key structural features, and studies its properties through experimental and computational methods.

## Contribution

It is the first to demonstrate a MOF liquid with preserved structure and porosity, expanding the understanding of disordered MOF states beyond crystalline forms.

## Key findings

- Successful melting of ZIF while retaining chemical and structural features
- Structural characterization of MOF liquid at the molecular scale
- Insights into the thermodynamics of the solid-liquid transition in MOFs

## Abstract

Metal--organic frameworks (MOFs) are a family of chemically diverse materials, with applications in a wide range of fields covering engineering, physics, chemistry, biology and medicine. Research so far has focused almost entirely on crystalline structures, yet a clear trend has emerged shifting the emphasis onto disordered states of MOFs, including "defective by design" crystals, as well as amorphous phases such as glasses and gels. Here we introduce a MOF liquid, a strongly associated liquid obtained by melting a zeolitic imidazolate framework (ZIF), with retention of chemical configuration, coordinative bonding modes, and porosity of the parent crystalline framework. We combine in-situ variable temperature X-ray, ex-situ neutron pair distribution function experiments, and first principles molecular dynamics simulations to study the melting phenomenon and the nature of the liquid obtained, focusing on structural characterization at the molecular scale, dynamics of the species, and thermodynamics of the solid--liquid transition.