# Oppositely-charged coordination cages form a type I porous ionic liquid with two pore sizes

## TL;DR

A new porous ionic liquid is created by combining two oppositely-charged coordination cages, offering improved performance for chemical separations and storage.

## Contribution

A novel porous ionic liquid is formed using two oppositely-charged coordination cages with dual pore sizes.

## Key findings

- The ionic liquid has higher porosity than previously reported systems due to its hollow cage components.
- The dual pore sizes allow for guest-binding selectivity, enhancing its potential for chemical separations and storage.
- The material's liquid nature enables a range of applications in porous materials.

## Abstract

Here we introduce a new type of porous liquid that combines two coordination cages in a single salt. This material is prepared through the ion metathesis of two oppositely-charged cages: one charged +20, and the other with a −16 charge. This ionic liquid has higher porosity than previously reported systems, because both of its components are hollow cages. The enhanced porosity holds promise for improving performance in chemical separations or storage, reflecting the guest-binding selectivity of the two cages, and the applications accessible due to its liquid nature.

Oppositely charged metal–organic cages form a neat type-I ionic liquid with dual intrinsic cavities.