The presented preliminary results serve as proof-of-concept for a reusable and reversible chemisorption system for CO based on the use of zero-valent transition-metal complexes at room temperature driven only by pressure-swing manipulation. We believe that the strategy shown in this work, i.e., (i) the construction of a ligand system that functions even in the solid-state for the reversible CO substitution using flexible multifunctional ligands and (ii) the use of an ionic liquid as the reaction medium, will pave the way for the design of an unprecedented molecular-based chemisorption system that can effectively purify (or remove) CO in a low-energy-consuming and sustainable manner.