Molecular CO Storage: State of a Single-Molecule Gas.

CO evolution is one of the urgent global issues; meanwhile, understanding of sorptive/dynamic behavior is crucial to create next-generation encapsulant materials with stable sorbent processes. Herein, we showcase molecular CO storage constructed by a [60]fullerenol nanopocket. The CO density reaches 2.401 g/cm within the nanopore, showing strong intramolecular interactions, which induce nanoconfinement effects such as forbidden translation, restricted rotation, and perturbed vibration of CO. We also disclosed an equation of state for a molecular CO gas, revealing a very low pressure of 3.14 rPa (1 rPa = 10 Pa) generated by the rotation/vibration at 300 K. Curiously enough, the CO capture enabled to modulate an external property of the encapulant material itself, i.e., association of the [60]fullerenol via intercage hydrogen-bonding.