A computational characterization of CO@C₆₀

The carbon monoxide encapsulation into C₆₀ is evaluated using the DFT and MP2 calculations. The CO encapsulation is attractive, yielding an energy gain of more than 12 kcal/mol. This substantial encapsulation energy should produce at the conditions used in the high-temperature and high-pressure synthesis (originally used for encapsulation of rare gases in fullerenes) an equilibrium CO@C₆₀ fraction of about 3.5% compared to the empty C₆₀. The computed IR and NMR spectra agree with the available observations for CO encapsulated into open-cage C₆₀ derivatives.