Counter‐Intuitive Gas‐Phase Reactivities of [V 2 ] + and [V 2 O] + towards CO 2 Reduction: Insight from Electronic Structure Calculations

[V 2 O] + remains “invisible” in the thermal gas‐phase reaction of bare [V 2 ] + with CO 2 giving rise to [V 2 O 2 ] + ; this is because the [V 2 O] + intermediate is being consumed more than 230 times faster than it is generated. However, the fleeting existence of [V 2 O] + and its involvement in the [V 2 ] + → [V 2 O 2 ] + chemistry are demonstrated by a cross‐over labeling experiment with a 1:1 mixture of C 16 O 2 /C 18 O 2 , generating the product ions [V 2 16 O 2 ] + , [V 2 16 O 18 O] + , and [V 2 18 O 2 ] + in a 1:2:1 ratio. Density functional theory (DFT) calculations help to understand the remarkable and unexpected reactivity differences of [V 2 ] + versus [V 2 O] + towards CO 2 .