Theoretical exploration of the mechanism of α-pinene hydrogenation

In this paper, density functional theory (DFT) is used to investigate the hydrogenation mechanism of pinene. The experimental route to study the mechanism of selective hydrogenation of pinene is well defined. Under the DFT theoretical model, the positions before and after the reaction structure changed on the carbon-carbon double bond, and the calculated IR/Raman/UV/NMR/frontline molecular orbitals and transition state are consistent, indicating that the unstable bond of pinene is a C=C double bond and that the main hydrogenation reaction occurs. And the transition state of α-pinene is predicted to be an open-loop state and the transition state of β-pinene is a closed-loop state after the hydrogenation of pinene. The simulation of the transition state shows that the reaction model is based on the known catalytic molecular mechanism of the catalytic element and can elucidate at the atomic-molecular level that the active site of pinene is a double bond.