Theoretical study of the P-Ylide reaction in the carbon nanotube

Recent studies have shown that the inner phase of carbon nanotubes (CNTs) can not only change the properties of molecules inside the tube, but also enhance or restrain the S_N2 reactions. Thus, the CNTs can be considered a form of solid solvent. In this paper, we study the 2+2] cycloaddition reaction between CH₂O and PH₃CH₂ in the gas phase, benzene solution and inner phase of CNT using the density functional theory (DFT). The results indicate that the inner phase of CNT has little effect on the 2+2] cycloaddition reaction. This can be explained as that while taking the linear arrangement for S_N2 reaction, the reactants do not possess the axial symmetry for the studied 2+2] cycloaddition reaction. Therefore, although the CNT has large axial polarizability, it can exert little influence on the 2+2] cycloaddition reaction. Our studies will be helpful for further understanding of the inner phase chemistry of CNTs.