Study of proton transfer in aniline–HCl–catalyst complexes

Abstract

The aniline–HCl–A complexes are studied using DFT (B3LYP) method and 6-31+G (d,p) basis set. A is a catalyst molecule such as H 2SO 4, H 2SO 3, HCOOH, HNO 3, HF, CH 3OH, H 2O, H 2O 2, HNO 2(b), HNO 2(a), NH 3, HCOH, HCN, HCl, H 2S and PH 3. We found that the proton transfer take place in 12 structures in which A = H 2SO 4, H 2SO 3, HCOOH, HF, HNO 2(a), HNO 3, H 2O 2, H 2O, NH 3, HNO 2(b), HCl, CH 3OH and not occurred in another 4 structures with A = HCOH, HCN, H 2S and PH 3. The interaction energies ( E int) of the complexes are computed and correlation between E int and the extent of proton transfer is investigated. The atoms in molecules theory (AIM) of Bader is also applied to study the intra-cluster hydrogen bonds in the aniline–HCl–A clusters. Additionally, the influence of phenyl ring on the proton transfer reaction is computed with the complexes structures without the phenyl ring (NH 3–HCl–catalyst).