Investigation of the Substituent Effects on π-Type Pnicogen Bond Interaction

摘要

Intermolecular interactions between PH2Cl and Ar-R (R =H,OH,NH2,CH3,Br,Cl,F,CN,NO2) were calculated by using MP2/aug-cc-pVDZ quantum chemical method.It has been shown from our calculations that the aromatic tings with electron-withdrawing groups represent much weaker binding affinities than those with electron-donating groups.The charge-transfer interaction between PH2Cl and Ar-R plays an important role in the formation of pnicogen bond complexes,as revealed by NBO analysis.Nevertheless,AIM analysis shows that the nature of the interactions between PH2Cl and Ar-R is electrostatic,and the interaction energies of the complexes are correlated positively with the electron densities in the bond critical points (BCPs).RDG/ELF graphical analyses were performed to visualize the positions and strengths of the pnicogen bonding,as well as the spatial change of the electron localization upon the formation of complexes.The π-type halogen bond was also calculated,and it has been revealed that the π-type pnicogen bond systems are more stable than the halogen bond ones.