TITLE:
Quantum Mechanical Study on the π-π Stacking Interaction and Change in Conformation of Phenolic Systems with Different Intermolecular Rotations
AUTHORS:
Ibrahim Ali, Shruti Sharma, Bipul Bezbaruah
KEYWORDS:
Phenolic System, π-π Stacking, B3LYP, M062X
JOURNAL NAME:
Computational Chemistry,
Vol.6 No.4,
October
20,
2018
ABSTRACT: Aromatic systems like phenol, diphenol, cyano benzene, chloro benzene, aniline
etc shows effective π-π stacking interactions, long range van der Waals
forces; ion-π interactions etc. and these forces of interactions play an crucial
role in the stability of stacked π-dimeric system. On the other hand, substituents
and conformational change in the stacked dimmers of aromatic system
may also change the stability of different stacked dimers. In this current
study, stacked phenolic dimmers (both phenol and diphenol) have been taken
for investigation of the stacking π-π interaction. But, the stacking interactions
are also greatly affected by the conformational change with internal rotation
(i.e. dihedral angle, φ) between the stacked dimers. It is generally accepted
that larger basis sets are required for the highly accurate calculation of interaction
energies for any stacked aromatic models. But, it has recently been reported
that M062X/6-311++G(d,p) basis set is effectively better than that of
B3LYP/6-311++G(d,p) for determining the interaction energies for any kind
of long range interaction in aromatic systems. Therefore, all the calculations
were carried out by using M062X/6-311++G(d,p) basis set. However, in most
of the cases the calculated π-π stacking interaction energies show almost same
result for both DFT and ab initio methods.