Interplay between π···π stacking and cation···π interaction: a theoretical NMR study

Interplay between π···π stacking and cation···π interaction in cation···benzene···benzene complex is theoretically investigated using NMR viewpoint. The NMR calculations are performed at B3LYP/6-311++G(d,p) and PBE0/6-311++G(d,p) levels of theory. Here, the role of purely geometric and the direct electronic effects on the NMR data is studied. The results indicate that the electronic effects are dominant in determining NMR data. Also, the contribution of cation···π interaction to electronic effects is greater than that of π···π stacking. Moreover, meaningful relationships are also found between synergistic effects and NMR data. In addition to geometrical parameters and binding energies, it is observed that the topological properties of electron charge density can be useful to predict NMR data.