Theoretical study of - stacking interactions in substituted-coronene||cyclooctatetraene complexes: A system without direct electrostatic effects of substituents

Abstract

Stability of the ;-; stacking interactions in the substituted-coronene||cyclooctatetraene complexes was<br />studied using the computational quantum chemistry methods (where || denotes ;–; stacking<br />interaction, and substituted-coronene is coronene which substituted with four similar X groups; X =<br />OH, SH, H, F, CN, and NO). There are meaningful correlations between changes of geometrical<br />parameters and topological properties of the electron charge densities at ring critical points due to<br />formation of complexes and ;-; stacking binding energies. In these complexes both electronwithdrawing<br />and electron-donating substituents lead to larger binding energies compared to X = H<br />(unsubsitituetted-coronene||cyclooctatetraene complex).This finding was interpreted on the basis of<br />NMR data, especially spin-spin coupling constants between C atoms of cyclooctatetraene and C atoms<br />at central rings of substituted-coronenes. Herein, relationships between the ;–; stacking binding<br />energy (- E) values and, through-space C-C spin-spin coupling constants (JC-C) in the substitutedcoronene||<br />cyclooctatetraene complexes has been investigated in the complexes without direct<br />electrostatic effects of substituents.