Influence of substituents on CH-π interactions in complexes involving X-acetylene and planar cyclooctatetraene

Nmr properties of the ch-π interactions in the x-c2h┴c8h8 complexes (where ┴ denotes ch-π interaction and x = nh2, oh, h, f, no2, and cn) have been investigated at the m05-2x/6-311++g** level of theory. correlations of geometrical parameters, hammett constants, results of atoms in molecules (aim) analysis, charge transfer (ct) and nmr data, particularly two-bond 13c-1h spin-spin coupling constant 2hjc-h, with binding energies were considered. the binding energies of these complexes were also compared with the x-c6h5┴c8h8 complexes to explore the role of acidic hydrogen of acetylene on binding energies. the results of this study aid us to better realize the nature of the ch-π interactions in complexes which encompass planar cyclooctatetraene as an anti-aromatic molecule.