Aliphatic–aromatic stacking interactions in cyclohexane–benzene are stronger than aromatic–aromatic interaction in the benzene dimer

Abstract

Stacking interactions between cyclohexane and benzene were studied in crystal structures from the Cambridge Structural Database and by ab initio calculations. Calculated at the very accurate CCSD(T)/CBS level of theory, the cyclohexane-benzene interaction energy is -3.27 kcal mol, which is significantly stronger than the interaction in the benzene dimer (-2.84 kcal mol) indicating the importance of aliphatic-aromatic interactions.

Dimerization Constants from Acoustic Measurements: Solutions of Benzene, Cyclohexylamine and Aniline in Cyclohexane

“…Non-ideality of this system was also stressed by Bottomley and Coopes based on the vapor pressure method [69]. Recently, Ninkovic et al [70] found from crystal structures and ab initio calculations that the cyclohexane–benzene interaction energy is significantly stronger than that for the benzene dimer, indicating the importance of aliphatic–aromatic interactions. This is probably responsible for the relatively large deviations of the Natta–Baccaredda and Benson–Kiyohara models from experiment results observed over the whole range of concentrations for benzene solutions.…”

Study of Influence of Free Radical Species on Antioxidant Activity of Selected 1,2,4‐Triazole‐3‐thiones

“…All atomic distances of the conventional hydrogen bond are in the range of 1.5 – 3.0 Å, while other interactions show longer distances. It is notable that interactions presented in Tables and S5 include π–alkyl and π–σ hydrophobic interactions with amino acids in various positions . These interactions are defined with high pairwise interaction energy and large atomic distances (≥ 2.5 Å).…”

Computational study of stacked complexes of aliphatic and aromatic species

“…In any case, dispersion contribution increases even more as the distance shortens so the stability of the complexes increases. E TPSS E disp E total C 22 C 14 C 6 C 22 C 14 C 6 C 22 C 14 C 6 C 22 C 14 C 6 π-π σ-π π-σ σ-σ…”

“…[3,4] In fact, the interaction in cyclohexane dimer is quite similar in magnitude to that of benzene dimer, and the mixed cyclohexane-benzene dimer is even more stable. [5,6] In consequence, there seems to be nothing special about π-π stacking, and the term should be considered as a mere geometry descriptor regarding the relative orientation of the monomers constituting a complex.…”