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Updated: Apr 27, 2026

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
A B3LYP and MP2(full) theoretical investigation into cooperativity effects, aromaticity and thermodynamic properties
Guang-ming Zhao1, Yu-cun Liu, Wen-jing Shi
1College of Chemical Engineering and Environment, North University of China, Taiyuan, 030051, China.
Abstract:
The cooperativity effects between H-bonding and Na(+)⋯π or Na(+)⋯σ interactions in Na(+)⋯benzonitrile⋯H2O complexes were investigated using the B3LYP and MP2(full) methods with 6-311++G(2d,p) and aug-cc-pVTZ basis sets. The thermodynamic cooperativity and the influence of this cooperativity on aromaticity was evaluated by nucleus-independent chemical shifts (NICS). The results showed that the influence of the Na(+)⋯σ or Na(+)⋯π interaction on the hydrogen bond is more pronounced than that of the latter on the former. The cooperativity effect appeared in the Na(+)⋯σ interaction complex while the anti-cooperativity effect tended to be in the Na(+)⋯π system. The change in enthalpy is the major factor driving cooperativity. Thermodynamic cooperativity is not in accordance with the cooperativity effect evaluated by the change of interaction energy. The ring aromaticity of is weakened while the bond dissociation energy (BDE) of the C-CN bond increases upon ternary complex formation. The cooperativity effect (E coop) correlates with R c (NICS(1)ternary/NICS(1)binary) and ΔΔδ (Δδ ternary - Δδ binary) involving the ring and C ≡ N bond, as well as R BDE(C-CN) [BDE(C-CN)ternary/BDE(C-CN)binary], respectively. AIM (atoms in molecules) analysis confirms the existence of cooperativity.
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