Опубликована: Янв. 1, 2024

Six polycyclic heterocyclic quinones (PHQs) and one unexpected product (compound 6) are synthesized in this work their structures all approved by 1HNMR, 13CNMR HRMS. Four crystal of the seven products obtained. In work, weak interactions these crystals divided as hydrogen bond, n-π interaction, π-π stacking σ-π interaction halogen bond interaction. Since various often co-occur interactions, "Hydrogen atom substitution" method is used to separate calculate energies mechanisms based on NBO analysis. Although both electrostatic orbital important it seems that plays key role. Whether an electrons donor or acceptor, orientation most determines extent overlap. Both energy level electron population number play role bonds interactions. Among have largest least energies, respectively. addition, negative hyperconjugation effects nitrogen atoms significant calculated PHQs, disappear with disappearance lone pair atom. The (or oxygen) compress length covalent nearby, but usually does not destroy conjugative system nearby. However, steric repulsive effect N-H opposite

Язык: Английский