Faculty of Chemistry, University of Wrocław, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland.
Int J Mol Sci. 2022 Oct 18;23(20):12439. doi: 10.3390/ijms232012439.
In this work, over 500 structures of tri-ring aromatic Schiff bases with different substitution patterns were investigated to develop a unified description of the substituent effect on the intramolecular hydrogen bridge. Both proximal and distal effects were examined using Density Functional Theory (DFT) in the gas phase and with solvent reaction field (Polarizable Continuum Model (PCM) and water as the solvent). In order to investigate and characterize the non-covalent interactions, a topological analysis was performed using the Quantum Theory of Atoms In Molecules (QTAIM) theory and Non-Covalent Interactions (NCI) index. The obtained results were summarized as the generalized, empirical model of the composite substituent effect, assessed using an additional group of simple ring-based Schiff bases. The composite substituent effect has been divided into separate increments describing the different interactions of the hydrogen bridge and the substituent: the classical substituent effect, involving resonance and induction mediated through the ring, steric increment based on substituent proximity to the bridge elements, and distal increment, derived from substitution on the distal ring.
在这项工作中，研究了超过 500 种具有不同取代模式的三环芳香席夫碱结构，以对分子内氢键的取代基效应建立统一的描述。使用密度泛函理论（DFT）在气相中和溶剂反应场（极化连续模型（PCM）和水作为溶剂）中分别考察了近端和远端效应。为了研究和表征非共价相互作用，使用原子在分子中的量子理论（QTAIM）理论和非共价相互作用（NCI）指数进行了拓扑分析。将所得结果总结为复合取代基效应的广义经验模型，并使用另一组基于简单环的席夫碱进行了评估。复合取代基效应已分为单独的增量，描述了氢键和取代基的不同相互作用：经典取代基效应，涉及通过环介导的共振和诱导，基于取代基与桥接元素的接近程度的立体位阻增量，以及源自远端环取代的远端增量。
