Cation-Activated Halogen Bonding: Experimental and Theoretical Study of The Enhancement of σ-Hole Potential Due to The Group 1 Elements Coordination

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发表日期：

2025年8月1日

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Y. V. Safinskaya,
A. V. Kovalenko,
M. V. Il’in

摘要

Abstract

This combined experimental and theoretical study examines cation-mediated σ-hole electrostatic potential enhancement in a triethylene glycol derivative functionalized with 2,4,6-tribromophenol ligand system. DFT calculations reveal significant increase of electrostatic potential at bromine sites (up to 352 kJ/mol for Li⁺ coordination, representing a 4-fold enhancement over the free ligand’s potential of 87 kJ/mol). ¹H NMR shows weak Na⁺ binding (K²⁹⁸ = 1.03^–5 M^–1) in acetonitrile, highlighting strong solvent competition effects. The observed nonlinear activation trend (Li⁺ > K⁺ > Na⁺) contrasts with complete absence of the potential enhancement for H⁺, Rb⁺ and Cs⁺ complexes due to geometric constraints.