Anion Recognition Based on a Combination of Double-Dentate Hydrogen Bond and Double-Side Anion−π Noncovalent Interactions

Abstract

Anion recognitions between common anions and a novel pincer-like receptor (N,N'-bis(5-fluorobenzoyloxyethyl)urea, BFUR) were theoretically explored, particularly on geometric features of the BFUR@X (X = F, Cl, Br, I, CO, NO, and SO) systems at a molecular level in this work. Complex structures show that two N-H groups as a claw and two -CF rings on BFUR as a pair of tweezers simultaneously interact with captured anions through cooperative double-dentate hydrogen bond and double-side anion-π interactions. The binding energies and thermodynamic information indicate that the recognitions of the seven anions by BFUR in vacuum are enthalpy-driven and entropy-opposed, which occur spontaneously. Although the binding energy ΔE between F and BFUR is relatively high (289.30 kJ·mol), ΔE, ΔG, and ΔH of the recognition for CO and SO are much larger than the cases of F, Cl, Br, I, and NO, suggesting that BFUR is an ideal selective anion receptor for CO and SO. Additionally, energy decomposition analysis based on localized molecular orbital energy decomposition analysis (LMO-EDA) was performed; electronic properties and behaviors of the present systems were further discussed according to calculations on frontier molecular orbital, UV-vis spectra, total electrostatic potential, and visualized weak interaction regions. The present theoretical exploration of BFUR@X (X = F, Cl, Br, I, CO, NO, and SO) systems is fundamentally crucial to establish an anion recognition structure-property relationship upon combination of different noncovalent interactions, that is, double-dentate hydrogen bond and double-side anion-π interactions.

Noncovalent Bonds through Sigma and Pi-Hole Located on the Same Molecule. Guiding Principles and Comparisons

“…As examples, understanding the forces behind crystal engineering and supramolecular chemistry benefits from a knowledge of σ-hole interactions due to their directionality, strength, and selforganization properties which promote formation of adducts in the solid state [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]. The importance of σ-hole bonding has also been verified in the context of anion recognition processes [53][54][55][56][57][58][59][60][61], materials chemistry [62][63][64][65][66][67][68][69][70][71][72], or biochemistry [73][74][75][76][77][78][79][80][81]. An early work connecti...…”

“…The full range of these sorts of bonds, along with their designations, is summarized in Figure 1. processes [53][54][55][56][57][58][59][60][61], materials chemistry [62][63][64][65][66][67][68][69][70][71][72], or biochemistry [73][74][75][76][77][78][79][80][81]. An early work connecting σ-hole bonds with crucial concepts in chemistry occurred when Grabowski recognized that tetrel bonds can be thought of as a preliminary stage of the very important SN2 reaction [82].…”

Influence of monomer deformation on the competition between two types of σ-holes in tetrel bonds

“…[1][2][3][4][5][6][7][8][9] Their role is also undisputed in biochemical processes [10][11][12] , for example underpinning the connections between receptors and ligands which facilitate protein transport, or enzymatic catalysis. [13][14][15][16][17][18] A thorough understanding of the fundamental nature of noncovalent interactions and their role in controlling molecular complexes is one of the linchpins for future progress of modern chemistry.…”

Synthesis and Characterization of Positively Charged tris‐Imidazolium Calix[6]arene Hosts for Anion Recognition

“…The imidazolium proton's high acidity can promote efficient and strong C‐H .… anion interactions and, in addition, the cationic imidazolium groups, may also induce strong electrostatic interactions with negatively charged anions. Secondary effects, such as anion‐π interactions, could also take place. Overall, this series of complementary interactions makes calixarenes which bear pendant imidazolium groups interesting units for an investigation of their anion binding ability.…”