1. Anion-binding properties of π-electron deficient cavity in tetraoxacalix[2]arene[2]triazine by a computational study.
- Author
-
Li, Fengcai, Zhang, Guanglong, Xia, Shuwei, and Yu, Liangmin
- Subjects
- *
CHEMICAL shift (Nuclear magnetic resonance) , *HYDROGEN bonding interactions , *HYDROGEN bonding , *MAGNETIC shielding , *REDSHIFT , *CHARGE exchange - Abstract
Host-guest inclusion complex formation of tetraoxacalix[2]arene[2]triazine (1) with anions X(CH 3 COO−, ClO 4 −, BrO 4 −, IO 4 −, SO 4 2−, SO 3 2−, CO 3 2−, SiO 3 2−) was studied by DFT calculations at M062X/6-311+G** level, together with their equilibrium geometries, binding energies and electronic structures. MESP, NCI-RDG and AIM topography analysis were performed to explore underlying interactions. The inclusion complexes in 1:1 ratio were stabilized through a cooperative effect of non-covalent interactions, including anion-π, σ-interactions, hydrogen bonds and van der Waals interactions. The recognition process of anions within 1 was spontaneous both thermodynamically and dynamically. The structure of molecule 1 changed slightly after encapsulation, reflected in IR and NMR spectra. After complexation, the red shifts of C H stretching and triazine rings bending in IR were attributed by hydrogen bonds and anion-π interactions. Anions encased in the host cavity exhibited magnetic shielding; those bifurcate hydrogen bonds could cause chemical shifts signals in 1H NMR spectra. • Tetraoxa[2]arene[2]triazine can selectively recognize anions. • The anion-π interactions and hydrogen bonds maintain the stability of the system. • The recognition process accompanied with electron transfer and redistribution. • The solvents weaken the binding interaction significantly. • The shifts of IR and NMR spectra are obvious makers of the combination. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF