Poly-pnictogen bonding: trapping halide ions by a tetradentate antimony(iii) Lewis acid

J Louis Beckmann; Jonas Krieft; Yury V Vishnevskiy; Beate Neumann; Hans-Georg Stammler; Norbert W Mitzel

doi:10.1039/d3sc04594c

Poly-pnictogen bonding: trapping halide ions by a tetradentate antimony(iii) Lewis acid

Chem Sci. 2023 Nov 10;14(46):13551-13559. doi: 10.1039/d3sc04594c. eCollection 2023 Nov 29.

Authors

J Louis Beckmann¹, Jonas Krieft¹, Yury V Vishnevskiy¹, Beate Neumann¹, Hans-Georg Stammler¹, Norbert W Mitzel¹

Affiliation

¹ Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany mitzel@uni-bielefeld.de.

Abstract

A highly halide affine, tetradentate pnictogen-bonding host-system based on the syn-photodimer of 1,8-diethynylanthracene was synthesized by a selective tin-antimony exchange reaction. The host carries four C[triple bond, length as m-dash]C-Sb(C₂F₅)₂ units and has been investigated regarding its ability to act as a Lewis acidic host component for the cooperative trapping of halide ions (F^-, Cl^-, Br^-, I^-). The chelating effect makes this host-system superior to its bidentate derivative in competition experiments. It represents a charge-reversed crown-4 and has the ability to dissolve otherwise poorly soluble salts like tetra-methyl-ammonium chloride. Its NMR-spectroscopic properties make it a potential probe for halide ions in solution. Insights into the structural properties of the halide adducts by X-ray diffraction and computational methods (DFT, QTAIM, IQA) reveal a complex interplay of attractive pnictogen bonding interactions and Coulomb repulsion.