Synthesis of a Boronic Acid Anhydride Based Ligand and Its Application in Beryllium Coordination

Abstract

The synthesis of a boronic acid anhydride‐based ligand containing one three‐ and one four‐coordinated boron atom is presented. This ligand was successfully employed as a tridentate κ1N,κ2O‐ligand in the coordination of beryllium chloride and both the ligand and the resulting complex have been structurally characterized. While the boron‐element separations are within the typical range of related homo‐nuclear compounds, the corresponding beryllium‐element distances are rather long, suggesting unexpectedly high electron density at the beryllium center. Incorporation of a beryllium atom in a six‐membered ring causes no more distortion than the corresponding boron atom, suggesting that analogous ligand systems could be used in boron and beryllium coordination chemistry. The generated hetero‐tri‐nuclear complex enables the direct comparison of bond lengths and angles at beryllium and boron atoms in similar coordination environments and can act as a monomolecular model for beryllium borates.

Water-stable boroxine structure with dynamic covalent bonds

“…HO-PBA dimer HO-PBA is a useful organic molecule that is widely employed in organic reactions and catalysis 17,23,24 . However, its single-crystal structure, which enables the visualization of intermolecular interactions and provides insights into stereochemistry and reaction selectivity, is currently unavailable.…”

Towards more effective beryllium chelation: an investigation of second-sphere hydrogen bonding

“…1,11,12 Beryllium is the least electropositive alkali metal and tends to favour a tetrahedral coordination geometry, ligated by medium-to-hard donors such as oxygen and nitrogen. [13][14][15][16] Despite a renewed renaissance in beryllium coordination chemistry, 7,[17][18][19][20][21] an as yet unresolved issue remains, that is, the development of ligands which exhibit both high selectivity and have sufficiently high binding constants to be useful in the detection and remediation of beryllium. The handling of beryllium poses serious potential health and safety risks, making its study, even within a laboratory environment, problematic.…”