Synthesis and XRD study of an C₂-linked bis(quaternary ammonium) pentaborate: [Me₃NCH₂CH₂NMe₃][B₅O₆(OH)₄]₂

Abstract

The synthesis and characterization of a C₂ (ethane) linked bis(trimethylammonium) pentaborate salt, [Me₃NCH₂CH₂NMe₃][B₅O₆(OH)₄]₂ (1), is reported . Compound 1 has been characterized by ¹H, ¹¹B, and ¹³C NMR Spectroscopy, IR spectroscopy, thermal (TGA/DSC) analysis, and single-crystal X-ray diffraction. There are two independent crystallographic pentaborate(1-) anions in the solid-state structure and these link by H-bonds at β-sites into a centrosymmetric tetrameric chain. These chains are crossed-linked by R₂²(8) H-bond motifs to α-sites of neighboring pentaborate tetrameric units. The [Me₃NCH₂CH₂NMe₃]²⁺ cations are located between these tetrameric pentaborate(1-) units.

Graphical Abstract

Keywords:

• Oxidoborate
• pentaborate(1-)
• polyborate
• 1,2-bis(trimethylammonium)ethane
• X-ray structure

Acknowledgements

We thank the EPSRC for the NCS X-ray crystallographic service (Southampton).