High‐Pressure Synthesis and Crystal Structure of the Inoborate Ni[B₂O₂(OH)₄]

The novel inoborate Ni[B 2 O 2 (OH) 4 ] was synthesized under high‐pressure/high‐temperature conditions of 9 GPa and 800 °C. Its structure was determined via single‐crystal X‐ray diffraction analysis. The single‐grain IR‐spectrum of Ni[B 2 O 2 (OH) 4 ] supports the existence of O−H bonds. The structural similarities and differences with the mineral vimsite, possessing the sum formula Ca[B 2 O 2 (OH) 4 ], as well as with the phylloborate HP−Ni(B 2 O 4 ) is discussed. The title compound can be described as the structural hydrolysis product of the latter.