An efficient synthesis for tetracyanoborates by sinter processes

A new efficient synthesis for tetracyanoborates in molar scale starting from the readily available reagents K[BF4], LiCl and KCN is presented. The tetracyanoborate, obtained after the sinter process and work up, is in contrast to the products of the reactions known so far a white solid without any impurities. The thermal behaviour of the mixed cyanofluoroborates, K[BFx(CN)(4-x)] (X = 1-3), was investigated to solve the mechanism of the ligand exchange that takes place during the K[B(CN)(4)]-synthesis. Furthermore several metathesis reactions for the synthesis of different tetracyanoborates are described.