“…Especially ionic liquids have been in the focus of interest since they provide low viscosities, low melting points, and viscosities in combination with large electrochemical windows and high thermal stability [2,3] . Because of these advantageous properties, TCB ‐ILs have been studied for diverse materials applications ranging from dye‐sensitized solar cells (DSSCs, Grätzel cells), components of membranes to battery electrolytes, [1b,7] which also explains the industrial interest in TCB salts and related cyanidoborate salts [8] and especially ionic liquids, in general [2,3,9] . Tetracyanidoborates have also been used as starting materials for the synthesis of salts of other borate anions, containing for example the [B(CF 3 ) 4 ] − , [B(CO 2 H) 4 ] − , [BH(CN) 3 ] − , or the [BH 2 (CN) 2 ] − anion [6b,10] …”