Potassium tetraphenylborate
# Potassium tetraphenylborate

Potassium tetraphenylborate is the salt with the formula $KB(C_6H_5)_4).$ It is a colourless salt that is a rare example of a water-insoluble salt of potassium.

The salt has a low solubility in water of only $1.8×10^{−4}$ g/L. It is, however, soluble in organic solvents. The insolubility of this compound has been used to determine the concentration of potassium ions by precipitation and gravimetric analysis:

    $K^+$ + $NaB(Ph)_4$ → $KB(Ph)_4$ + $Na^+$

The compound adopts a polymeric structure with bonds between the phenyl rings and potassium. As such it is classified as an organopotassium compound.

