Stable sulfate and nitrate borane-adduct anions

The addition of potassium or silver salts of nitrate to a solution of B(C6F5)3 in diethyl ether affords salts containing very voluminous B(C6F5)3 mono adduct anions of the type [Ag(Et2O)3]+[NO3·B(C6F5)3]−, and [K(Et2O)2]+[NO3·B(C6F5)3]−. When the double negatively charged sulfate anion was used only for the potassium salt, adduct anion formation was observed upon addition of 18-crown-6. In this case K(18-crown-6)(CH2Cl2)]+[SO4·2 B(C6F5)3]− bearing the diadduct anion was isolated and fully characterized. These salts are thermally stable up to over 200 °C and dissolve in polar organic solvents.