Coordination of Fluoro Ligands toward Sodium Ions Makes the Difference: Aqua Sodium Ions Act as Brønsted Acids in Polymerization of Vinyl Ethers and Styrenes

In searching for aqua sodium species acting as Brønsted acids in
catalysis, we explored the phenomenon that sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate dihydrate (NaBArF4·2H2O) evidently
provides one proton source to initiate the polymerization of vinyl
ethers in anhydrous dichloromethane solutions. In addition, NaBArF4
catalyzed efficiently in the polymerization of activated styrenes,
such as p-methoxystyrene.