I am searching for some papers which form complex between crown ether and caesium carbonate. But Most papers only use caesium carbonate as a base in the synthesis of crown ether, not ionic compound for chelation. Can't caesium carbonate form complex with crown ether? Does the fact that caesium carbonate is a base have to do with it? More generally, does the anion of ionic compound also affect the formation of complex between crown ether and metal cation?