Novel (glycerol)borate-based ionic liquids: an experimental and theoretical study

A series of newly designed (glycerol)borate based ionic liquids were synthesized and characterized. The synthesis of these ionic liquids involves, first, the preparation of the bis(glycerol)boric acid(s) followed by neutralization with the appropriate base, [cat]OH. Ionic liquids bearing inorganic (Li+, Na+, K+) or organic cations have been prepared and characterized. The ability of the bis(glycerol)borate anions to undergo dissociation reaction in the presence of water, depending on cation nature, was investigated by NMR. Theoretical calculations were also performed to evaluate the relative stability of the possible bis(glycerol)borate isomers as nude ions or as ion pairs with Li+, Na+, and H+. Important information about the structural features of H[Gly2B] useful to rationalize the chemical behavior have been obtained.