Boro-oxalates, bis(oxalato)borates, or oxalatoborates are chemical compounds where an oxalate group is bound to a borate group via oxygen, forming a condensed anion. The oxalatoborates are heterocyclic compounds with a ring containing -O-B-O-C-C-. Bis(oxalato)borates are spiro compounds with two rings joined at the boron atom.
Oxalatoborates are used for research in lithium-ion battery electrolytes and for supercapacitors.
The borate oxalates are chemical compounds containing separate borate and oxalate anions. Compared to oxalatoborates, these are of little importance.
Oxalatoborates have been produced by heating boric acid, oxalic acid and a metal oxalate, a metal carbonate or an amine in boiling benzene with continuous removal of water via azeotropic distillation.
When heated, oxalatoborates decompose at around 320 ðC to yield a metaborate, carbon monoxide, and carbon dioxide.