Cerium(III) methanesulfonate
# Cerium(III) methanesulfonate

Cerium(III) methanesulfonate is a white salt, usually found as the dihydrate with the formula $Ce(CH_3SO_3)_3·2H_2O$ that precipitates from the neutralisation of cerium(III) carbonate with methanesulfonic acid, as first reported by L.B. Zinner in 1979. The crystals have a monoclinic polymeric structure were each methanesulfonate ion forms bonds with two cerium atoms, which present a coordination number of 8. The anhydrous salt is formed by water loss at 120 °C. Similar methanesulfonates can be prepared with other lanthanides. Cerium(III) methanesulfonate in solution is used as a precursor of electrogenerated cerium(IV), which is a strong oxidant and whose salts can be used in organic synthesis. The same principle of Ce(IV) electrogeneration is the fundamental reaction in the positive half-cell of the zinc–cerium battery.

