Dipotassium maleate with boric acid

Abstract

In the title compound, poly[(mu(3)-boric acid)-mu(4)-maleato-dipotassium], [K-2(C4H2O4){B(OH)(3)}](n), there are two independent K+ cations, one bonded to seven O atoms ( three from boric acid and four from maleate), and the other eight-coordinate via three boric acid and four maleate O atoms and a weak eta(1)-type coordination to the C = C bond of the maleate central C atoms. Hydrogen bonding links the boric acid ligands and maleate dianions, completing the packing structure.