Poly[tetra-μ2-L-lactato-indium(III)sodium(I)].

The asymmetric unit of the title compound, [InNa(C(3)H(5)O(3))(4)](n), consists of one In(III) ion, one Na(I) ion and four crystallographically independent L-lactate monoanions. The coordination of the In(III) ion is composed of five carboxylate O and two hydroxy O atoms in a distorted pentagonal-bipyramidal coordination geometry. The Na(I) ion is six-coordinated by four carboxylate O atoms and two hydroxy O atoms from four L-lactate ligands in a distorted octahedral geometry. Each In(III) ion is coordinated by four surrounding L-lactate ligands to form an [In(L-lactate)(4)](-) unit, which is further linked by Na(I) ions through Na-O bonds to give a two-dimensional layered structure. Hydrogen bonds between the hydroxy groups and carboxylate O atoms are observed between neighbouring layers.