Poly[methylammonium tris(mu(2)-formato-kappa2O:O')cobalt(II)].

The structure of the title compound, {(CH(6)N)[Co(CHO(2))(3)]}(n), consists of a three-dimensional net of central Co(II) ions connected via formate (methanediolate) bridges. The negative charge is compensated by protonated methylamine cations. The CoO(6) chromophores form slightly distorted octahedra, which are bridged by C atoms of formate groups. The central Co atom lies on an inversion center and most of the other atoms lie on an m plane.