A magnesium(II) complex of 1,10-phenanthroline-2,9-dicarboxylate

The title compound, tri­aqua(1,10-phenanthroline-2,9-di­car­box­yl­ato)­magnesium(II) dihydrate, [Mg(PDA)(H2O)3]·2H2O, (H2PDA is 1,10-phenanthroline-2,9-di­carboxyl­ic acid, C14H8N2O4) has twofold crystallographic symmetry. The Mg atom is in a distorted pentagonal bipyramidal coordination environment with two N atoms and two O atoms from PDA and one O atom from a water mol­ecule forming the pentagonal plane, and two O atoms from two water mol­ecules occupying axial positions. The crystal structure comprises an infinite two-dimensional network of hydrogen-bonded mol­ecules.