(5-Amino-isophthalato-κN)triaqua-(1,10-phenanthroline-κN,N')cobalt(II) trihydrate.

The Co(II) atom in the title compound, [Co(C(8)H(5)NO(4))(C(12)H(8)N(2))(H(2)O)(3)]·3H(2)O, is six-coordinated in a CoN(3)O(3) octa-hedral geometry; the water-coordinated Co(II) atom is chelated by the N-heterocycle. An inter-molecular N-H⋯O hydrogen bond occurs. The carboxyl-ate entity coordinates through the amino group. The carboxyl-ate donor unit, coordinated and uncoordinated water mol-ecules inter-act through O-H⋯O and N-H⋯O hydrogen bonds, generating a tightly-held three-dimensional cage-like network.