(Quinoline-2-carboxyl-ato-κO)(quinoline-2-carb-oxy-lic acid-κO)bis-(quinoline-2-carb-oxy-lic acid-κN,O)potassium

The K atom in the title complex, [K(C(10)H(6)NO(2))(C(10)H(7)NO(2))(3)], lies on a twofold rotation axis that relates one N,O-chelating quinoline-2-carb-oxy-lic acid to the other; their N and O atoms are cis to each other in the distorted octa-hedral coordination geometry. The K atom is also coordinated by another monodentate quinoline-2-carb-oxy-lic acid; the acid is disordered with respect to a monodentate quinoline-2-carboxyl-ate anion; the acid and anion are linked by an O-H⋯O hydrogen bond. An O-H⋯N hydrogen bond links adjacent mol-ecules into a linear chain structure along the a axis.