8-Hydroxyquinoline is a monoprotic bidentate chelating agent The reaction of 8-hydroxyquinoline with aluminium(III) results in Alq3, a common component of organic light-emitting diodes (OLED"s). Variations in the substituents on the quinoline rings affect its luminescent properties. 8-Hydroxyquinoline is employed in precipitating and separating metals, the preparation of fungicides, and as a dye