CAS 148-24-3 8-Hydroxyquinoline 8-Hydroxy Quinoline Used for the Metal complex dye Halquinol 8-Hydroxyquinoline (CAS 148-24-3), also known as Oxine or 8-Quinolinol, is an organic compound with the formula C9H7NO that appears as a white to light yellow crystalline powder. It is a lipophilic, planar molecule with strong metal-chelating properties, meaning it can form stable complexes with metal ions.