Disclosed are 2-quinoxalinol salen compounds and in particular 2-quinoxalinol salen Schiff-base ligands. The disclosed 2-quinoxalinol salen compounds may be utilized as ligands for forming complexes with cations, and further, the formed complexes may be utilized as catalysts for oxidation reactions. The disclosed 2-quinoxalinol salen compounds also may be conjugated to solid supports and utilized in methods for selective solid-phase extraction or detection of cations.