The metal-organic complex Tris(8-hydroxyquinolato) aluminum (Alq(3)) has been studied by energy and light polarization dependent photoemission. Resonant photoemission was used to identify the molecular orbitals involved in metal chelation. When adsorbed on cobalt and gold surfaces, marked differences in the Alq(3) metal-to-ligand bonds were observed. The results indicate intramolecular aluminum-to-ligand bonding through the oxygen heteroatom when Alq(3) is adsorbed on gold, but through the nitrogen heteroatom when on cobalt. These results indicate that substrate interfacial complex formation plays an important role in the Alq(3) molecular configuration and intramolecular bonding. (c) 2005 Elsevier B.V. All rights reserved.