On-surface metalation provides a tool to vary magnetic and electronic properties of metal-organic complexes and produces clean samples of the desired product. We used this technique to metalate 5,5′-dibromosalophene with the 3d transition metals Co, Fe, and Cr on Co-intercalated graphene grown on Ir(111). The metalation process was investigated by X-ray photoelectron spectroscopy (XPS). The electronic structure of the obtained salophene complexes was investigated using a combination of scanning tunneling microscopy and spectroscopy with density functional theory calculations. XPS data show that deposition of the transition metals at 398 K causes the metal atoms to interact with the molecules, while higher temperatures are needed to complete the reaction. Furthermore, we are able to distinguish the three different metal-organic complexes by their electronic structure.