Control of spin orbit coupling enables the targeted modulation of coherence, catalytic, and magnetic properties in metal complexes. In this Forum, we describe our approach to exerting synthetic control over spin-orbit coupling by using heavy diamagnetic main-group metals as an external source of spin-orbit coupling. By binding these elements to first-row transition metals, we can probe the manifestation of spin-orbit coupling in their properties, by breaking spin orbit coupling into a two-atom phenomenon. Within this approach, we focus on metal ligand covalency and the importance of covalency in spin orbit coupling transfer. To fully understand these systems, we need to design molecules that support careful decoupling of the influences of ligand field geometry and ligand-derived spin-orbit coupling on the magnetic anisotropy of paramagnetic transition metals. These design criteria, along with the advantages of bimetallic species, are described. We anticipate this perspective will offer a fundamental model for using two-metal systems for engendering spin-orbit coupling.