Strategies that have been used to overcome the challenges of Ln heterobimetallic synthesis can be grouped into two broad categories: thermodynamic and kinetic control. Thermodynamic control involves ligands which use variation in ionic radius across the period to statistically assemble selective heterometallic complexes. Ln with large differences in ionic radius therefore selectively coordinate at different ligand sites. Early studies using this approach achieved high selectivity, and complete selectivity has been achieved in paddlewheel-like multimetallic systems (Figure ). Kinetic control uses ligands which form kinetically inert complexes under reaction conditions, with high binding constants (typically K > 10 ) so that redistribution is inaccessible. Individual kinetically inert complexes are then linked to construct multimetallic architectures (Figure 1b). This approach was first used to assemble stacked porphyrin sandwich complexes, but has also been used for the synthesis of cyclic amine carboxylate heteromultimetallic complexes. Recently, stepwise synthesis of peptides with immobilised Ln-containing side groups has been shown to provide flexible access to multimetallic complexes with higher nuclearities, and with the potential for further scalability. While successful for the preparation of a range of heterometallic complexes, these strategies inherently limit Ln combinations and/or the bridging and ancillary ligands they incorporate. Targeting specific properties in bridging ligands can be particularly challenging. As a result, despite the importance of non-innocent ligands in f-block reactivity, interest in radical ligands for molecular magnetism, and applications of multi-spin systems in spintronics, Ln heteromultimetallic complexes containing redox-active bridging ligands have never previously been reported. To address this, we set out to develop a flexible strategy for heterometallic complex synthesis that would allow the introduction of new types of bridging ligand between non-selective metal ions such as lanthanides. In this study, we use a redox-active radical bridge as a template. Our strategy combines the principles of the two approaches previously used for Ln heterobimetallics: individually kinetically inert Ln precursor complexes are designed using ancillary ligands to exhibit thermodynamic selectivity to different binding sites of a bridging ligand.