This thesis focuses on the design, synthesis and analysis of multinuclear mixed-valent dioxolene complexes and Cu(II) nitroxyl complexes. Chapter 1 contains a review of the relevant literature for the field of mixed-valent dioxolene complexes and molecular magnetism in nitroxyl complexes. Chapter 2 reports the synthesis and crystallographic analysis of a series of novel highly porous solvent-supported supramolecular assemblies of triptycene derivatives. Chapter 3 reports the complexation and characterisation of triptycene derivatives and related multi-dioxolene ligands with Pt(II). Chapter 4 reports the synthesis, complexation and characterisation of a rigid tris(dioxolene) CTC derivative with Pt(II). It also describes the attempted synthesis of coordination polymers containing multi-dioxolene ligands. Chapter 5 reports the synthesis and characterisation of a series of Cu(II) complexes containing the biradical ligand bisimpy. Chapter 6 contains a description of all synthetic procedures undertaken during this work.