This work is concerned primarily with the structural aspects of the heterocyclic dithiadiazolyl and dithiadiazolylium rings. Chapter one reviews both the 7π dithiadiazolyl and the 6π dithiadiazolylium ring systems. The synthetic routes to these ring systems are outlined, as well as the reactions that they are known to participate in. Chapter two outlines the general methods used to synthesise and analyse the compounds prepared and examined in this thesis. Chapter three investigates the crystal structures of various salts containing the dithiadiazolylium ring system. All of these salts possess halide anions, and the relationship between the size of the halogen and its position in relation to the heterocyclic ring is examined. In chapter four the new metallo-dithiadiazolylium species, Hg[CNSNS](_2)[AsF(_6)](-2), is examined as a potential transfer reagent for the dithiadiazolylium ring. The previously unknown halogen-substituted compounds, [X.CNSNS] [AsF(_6)] (X = Br, Cl), have been prepared from this metallo-dithiadiazolylium system. Chapter five outlines the crystal structures of four novel compounds formed by metal-insertion into the S-S bond of the dithiadiazolyl ring. The sixth chapter indicates possible ideas based on the work outlined in this thesis.