The Properties, Synthesis, and Materials Applications of 1,4-Dithiins and Thianthrenes

1,4-Dithiin and its dibenzo-analogue, thianthrene, represent a class of non-aromatic, sulfur-rich heterocycles. Their unique properties, stemming from both their non-planar structures and reversible one- and two-electron oxidations, serve as primary motivators for their use in the development of new materials. The applications of 1,4dithiins and thianthrenes are rich and diverse, having been used for energy storage and harvesting, and the synthesis of phosphorescent compounds and porous polymers, among other uses. This review offers first an overview of the properties of 1,4-dithiin and thianthrene. Next, we describe enabling synthetic methodology to access 1,4-dithiins and thianthrenes with various substitution patterns. Lastly, the utility of 1,4dithiin and thianthrene in the construction and design of new materials is detailed using select literature examples. 1 Introduction 2 Properties of 1,4-Dithiins and Thianthrenes 3 Synthesis of 1,4-Dithiins and Thianthrenes 3.1 Synthesis of 1,4-Dithiins 3.2 Synthesis of Thianthrenes 4 Application of 1,4-Dithiins and Thianthrenes in Materials 4.1 Thianthrene-Containing Polymers 4.2 Thianthrene in Redox-Active Materials 4.3 Thianthrenes and 1,4-Dithiins in Supramolecular Chemistry and Self-Assembly 4.4 Thianthrenes in Phosphorescent Materials 4.5 Thianthrenes with Other Interesting Photophysical Properties 4.6 Thianthrenes in the Synthesis of Non-natural Products 5 Conclusion