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

Abstract

Abstract1,4-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 1,4-dithiins 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 1,4-dithiin and thianthrene in the construction and design of new materials is detailed using select literature examples.1 Introduction2 Properties of 1,4-Dithiins and Thianthrenes3 Synthesis of 1,4-Dithiins and Thianthrenes3.1 Synthesis of 1,4-Dithiins3.2 Synthesis of Thianthrenes4 Application of 1,4-Dithiins and Thianthrenes in Materials4.1 Thianthrene-Containing Polymers4.2 Thianthrene in Redox-Active Materials4.3 Thianthrenes and 1,4-Dithiins in Supramolecular Chemistry and Self-Assembly4.4 Thianthrenes in Phosphorescent Materials4.5 Thianthrenes with Other Interesting Photophysical Properties4.6 Thianthrenes in the Synthesis of Non-natural Products5 Conclusion

One-step synthesis of polycyclic thianthrenes from unfunctionalized aromatics by thia-APEX reactions

“…160 nm, whose relatively large values were considered to be derived from large dynamic structural relaxations at their excited states. 1,7 j Furthermore, the fluorescence quantum yields of thianthrenes 3ca and 3ea were measured as 24% and 4%, respectively. Notably, the 24% quantum yield of 3ca was even larger than those of pristine phenanthrene and triphenylene ( ca.…”

“…6D). 1,22 Besides, the dangling benzodithiine arm is bent toward the concave face of the corannulene core, which forms a ladle-like shape. The one-dimensional columnar packings of 3ea are aligned in an antiparallel manner to the neighboring molecular columns, counteracting the dipole moments of each column (Fig.…”

“…1A). 1 Neutral thianthrene adopts a bent structure whose C–S–C angle is ca. 128°, whereas it reversibly transforms into a planar structure in the radical cation state.…”

ProBox: A Rigid yet Dynamic Cyclophane Capable of Adaptive and Redox-Switchable Host–Guest Binding

“…1,4-Dithiins are a family of redox-active heterocycles featuring dynamic structures. Their neutral form adopts a nonplanar boat conformation and exhibits clamp-like hinge motions by folding along its S···S axis with low inversion barriers . More interestingly, 1,4-dithiins can undergo reversible conformation change from the neutral bent structure to its flat radical species via redox regulation.…”

“…Their neutral form adopts a nonplanar boat conformation and exhibits clamp-like hinge motions by folding along its S•••S axis with low inversion barriers. 12 More interestingly, 1,4-dithiins can undergo reversible conformation change from the neutral bent structure to its flat radical species via redox regulation. Conceivably, 1,4dithiins are ideal building blocks for composing the desired cyclophanes furnished with both flexibility and stimuliresponsiveness.…”