Bridged Aromatic Oxo- and Thioethers with Intense Emission in Solution and the Solid State

Design Concepts for Solution and Solid-State Emitters - A Modern Viewpoint on Classical and Non-Classical Approaches

For a long time, luminescence phenomena were strictly distinguished between the emission of isolated molecules in dilute solutions or close-packed structures such as in powders or aggregates. This changed with the breakthrough observation of dual-state efficient materials, which led to a rapid boost of publications examining the influence of structural features to achieve balanced emission with disregarded molecular surroundings. Some first general structural design concepts have already been proposed based on reoccurring patterns and pivotal motifs. However, we have found another way to classify these solution and solid-state emitters (SSSEs). Hence, this minireview aims to present an overview of published structural features of SSSEs while shining light on design concepts from a more generalized perspective. Since SSSEs are believed to bridge the gap of hitherto known aggregation-sensitive compound classes, we hope to give future scientists a versatile tool in hand to efficiently design novel luminescent materials.

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 1,4-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 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