Unconventional sulfur chemistries for macromolecular syntheses

Sulfur-based reactions play an increasing role in macromolecular syntheses. The present article focuses on recent work from this laboratory that has led to advances in several areas of the field of sulfur chemistry for the synthesis of macromolecular structures with various topologies ranging from linear to networks. Two different classes of photopolymerizations, namely radical and cationic photopolymerizations can be initiated by sulfur-based thioxanthone and triaryl sulfonium salts, respectively. Also described is the structural variation that may affect the spectral sensitivity and efficiency in the related photopolymerizations. An independent part of the article consists of a bird's eye view of various modification processes of polythiophenes. A special emphasis is devoted to the incorporation of polypeptides into these sulfur-based conjugated polymers and their biosensing applications. Thiol-ene chemistry is also discussed in terms of its effect and utilization for the synthesis of telechelic polymers and star copolymers. Finally, recently developed thiol-benzoxazine chemistry offering a facile and an efficient route to exploring the many possibilities in macromolecular synthesis is described.