Metal-Free Alkyne Polyhydrothiolation: Synthesis of Functional Poly(vinylenesulfide)s with High Stereoregularity by Regioselective Thioclick Polymerization

A new synthetic route to sulfur-rich polymers has been developed. The alkynepolyhydrothiolations of 4,4(-thiodibenzenethiol (1) and arylene dipropiolates(2–5) mediated by amines proceed at room temperature in a regioselectivefashion, furnishin g sole anti-Markovnikov products of poly(vinylenesulfide)s(P1/2–P1/5) with high molecular weights (Mwup to 32 300) and highstereoregularities (Z content up to 81.4%) in high yields (up to 98.2%).Polymers P1/2–P1/4 are soluble in common organic solve nts. They areoptically transparent, allowing almost all visible and IR light to transmitthrough. Thanks to the high sulfur contents of the polymers, their films showhigh refractive indic es (n ¼ 1.73–1.70) in the wavele ngth region of 500–1700 nm as well as high Abbe´numbers (nD' up to 539) and low opticaldispersions (D' down to 0.002) at wavelengths important fortelecommunications. Their refractivities can be further enhanced (n up to2.06) by metal complexation and their films can be crosslinked by UVirradiation, which enables ready fabrication of fluorescent photopatterns