Synthesis of Aromatic Poly(Thioether)s with Phosphine Sulfide Groups for High-Refractive-Index Materials

Ar reaction involving a monomer with a phosphine oxide (PO) group and subsequent conversion of the PO to PS groups using Lawesson's reagent. The poly-(thioether)-s containing the PS groups achieved higher refractive indices, ranging from 1.725 to 1.757 at 589 nm, than the corresponding polymers containing either the PS or thioether moieties. The refractive indices of these poly-((thio)-ether)-s containing the PO or PS groups positively correlate with the heavy heteroatom (S and P) content of the polymers, indicating that the combination of the PS groups and the thioether linkages effectively enhances the refractive indices of the polymers. The above results highlight the potential of the PS group for expanding the structural diversity of polymeric optical materials.