Boron-Catalyzed C1 Copolymerization of Arsonium and Sulfoxonium Ylides toward Unrepresented Structures and Fluorescence Properties.

The first synthesis of well-defined poly(methylene-co-1,1-diphenylpropenenylene) (C1-co-C1'), equivalent to poly(ethylene-co-diphenylbutadiene) copolymer was accomplished by C1 copolymerization of novel diphenylpropenyl triphenyl arsonium ylides (Ph2AY) and dimethylsulfoxonium methylide (Me2SY) using B-thexylborepane as an initiator. All polymerization conditions, including feed ratio, temperature, and reaction time, were optimized. A series of photoluminescent poly(ethylene-co-diphenylbutadiene) were synthesized at different feed ratios, opening a new synthetic horizon for poly(ethylene-co-disubstitutedbutadiene). Notably, a new C1 segment, resulting from a double bond rearrangement, was confirmed by  NMR, resulting in an unprecedented two-monomer three-structure random terpolymer. An unexpected red-shift phenomenon in the fluorescence spectra was observed with an increase in the ratio of Ph2AY in the copolymer. This shift is attributed to the aggregation of diphenylbutadiene segment, akin to through-space conjugation (TSC), likely induced by a decrease in the crystallinity of copolymers. Furthermore, another disubstituted allylic triphenyl arsonium ylides, (E)-2-phenylbutenyl triphenyl arsonium ylide (MePhAY) was also synthesized and investigated. These additional compounds expand knowledge and potential applications of such copolymerization techniques in advanced materials.