Boron-Catalyzed Polymerization of Phenyl-Substituted Allylic Arsonium Ylides toward Nonconjugated Emissive Materials from C3/C1 Monomeric Units

Abstract

Two novel allylic arsonium ylide monomers with a phenyl (steric and electronic effect) group at different positions were synthesized and used in boron-catalyzed polymerization to produce a series of well-defined polymers, poly(2-phenylpropenylene-co-2-phenyl-propenylidene) (P2-PhAY) and poly(3phenyl-propenylene-co-3-phenyl-propenylidene) (P3-PhAY), with unusual structures but a controllable molecular weight and relatively low polydispersity. The backbone of these polymers consists of a mixture of C1 (chain grows by one carbon atom at a time) and C3 (chain grows by three carbon atoms at a time) monomeric units, as determined by 1 H, 13 C, and 1 H− 13 C HSQC 2D NMR. Based on the experimental results and density functional theoretical (DFT) calculations, we were able to propose a mechanism that takes into account not only the steric hindrance, but also the electron effect of the phenyl group. In addition, a nontraditional intrinsic luminescence was observed from the nonconjugated P2-PhAY and P3-PhAY; such unexpected emission is attributed to the formation of C3-unit clusters, as evidenced by ultraviolet− visible and fluorescence spectroscopy.

Aluminum-Mediated Polymerization of Allylic Ylides toward α,ω-Functionalized C3 Polymers with Enhanced Nontraditional Intrinsic Luminescence

“…The electron-donating effect was demonstrated to hinder the migration of boron atoms, thus influencing the insertion selectivity of the monomers. 9 These findings indicate a potential direction for regulating the insertion selectivity of the monomer by controlling the acid−base properties of active centers.…”

Organoboron-mediated polymerizations

“…In 2021, the same group studied the steric and electronic effects of C3 arsonium ylide on the polymer backbones. 311 Two novel allylic arsonium ylide monomers with a phenyl group at different positions were used, producing polymers with the C1/C3 mixture backbone, namely, poly(2-phenylpropenylene- co -2-phenyl-propenylidene) (P2-PhAY) and poly(3-phenyl-propenylene- co -3-phenyl-propenylidene) (P3-PhAY). DFT calculations revealed that both the steric and electronic effects guide the C1/C3 monomeric insertion.…”

Unraveling the Influence of the Carbon Skeleton Structure and Substituent Electronic Effects on the Nontraditional Intrinsic Luminescence Properties of Nonconjugated Polyolefins

“…Nevertheless, less attention has been given to other physical properties of novel polyolefins with pure carbon structures such as fluorescence and crystallinity. Recently, pioneering investigations of luminous nonconjugated polyolefins, such as styrene, 44 C3 polyolefins (in which the repeat unit contains three carbon atoms), 45 polyacrylonitrile, 46 and C5 polymers (in which the repeat unit contains five carbon atoms), 47 have been reported, and all of these materials exhibit luminescence. In terms of nonconjugated luminescent polyolefins, in addition to the spatial interactions between molecular chains in the aggregated state, the distance between adjacent conjugated structures in a single chain affects the luminescence, and this phenomenon has rarely been reported.…”