A New Class of Conjugated Ionic Polyacetylenes. 3. Cyclopolymerization of Alkyldipropargyl(4-sulfobutyl)ammonium Betaines by Transition Metal Catalysts

Abstract

A new type of conjugated ionic polyacetylene was synthesized by metathesis polymerization of betaine monomers, alkyldipropargyl(4-sulfobutyl)ammonium betaines (ADPSAB). The alkyl groups used are ethyl, n-butyl, n-hexyl, and n-octyl. The polymerization of ADPSAB was carried out with various transition metal catalyst systems such as MoCl5-, WCl6-, and PdCl2-based catalyst systems. The MoCl5 and PdCl2 were found to be particularly effective catalysts for the cyclopolymerization of the betaine monomers. 1 H-NMR, 13 C-NMR, IR, and UV-visible spectroscopies showed that poly(ADPSAB) possess polyene structure having cyclic recurring units in the polymer backbone. Unlike polyelectrolyte, the resulting polymers were more soluble and showed higher viscosities in the salt solution than in salt-free solution (antipolyelectrolytes). When doped with an acceptor such as iodine, the polymers exhibited a substantial increase (∼10 -3 S/cm) in electrical conductivity compared to the undoped state (∼10 -10 S/cm).

Structures and Synthesis of Zwitterionic Polymers

“…This concerns in particular ring opening metathesis polymerization (ROMP), whereas metathesis (cyclo)polymerization of zwitterionic alkynes was reported already some time ago [348]. The new zwitterionic polymers reported have all been based on cycloolefins, mainly on strained tricyclic imides derived from exo-7-oxa-norbornenedicarboxylic acid ( Figure 6) [349][350][351][352][353][354][355][356].…”

Cyclopolymerization

“…A new class of conjugated ionic polyacetylenes has been synthesized by the metathesis cyclopolymerization of alkyldipropargyl(4‐sulfobutyl)ammonium betaines by transition catalysts 34. Monomer and polymer structures are shown in Scheme .…”

Branched 1,2,3-Triazolium-Functionalized Polyacetylene with Enhanced Conductivity

“…The ionic and electronic conductive PAs bearing branched 1,2,3‐triazole ( BTA ) and oligo(ethylene glycol) (OEG) pendants, obtained from the MCP of branched 1,2,3‐triazole‐substituted 1,6‐heptadiyne ( MDTA ), have been realized via both lithium bis(trifluoromethanesulfonyl)imide and iodine doping, and the doped poly( MDTA ) showed the ionic and electronic conductivities of 1.3 × 10 −5 and 2.1 × 10 −7 S cm −1 at 30 °C, respectively, whereas the conductivities of this neutral poly( MDTA ) were not satisfied. Introducing ionic groups into the PA backbone may improve the conductivity, while the application of MCP for ionic 1,6‐heptadiynes to construct iPAs was still rare . Main‐chain self‐doped PAs were subjected to limited freedom to change the ion density and ion species .…”