Quaternization-induced catalyst-free synthesis of viologen-linked ionic polyacetylenes towards heterogeneous catalytic CO₂fixation

Abstract

In this work, we reported a facile catalyst-free and initiator-free strategy to fabricate a new class of viologen-linked ionic polyacetylenes (denoted as VIPAs) that can achieve the simultaneous ionization and...

Stimuli-responsive helical polymeric particles with amplified circularly polarized luminescence

“…As presented in Fig. 6a, there emerged noticeable vibration characteristic vibration peaks of trans C–H (1457 and 1316 cm −1 ), trans C–C (787 cm −1 ), cis C–H (1392 and 1123 cm −1 ), cis polymer (875 cm −1 ), and C–H bonds of naphthalene rings (628 cm −1 ) 59–63 in the FT-IR spectra of P X and P1. The characteristic peaks of cis C–H and the cis polymer in the backbone of P2 were hardly observed.…”

“…Compared with P1, a significant decrease of the second CQO vibration peak and the slight blue-shift of the N-H vibration peak from 1537 to 1541 cm À1 in P X implies that the intramolecular hydrogen bond became weakened between the CQO and N-H bonds due to the existence of dan sulfonamide, wherein the large steric group increased the distance between the side groups. 61,63 However, P 55 had a closer location with P1 at 1538 cm À1 compared to P 91 , P 82 , P 73 , and P 64 , which explains why P 55 incurred new hydrogen bonding, as shown in Fig. 6c.…”

Organocatalytic Polymers from Affordable and Readily Available Building Blocks for the Cycloaddition of CO2 to Epoxides

“…180,181 To obtain readily accessible and inexpensive ionic polymers with the ability to operate under mild reaction conditions, Chen et al carried out the quaternarization of 4,4′bipyridine with propargyl halides at 100 °C in acetonitrile. 182 In place of obtaining discrete monomers, the authors observed the unexpected formation of insoluble and nonporous polyacetylenes (VIPA-X, Scheme 5a) with viologen (C 5 H 4 NR) 2n+ linkers despite the absence of catalysts and polymerization initiators which was attributed to a spontaneous anionic polymerization upon quaternarization. According to TGA and FT-IR analyses, the polymers were found to absorb significant quantities of moisture.…”

A novel crosslinker for synthesizing hypercrosslinked ionic polymers containing activating groups as efficient catalysts for the CO2 cycloaddition reaction

“…8,9 Therefore, it is highly desirable to develop an efficient catalyst to conquer the thermodynamic challenge of inert CO 2 molecules in the cycloaddition reaction. 2,[10][11][12][13] To date, many homogeneous and heterogeneous catalysts have been used in the cycloaddition of CO 2 with epoxides, including ionic liquids (ILs), 14,15 halide-free catalysts, [16][17][18][19] metal complexes, 20,21 bio-based catalysts, 22,23 metal-organic frameworks (MOFs), [24][25][26][27][28][29] porous organic polymers (POPs) [30][31][32][33][34] and cooperative catalysis between them. [35][36][37][38] Some progress has been made in the development of homogeneous catalysts for the CO 2 cycloaddition reaction, and these materials still face the problems of effective adsorption, catalyst recycling, energy consumption and product separation.…”

“…However, the long reaction steps cause a large amount of energy loss in the preparation of the catalyst, and the activating groups are not introduced into the HIPs to activate epoxides and CO 2 . Recently, Chen et al 34 developed a simple strategy to synthesize viologen-linked ionic polyacetylenes in one-pot. The obtained porous ionic polymers (PIPs) with high ionic content showed outstanding catalytic activity for the CO 2 cycloaddition reaction at low temperature and low pressure.…”