Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• by radical unzipping depolymerization under photon or β-irradiation (Scheme 20a). Similarly, poly(olefin sulfone) undergoes depolymerization upon irradiation of light or electron beams [193][194]. It is an alternating copolymer of 1-olefins and SO2, and therefore the decomposition products are mostly

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• substituents. We envisaged that such an alternating copolymer in perfect regularity can be achieved by deprotonative polymerization employing a bithiophene with different substituents at the 3- and 3'-position. We have recently shown that the coupling of 2-chloro-3-substituted thiophene 2 with 2-bromo-3

• also examined preliminarily, and it was confirmed that the alternating copolymer was obtained with extremely high regularity. Herein, we wished to study the polymerization of bithiophene 4 possessing several kinds of substituents and a variety of functionalities. Since the homopolymer is considered

• result in much inferior solubility as compared to the alternating copolymer. Several chlorobithiophenes 4 were then similarly subjected to the polymerization. The results of the alternating copolymerizations are summarized in Scheme 4. The deprotonation by the Knochel–Hauser base was carried out at room

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• role in the formation of alternating diads. Indeed, the proportion of alternating copolymer increases moving from the small methyl group (54) to the large cyclohexyl group (56). Unsymmetrical catalysts based on NHC units possessing one alkyl substituent (propyl (59) or benzyl (60)) and one mesityl

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• copolymerized at 30 °C to afford a completely alternating copolymer, while the TOF (61 h−1) was much lower than that obtained for the PO/PA copolymerization (Table 2, entry 1). A higher polymerization temperature improved the TOF up to 399 h−1 and almost complete conversion of PA was achieved within 1 h (Table

•  2, entry 2). The copolymerization with cyclohexene oxide (CHO), a common alicyclic epoxide in epoxide/CA copolymerization, also gave the corresponding alternating copolymer (Table 2, entries 3 and 4). The TOF of 244 h−1 was achieved at 60 °C, which was the highest one ever reported for a CHO/PA

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• -transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). Keywords: carbon dioxide; CO2 chemistry; cobalt complex; phthalic anhydride; propylene oxide; terpolymerization; Introduction Carbon dioxide (CO2) can be utilized to prepare aliphatic polycarbonates through coupling reactions

• alternating copolymer (40 °C), but lower than that of the PO/PA alternating polymer (65 °C) (Figure 3). With a small number of incorporated PA units (fPA, ca. 0.1), Tg was similar to that of the PO/CO2 alternating copolymer (entries 4, 13–15). For the polymers generated at the early stage (1.5 h), two Tg

• terpolymer bearing a substantial number of PA units (fPA, 0.23) showed a higher Tg value (48 °C) than the CO2/PO alternating copolymer (40 °C). Experimental General remarks. CO2 gas (99.999% purity) was dried through storage in a column of molecular sieves 3Å at a pressure of 30 bar. PO was dried by stirring

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• polymer in solution was bathochromically shifted by 12 nm with the maximum at 488 nm. The polymer also showed a bright red fluorescence with the maximum at 544 nm. In addition to the alternating copolymer, copolymers with lower DPP content were also prepared. All copolymers showed the DPP absorption at