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Stereoblock vs Stereoblend: Orchestrating Competing Living Coordination Chain Transfer Polymerizations for the One-Pot Production of New Viscoelastic Grades of Poly(4-methyl-1-pentene)

https://doi.org/10.1021/acscatal.3c05570

Fischbach, Danyon M; Wentz, Charlotte M; Mehdiabadi, Saeid; Soares, João; Sita, Lawrence R (February 2024, ACS Catalysis)

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Highly Versatile Strategy for the Production of Telechelic Polyolefins

https://doi.org/10.1021/acsmacrolett.2c00108

Burkey, Aaron A.; Fischbach, Danyon M.; Wentz, Charlotte M.; Beers, Kathryn L.; Sita, Lawrence R. (March 2022, ACS Macro Letters)

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Migratory Insertion into a Hafnium–Phenyl Bond and a Ligand-Assisted Mechanism for Reversible Chain Transfer in the Living Coordinative Polymerization of Olefins

https://doi.org/10.1021/acs.organomet.2c00364

Kuzminski, Brendan R.; Fischbach, Danyon M.; Yap, Glenn P.; Sita, Lawrence R. (January 2022, Organometallics)

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Versatile Production of Multivariate, Hyperdimensional End Group and Main Chain Functionalized Polyolefins

https://doi.org/10.1002/anie.202304725

Fischbach, Danyon M.; Krstic, Katharina A.; Sita, Lawrence R. (June 2023, Angewandte Chemie International Edition)

Abstract The (stereoselective) living coordinative copolymerization of 1‐alkenes with 4‐aryl‐1,6‐heptadienes, in both the absence and presence of multiple equivalents of a reversible chain transfer agent, is established as a highly versatile strategy for production of multivariate hyperdimensional functionalized semi‐crystalline or amorphous polyolefins that optionally possess either mono‐ or difunctionalized (telechelic) end‐groups in combination with a programmable level of incorporation of orthogonal functional groups within the main‐chain. The non‐conjugated diene comonomers are readily obtained from a diverse range of aryl carboxaldehyde precursors through a one‐step bis‐allylation process. These results serve to provide a new platform for exploring the science and technology of a vast new landscape of functionalized classes of polyolefins that are now accessible in practical and scalable quantities.
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Stereomodulation of Poly(4‐methyl‐1‐pentene): Adoption of a Neglected and Misunderstood Commercial Polyolefin

https://doi.org/10.1002/anie.202211992

Wentz, Charlotte M.; Fischbach, Danyon M.; Sita, Lawrence R. (October 2022, Angewandte Chemie International Edition)

Abstract A toolbox of living coordination polymerization methods based on CPAM group 4 metal initiators has been applied for the stereomodulation of poly(4‐methyl‐1‐pentene) (PMP) tacticity to provide new fundamental forms in which thermal phase transitions,T_gandT_m, can be adjusted over a wide range. Also reported for the first time are the synthesis and properties of authenticated 1,2‐regioregular atactic PMP, which serves to correct past errors regarding this fundamental polyolefin.
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