@article{a8f05dd6cd3041aab63baed50f6447f1,
title = "Beyond the Active Site. Cp*ZrMe3/Sulfated Alumina-Catalyzed Olefin Polymerization Tacticity via Catalyst⋅⋅⋅Surface Ion-Pairing",
abstract = "Surface-bound organometallic molecules have recently enabled the development of single-site heterogeneous catalysts, advancing the atomic scale understanding and diversity of heterogeneous catalysis. Here we report that supporting Cp*ZrMe3 (Cat1) on acidic sulfated-alumina (AlS) affords the surface catalyst Cat1/AlS, which was characterized by multi-dimensional solid-state NMR spectroscopies, and is active in ethylene homo- and copolymerizations, as well as propylene and 1-hexene homopolymerizations. In contrast to propylene (or 1-hexene) polymerization by homogeneous Cp*ZrMe2+ B(C6F5)4− which yields atactic polyolefins, Cat1/AlS promotes remarkable isotacticity with mmmm >95 %. Complementary DFT analysis argues that the restrictive local Cat1/AlS C1-symmetry favors activation and enchainment at the propylene re enantioface, promoting isotactic polymerization via a “back-skip-like” mechanism.",
keywords = "Zirconocene, isotactic polypropylene, olefin polymerization, solid-state NMR, surface organometallics",
author = "Jialong Zhang and Mason, {Alexander H.} and Yang Wang and Alessandro Motta and Takeshi Kobayashi and Marek Pruski and Yanshan Gao and Marks, {Tobin J.}",
note = "Funding Information: Financial support by Office of Basic Energy Sciences, DOE under grant DE-FG02-03ER15457 to the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University (J.Z., A.M., T.M.) is gratefully acknowledged. Computational resources were provided by Northwestern University Quest High Performance Computing Cluster and CINECA award no. HP10CC5WSY 2020 under the ISCRA initiative; NMR instrumentation at IMSERC was supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633), Int. Institute of Nanotechnology, and Northwestern University. Solid-state NMR experiments were supported at Ames Laboratory by the U.S. DOE, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. Ames Laboratory is operated for the DOE by Iowa State University under contract No. DE-AC02-07CH11358. Funding Information: Financial support by Office of Basic Energy Sciences, DOE under grant DE‐FG02‐03ER15457 to the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University (J.Z., A.M., T.M.) is gratefully acknowledged. Computational resources were provided by Northwestern University Quest High Performance Computing Cluster and CINECA award no. HP10CC5WSY 2020 under the ISCRA initiative; NMR instrumentation at IMSERC was supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS‐2025633), Int. Institute of Nanotechnology, and Northwestern University. Solid‐state NMR experiments were supported at Ames Laboratory by the U.S. DOE, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. Ames Laboratory is operated for the DOE by Iowa State University under contract No. DE‐AC02‐07CH11358. Publisher Copyright: {\textcopyright} 2021 Wiley-VCH GmbH",
year = "2021",
month = jun,
day = "8",
doi = "10.1002/cctc.202100406",
language = "English (US)",
volume = "13",
pages = "2564--2569",
journal = "ChemCatChem",
issn = "1867-3880",
publisher = "Wiley - VCH Verlag GmbH & CO. KGaA",
number = "11",
}