TY - JOUR AU - Probst, Patrick AU - Lindemann, Moritz AU - Bruckner, Johanna R. AU - Atwi, Boshra AU - Wang, Dongren AU - Fischer, Felix R. AU - Högler, Marc AU - Bauer, Matthias AU - Hansen, Niels AU - Dyballa, Michael AU - Buchmeiser, Michael R. TI - Ring-Expansion Metathesis Polymerization under Confinement JO - Journal of the American Chemical Society VL - 147 IS - 10 SN - 0002-7863 CY - Washington, DC PB - ACS Publications M1 - PUBDB-2025-03883 SP - 8741 - 8750 PY - 2025 N1 - ■ ACKNOWLEDGMENTSThe authors acknowledge support by the German Research Foundation (DFG) through grant numbers 358283783�SFB 1333/2 2022 and BU2174/24-1. M.H. and N.H. gratefullyacknowledge the computing time on the high-performance computer HoreKa at the NHR Center at KIT (NHR@KIT). Waiting for fulltext AB - The cationic molybdenum alkylidyne N-heterocyclic carbene (NHC) complex [Mo(C-p-OMeC6H4)(OCMe(CF3)2)2 (IMes)][B(ArF4] (IMes = 1,3-dimesitylimidazol-2-ylidene) was selectively immobilized inside the pores of ordered mesoporous silica (OMS) with pore diameters of 66, 56, and 28 Å and used in the ring-expansion metathesis polymerization (REMP) of cyclic olefins to yield cyclic polymers. A strong confinement effect was observed for cis-cyclooctene (cCOE), 1,5-cyclooctadiene (COD), (+)-2,3-endo,exo-dicarbomethoxynorborn-5-ene ((+)-DCMNBE), and 2-methyl-2-phenylcycloprop-1-ene (MPCP), allowing for the synthesis of low-molecular-weight cyclic polymers even at a high monomer concentration. The exclusive formation of cyclic polymers was demonstrated by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Confinement also influences stereoselectivity, resulting in a pronounced increase in Z-selectivity and in an increased cis-syndiospecificity. LB - PUB:(DE-HGF)16 DO - DOI:10.1021/jacs.4c18171 UR - https://bib-pubdb1.desy.de/record/637657 ER -