121091 20240319080957.0 doi 10.1039/d1py01650d sideral 131640 ART-2022-131640 eng Angoy, Marta Polymerization of phenylacetylene catalyzed by rhodium(<scp>i</scp>) complexes with <i>N</i>-functionalized N-heterocyclic carbene ligands 2022 Access copy available to the general public Unrestricted A series of neutral [RhX(nbd)(κC-MeIm∩Z)] and cationic [Rh(nbd)(κ2C,N-MeIm∩Z)]+ (X = Cl, Br; MeIm = 3-methylimidazol-2-yliden-1-yl; ∩Z = N-functionalized wingtip; nbd = 2,5-norbornadiene) complexes featuring NHC ligands functionalized with a 1-aminopropyl, 3-dimethylaminopropyl, pyridin-2-ylmethyl, or quinolin-8-ylmethyl substituent have been prepared. These complexes efficiently catalyze the polymerization of phenylacetylene without base as a co-catalyst affording stereoregular polyphenylacetylenes of very high molar mass. Polymers of Mw up to 2 × 106 g mol−1 and moderate dispersity have been prepared with neutral chloro-complexes having aminopropyl wingtips. Catalyst precursors bearing functionalized NHC ligands with a flexible amino-alkyl wingtip are significantly more active than those having a heterocyclic substituent. These complexes are in general much more active than related compounds having N-functionalized phosphine ligands. Polymer characterization by SEC/MALS/DRI analysis has revealed the presence of a fraction of branched polymer of high molar mass in most samples obtained with catalysts having N-heterocyclic substituents at the NHC ligand. The N-donor function at the NHC ligand likely behaves as an internal base for the deprotonation of phenylacetylene to give the initiating alkynyl cationic [Rh(nbd)(C[triple bond, length as m-dash]C-Ph)(κC-MeIm∩ZH)]+ species. However, the participation of neutral alkynyl species [Rh(nbd)(C[triple bond, length as m-dash]C-Ph)(κC-MeIm∩Z)] should be considered in order to rationalize the notable catalytic activity of some neutral chloro-complexes. info:eu-repo/grantAgreement/ES/DGA-FSE/E42-20R info:eu-repo/grantAgreement/ES/MICINN/PID2019-103965GB-I00/AEI/10.13039/501100011033 info:eu-repo/semantics/openAccess by-nc http://creativecommons.org/licenses/by-nc/3.0/es/ 4.6 2022 POLYMER SCIENCE 18 / 85 = 0.212 2022 Q1 T1 1.014 2022 Biomedical Engineering 2022 Q1 Bioengineering 2022 Q1 Polymers and Plastics 2022 Q1 Organic Chemistry 2022 Q1 Biochemistry 2022 Q2 8.6 2022 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Jiménez, M. Victoria (orcid)0000-0002-0545-9107 Lahoz, Fernando J. Vispe, Eugenio (orcid)0000-0002-4921-4734 Pérez-Torrente, Jesús J. Universidad de Zaragoza (orcid)0000-0002-3327-0918 2010 760 Universidad de Zaragoza Dpto. Química Inorgánica Área Química Inorgánica 13, 10 (2022), 1411-1421 POLYMER CHEMISTRY POLYMER CHEMISTRY 1759-9954 2267449 http://zaguan.unizar.es/record/121091/files/texto_completo.pdf Versión publicada 2888335 http://zaguan.unizar.es/record/121091/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:121091 articulos driver 2024-03-18-13:41:45 ARTICLE