127879 20231023120953.0 doi 10.1021/acs.organomet.8b00430 sideral 107933 ART-2018-107933 eng Angoy, M. Mechanistic Investigation on the Polymerization of Phenylacetylene by 2-Diphenylphosphinopyridine Rhodium(I) Catalysts: Understanding the Role of the Cocatalyst and Alkynyl Intermediates 2018 The mono- and dinuclear rhodium(I) complexes featuring 2-(diphenylphosphino)pyridine ligands, [Rh(cod)(Ph2PPy)(+) and [Rh(nbd)(mu-Ph2PPY)(2)(2+) (cod = 1, 5-cyclooctadiene, nbd = 2, 5-norbornadiene), have been prepared in order to be evaluated as phenylacetylene (PA) polymerization catalysts. In contrast with compound [Rh(nbd){Ph2P(CH2)(2)Py}(+), featuring a 2 -(2-(diphenylphosphino)ethyl)pyridine ligand, that showed a moderate catalytic activity, both [Rh(diene)(Ph2PPy)](n)(n+) (n = 1, cod; n = 2, nbd) complexes showed no catalytic activity due to the formation of unusual dinuclear species [Rh-2(diene)(2)(mu-Ph2PPy)(mu-C=C-R))+, supported by a Ph2PPy bridging ligand and an alkynyl ligand coordinated in a mu-eta(1):eta(2) fashion, which are inactive in PA polymerization. However, compounds [Rh(diene)(Ph2PPy)](n)(n+) efficiently polymerize PA in the presence of a cocatalyst as iPrNH(2) affording highly stereoregular poly(phenylacetylene) (PPA) of My, = 3.42 X 10(5) (cod) and 2.02 X 10(5) (nbd) with polydispersities of 1.39 and initiation efficiencies of 4-7%. NMR studies on the polymerization reaction have allowed identification of the alkynyl species [Rh(C equivalent to CPh)(cod)(Ph2PPy)] as the likely initiating species involved in the generation of the rhodium-vinyl species responsible for the propagation step. The iPrNH(2) cocatalyst is possibly involved in the efficient proton transfer from the coordinated PA to iPrNH(2) that allows for a significant concentration of the key initiating species [Rh(C-CPh)(cod)(Ph2PPy)]. The distinct behavior of compounds [Rh(diene)(Ph2PPy)](n)(n+) as PA polymerization catalysts is a consequence of the binucleating ability of the Ph2PPy ligand in combination with the low basicity of the pyridine fragment which allows for the stabilization of the inactive alkynyl-bridge dinuclear species. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/MINECO-FEDER/CTQ2013-42532-P info:eu-repo/grantAgreement/ES/MINECO-FEDER/CTQ2016-75884-P info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 4.1 2018 CHEMISTRY, ORGANIC 11 / 57 = 0.193 2018 Q1 T1 CHEMISTRY, INORGANIC & NUCLEAR 5 / 45 = 0.111 2018 Q1 T1 1.473 2018 Inorganic Chemistry 2018 Q1 Physical and Theoretical Chemistry 2018 Q1 Organic Chemistry 2018 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Jimenez, M.V. Universidad de Zaragoza (orcid)0000-0002-0545-9107 Modrego, F.J. Universidad de Zaragoza (orcid)0000-0002-9633-3285 Oro, L.A. Universidad de Zaragoza (orcid)0000-0001-7154-7239 Passarelli, V. Perez-Torrente, J.J. Universidad de Zaragoza (orcid)0000-0002-3327-0918 2010 760 Universidad de Zaragoza Dpto. Química Inorgánica Área Química Inorgánica 37, 16 (2018), 2778-2794 Organometallics Organometallics 0276-7333 1267628 http://zaguan.unizar.es/record/127879/files/texto_completo.pdf Postprint 2967437 http://zaguan.unizar.es/record/127879/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:127879 articulos driver 2023-10-23-11:03:22 ARTICLE