dc.contributor.author | Hollfelder, Christoph O. | |
dc.contributor.author | Meermann-Zimmermann, Melanie | |
dc.contributor.author | Spiridopoulos, Georgios | |
dc.contributor.author | Werner, Daniel | |
dc.contributor.author | Törnroos, Karl Wilhelm | |
dc.contributor.author | Maichle-Mössmer, Cäcilia | |
dc.contributor.author | Anwander, Reiner | |
dc.date.accessioned | 2020-03-18T12:57:22Z | |
dc.date.available | 2020-03-18T12:57:22Z | |
dc.date.issued | 2019 | |
dc.Published | Hollfelder, Meermann-Zimmermann, Spiridopoulos, Werner, Törnroos, Maichle-Mössmer, Anwander. C–H-Bond Activation and Isoprene Polymerization Studies Applying Pentamethylcyclopentadienyl-Supported Rare-Earth-Metal Bis(Tetramethylaluminate) and Dimethyl Complexes. Molecules. 2019;24(20):3703 | eng |
dc.identifier.issn | 1420-3049 | en_US |
dc.identifier.uri | https://hdl.handle.net/1956/21528 | |
dc.description.abstract | As previously shown for lutetium and yttrium, 1,2,3,4,5-pentamethylcyclopentadienyl (C5Me5 = Cp*)-bearing rare-earth metal dimethyl half-sandwich complexes [Cp*LnMe2]3 are now also accessible for holmium, dysprosium, and terbium via tetramethylaluminato cleavage of [Cp*Ln(AlMe4)2] with diethyl ether (Ho, Dy) and tert-butyl methyl ether (TBME) (Tb). C–H-bond activation and ligand redistribution reactions are observed in case of terbium and are dominant for the next larger-sized gadolinium, as evidenced by the formation of mixed methyl/methylidene clusters [(Cp*Ln)5(CH2)(Me)8] and metallocene dimers [Cp*2Ln(AlMe4)]2 (Ln = Tb, Gd). Applying TBME as a “cleaving” reagent can result in both TBME deprotonation and ether cleavage, as shown for the formation of the 24-membered macrocycle [(Cp*Gd)2(Me)(CH2OtBu)2(AlMe4)]4 or monolanthanum complex [Cp*La(AlMe4){Me3Al(CH2)OtBu}] and monoyttrium complex [Cp*Y(AlMe4)(Me3AlOtBu)], respectively. Complexes [Cp*Ln(AlMe4)2] (Ln = Ho, Dy, Tb, Gd) and [Cp*LnMe2]3 (Ln = Ho, Dy) are applied in isoprene and 1,3-butadiene polymerization, upon activation with borates [Ph3C][B(C6F5)4] and [PhNHMe2][B(C6F5)4], as well as borane B(C6F5)3. The trans-directing effect of AlMe3 in the binary systems [Cp*Ln(AlMe4)2]/borate is revealed and further corroborated by the fabrication of high-cis-1,4 polybutadiene (97%) with “aluminum-free” [Cp*DyMe2]3/[Ph3C][B(C6F5)4]. The formation of multimetallic active species is supported by the polymerization activity of pre-isolated cluster [(Cp*Ho)3Me4(CH2)(thf)2]. | en_US |
dc.language.iso | eng | eng |
dc.publisher | MDPI | en_US |
dc.rights | Attribution CC BY | eng |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0 | eng |
dc.title | C–H-Bond Activation and Isoprene Polymerization Studies Applying Pentamethylcyclopentadienyl-Supported Rare-Earth-Metal Bis(Tetramethylaluminate) and Dimethyl Complexes | en_US |
dc.type | Peer reviewed | |
dc.type | Journal article | |
dc.date.updated | 2020-01-02T09:24:09Z | |
dc.description.version | publishedVersion | en_US |
dc.rights.holder | Copyright 2019 The Author(s) | en_US |
dc.identifier.doi | https://doi.org/10.3390/molecules24203703 | |
dc.identifier.cristin | 1764959 | |
dc.source.journal | Molecules | |