N-Heterocyclic Carbene and Cyclic (Alkyl)(amino)carbene Complexes of Titanium(IV) and Titanium(III)
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- The reaction of one and two equivalents of the N ‐heterocyclic carbene IMes [IMes = 1,3‐bis(2,4,6‐trimethyl‐phenyl)imidazolin‐2‐ylidene] or the cyclic (alkyl)(amino)carbene cAAC\(^{Me}\) [cAAC\(^{Me}\) = 1‐(2,6‐diisopropyl‐phenyl)‐3,3,5,5‐tetra‐methylpyrrolidin‐2‐ylidene] with [TiCl\(_{4}\)] in n ‐hexane results in the formation of mono‐ and bis‐carbene complexes [TiCl\(_{4}\)(IMes)] 1 , [TiCl\(_{4}\)(IMes)2] 2 , [TiCl\(_{4}\)(cAAC\(^{Me}\))] 3 , and [TiCl\(_{4}\)(cAAC\(^{Me}\))\(_{2}\)] 4 , respectively. For comparison, the titanium(IV) NHCThe reaction of one and two equivalents of the N ‐heterocyclic carbene IMes [IMes = 1,3‐bis(2,4,6‐trimethyl‐phenyl)imidazolin‐2‐ylidene] or the cyclic (alkyl)(amino)carbene cAAC\(^{Me}\) [cAAC\(^{Me}\) = 1‐(2,6‐diisopropyl‐phenyl)‐3,3,5,5‐tetra‐methylpyrrolidin‐2‐ylidene] with [TiCl\(_{4}\)] in n ‐hexane results in the formation of mono‐ and bis‐carbene complexes [TiCl\(_{4}\)(IMes)] 1 , [TiCl\(_{4}\)(IMes)2] 2 , [TiCl\(_{4}\)(cAAC\(^{Me}\))] 3 , and [TiCl\(_{4}\)(cAAC\(^{Me}\))\(_{2}\)] 4 , respectively. For comparison, the titanium(IV) NHC complex [TiCl\(_{4}\)(Ii Pr\(^{Me}\))] 5 (Ii Pr\(^{Me}\) = 1,3‐diisopropyl‐4,5‐dimethyl‐imidazolin‐2‐ylidene) has been synthesized and structurally characterized. The reaction of [TiCl\(_{4}\)(IMes)] 1 with PMe\(_{3}\) affords the mixed substituted complex [TiCl\(_{4}\)(IMes)(PMe\(_{3}\))] 6 . The reactions of [TiCl\(_{3}\)(THF)\(_{3}\)] with two equivalents of the carbenes IMes and cAAC\(^{Me}\) in n ‐hexane lead to the clean formation of the titanium(III) complexes [TiCl\(_{3}\)(IMes)\(_{2}\)] 7 and [TiCl\(_{3}\)(cAAC\(^{Me}\))\(_{2}\)] 8 . Compounds 1 –8 have been completely characterized by elemental analysis, IR and multinuclear NMR spectroscopy and for 2 –5 , 7 and 8 by X‐ray diffraction. Magnetometry in solution, EPR and UV/Vis spectroscopy and DFT calculations performed on 7 and 8 are indicative of a predominantly metal‐centered d\(^{1}\)‐radical in both cases.…
Autor(en): | Günther Horrer, Mirjam J. Krahfuß, Katharina Lubitz, Ivo Krummenacher, Holger BraunschweigORCiD, Udo Radius |
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URN: | urn:nbn:de:bvb:20-opus-208725 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Fakultät für Chemie und Pharmazie / Institut für Anorganische Chemie |
Sprache der Veröffentlichung: | Englisch |
Titel des übergeordneten Werkes / der Zeitschrift (Englisch): | European Journal of Inorganic Chemistry |
Erscheinungsjahr: | 2020 |
Band / Jahrgang: | 2020 |
Heft / Ausgabe: | 3 |
Seitenangabe: | 281-291 |
Originalveröffentlichung / Quelle: | European Journal of Inorganic Chemistry 2020(3), 281–291. DOI: 10.1002/ejic.201901207 |
DOI: | https://doi.org/10.1002/ejic.201901207 |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 5 Naturwissenschaften und Mathematik / 54 Chemie / 546 Anorganische Chemie |
Freie Schlagwort(e): | N-heterocyclic carbenes; Titanium; carbene ligands; structure elucidation |
Datum der Freischaltung: | 23.09.2020 |
Lizenz (Deutsch): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |