Dynamic processes of the first NHC-substituted rhenium heptahydrides [ReH <sub>7</sub> (NHC) <sub>2</sub> ]
In this paper are presented possible geometries and fluxional mechanisms of three [ReH<sub>7</sub>(NHC)<sub>2</sub>] complexes (NHC = IMes (1) (1,3-bis(2,4,6-trimethyl phenyl) imidazol-2-ylidene), IMesCl<sub>2</sub> (2) (4,5-dichloro-1,3-dihydro-1,3-bis(2,4,6-trimethylphenyl)-2<i>H</i>-imidazol-2-ylidene), BIMes (3) (1,3-bis(2,4,6-trimethylphenyl)-benzo imidazole ylidene)). Using DFT calculations, plausible fluxional processes were proposed, and a new process named "η<sup>2</sup>-quadratic twist" has been identified. For 2 the intermediate complex [Re(H)<sub>5</sub>(η<sup>2</sup>-H<sub>2</sub>)(IMesCl<sub>2</sub>)<sub>2</sub>] proved to be more energetically accessible at RT than those of the complexes 1 ([Re(H)<sub>5</sub>(η<sup>2</sup>-H<sub>2</sub>)(IMes)<sub>2</sub>]) and 3 ([Re(H)<sub>5</sub>(η<sup>2</sup>-H<sub>2</sub>)(BIMes)<sub>2</sub>]). Two different fluxional mechanisms have been proposed: the first one for 1 and 3, and the second one for 2. The mechanism for complex 2 implies the C-H activation of the hydrogens of the <i>o</i>-CH<sub>3</sub> group of the IMesCl<sub>2</sub> ligands.
Authors
- Marco Pierini (ORCID: https://orcid.org/0000-0003-4030-8205)
- Adriano Pierini (ORCID: https://orcid.org/0000-0002-8863-503X)
- Pasquale Gabriele Grieco (ORCID: https://orcid.org/0000-0002-2789-4302)
Institutions
- ZHAW Zurich University of Applied Sciences (CH)
- University of Zurich (CH)
- Sapienza University of Rome (IT)
Publication Details
- Journal
- Dalton Transactions
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5dt01655j
- Citations
- 2
- Primary Topic
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Type
- article
- Field-Weighted Citation Impact
- 1.87