A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System
Nitriles (N≡CR) are ubiquitous in coordination chemistry, yet literature studies on metal–nitrile bonding based on a multi-technique approach are rare. We selected an easily-available di-organoiron framework, containing both π-acceptor (CO, aminocarbyne) and donor (Cp = η<sup>5</sup>−C&l...
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MDPI AG
2021-11-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/26/23/7088 |
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| author | Giulio Bresciani Lorenzo Biancalana Guido Pampaloni Stefano Zacchini Gianluca Ciancaleoni Fabio Marchetti |
| author_facet | Giulio Bresciani Lorenzo Biancalana Guido Pampaloni Stefano Zacchini Gianluca Ciancaleoni Fabio Marchetti |
| author_sort | Giulio Bresciani |
| collection | DOAJ |
| description | Nitriles (N≡CR) are ubiquitous in coordination chemistry, yet literature studies on metal–nitrile bonding based on a multi-technique approach are rare. We selected an easily-available di-organoiron framework, containing both π-acceptor (CO, aminocarbyne) and donor (Cp = η<sup>5</sup>−C<sub>5</sub>H<sub>5</sub>) ligands, as a suitable system to provide a comprehensive description of the iron–nitrile bond. Thus, the new nitrile <b>(2–12)CF<sub>3</sub>SO<sub>3</sub></b> and the related imine/amine complexes <b>(8–9)CF<sub>3</sub>SO<sub>3</sub></b> were synthesized in 58–83% yields from the respective tris-carbonyl precursors <b>(1a–d)CF<sub>3</sub>SO<sub>3</sub></b>, using the TMNO strategy (TMNO = trimethylamine-N-oxide). The products were fully characterized by elemental analysis, IR (solution and solid state) and multinuclear NMR spectroscopy. In addition, the structures of <b>(2)CF<sub>3</sub>SO<sub>3</sub></b>, <b>(3)CF<sub>3</sub>SO<sub>3</sub></b>, <b>(5)CF<sub>3</sub>SO<sub>3</sub></b> and <b>(11)CF<sub>3</sub>SO<sub>3</sub></b> were ascertained by single crystal X-ray diffraction. Salient spectroscopic data of the nitrile complexes are coherent with the scale of electron-donor power of the R substituents; otherwise, this scale does not match the degree of Fe → N π-back-donation and the Fe–N bond energies, which were elucidated in <b>(2–7)CF<sub>3</sub>SO<sub>3</sub></b> by DFT calculations. |
| first_indexed | 2024-03-10T04:48:33Z |
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| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T04:48:33Z |
| publishDate | 2021-11-01 |
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| spelling | doaj.art-a0be4c912c334322b3e5ae32a9c966cf2023-11-23T02:47:09ZengMDPI AGMolecules1420-30492021-11-012623708810.3390/molecules26237088A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron SystemGiulio Bresciani0Lorenzo Biancalana1Guido Pampaloni2Stefano Zacchini3Gianluca Ciancaleoni4Fabio Marchetti5Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, I-56124 Pisa, ItalyDepartment of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, I-56124 Pisa, ItalyDepartment of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy Interuniversity Consortium for Chemical Reactivity and Catalysis (CIRCC), Via Celso Ulpiani 27, I-70126 Bari, ItalyDepartment of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, I-56124 Pisa, ItalyDepartment of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, I-56124 Pisa, ItalyNitriles (N≡CR) are ubiquitous in coordination chemistry, yet literature studies on metal–nitrile bonding based on a multi-technique approach are rare. We selected an easily-available di-organoiron framework, containing both π-acceptor (CO, aminocarbyne) and donor (Cp = η<sup>5</sup>−C<sub>5</sub>H<sub>5</sub>) ligands, as a suitable system to provide a comprehensive description of the iron–nitrile bond. Thus, the new nitrile <b>(2–12)CF<sub>3</sub>SO<sub>3</sub></b> and the related imine/amine complexes <b>(8–9)CF<sub>3</sub>SO<sub>3</sub></b> were synthesized in 58–83% yields from the respective tris-carbonyl precursors <b>(1a–d)CF<sub>3</sub>SO<sub>3</sub></b>, using the TMNO strategy (TMNO = trimethylamine-N-oxide). The products were fully characterized by elemental analysis, IR (solution and solid state) and multinuclear NMR spectroscopy. In addition, the structures of <b>(2)CF<sub>3</sub>SO<sub>3</sub></b>, <b>(3)CF<sub>3</sub>SO<sub>3</sub></b>, <b>(5)CF<sub>3</sub>SO<sub>3</sub></b> and <b>(11)CF<sub>3</sub>SO<sub>3</sub></b> were ascertained by single crystal X-ray diffraction. Salient spectroscopic data of the nitrile complexes are coherent with the scale of electron-donor power of the R substituents; otherwise, this scale does not match the degree of Fe → N π-back-donation and the Fe–N bond energies, which were elucidated in <b>(2–7)CF<sub>3</sub>SO<sub>3</sub></b> by DFT calculations.https://www.mdpi.com/1420-3049/26/23/7088coordination chemistrynitrile ligandmetal–nitrile bondingπ-back-donationdiiron complexesDFT calculations |
| spellingShingle | Giulio Bresciani Lorenzo Biancalana Guido Pampaloni Stefano Zacchini Gianluca Ciancaleoni Fabio Marchetti A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System Molecules coordination chemistry nitrile ligand metal–nitrile bonding π-back-donation diiron complexes DFT calculations |
| title | A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System |
| title_full | A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System |
| title_fullStr | A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System |
| title_full_unstemmed | A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System |
| title_short | A Comprehensive Analysis of the Metal–Nitrile Bonding in an Organo-Diiron System |
| title_sort | comprehensive analysis of the metal nitrile bonding in an organo diiron system |
| topic | coordination chemistry nitrile ligand metal–nitrile bonding π-back-donation diiron complexes DFT calculations |
| url | https://www.mdpi.com/1420-3049/26/23/7088 |
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