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Bresciani G, Ciancaleoni G, Zacchini S, Biancalana L, Pampaloni G, Funaioli T, Marchetti F. Mixed valence triiron complexes from the conjugation of [Fe IFe I] and [Fe II] complexes via intermolecular carbyne/alkyne coupling. Dalton Trans 2024; 53:4299-4313. [PMID: 38345429 DOI: 10.1039/d4dt00079j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
We present a new synthetic strategy for obtaining mixed-valence triiron complexes where the metal centers are bridged by a novel, highly functionalized hydrocarbyl ligand. The alkynyl-vinyliminium complexes [Fe2Cp2(CO)(μ-CO){μ-η1:η3-C(X-CCH)CHCNMe2}]CF3SO3 (X = 4-C6H4, [2a1]CF3SO3; X = (CH2)3, [2a2]CF3SO3) were synthesized in almost quantitative yields from the aminocarbyne precursor [Fe2Cp2(CO)2(μ-CO){μ-CNMe2}]CF3SO3, [1a]CF3SO3, and the di-alkynes HCC-X-CCH. Then, the ferracycle [Fe(Cp)(CO){C(NMe2)CHC(4-C6H4CCH)C(O)}], 4a1, was produced in 47% yield from the cleavage of [2a1]CF3SO3 promoted by pyrrolidine. Subsequent reactions of the acetonitrile adducts [Fe2Cp2(CO)(μ-CO)(NCMe){μ-CNMe(R)}]CF3SO3 (R = Me, [1aACN]CF3SO3; R = Xyl, [1bACN]CF3SO3) ([FeIFeI]) with 4a1 ([FeII]) at room temperature resulted in the formation of [FeIFeIFeII] complexes [Fe2Cp2(CO)(μ-CO){μ-η1:η3-C(X-CCHC(NMe2)FeCp(CO)CO)CHCNMe(R)}]CF3SO3 (R = Me, [5a1]CF3SO3; R = Xyl, [5b1]CF3SO3) in yields ranging from 56% to 64%. The new products were characterized by IR and multinuclear NMR spectroscopy, and the structures of [2a2]CF3SO3 and 4a1 were confirmed by single crystal X-ray diffraction. Cyclic voltammetry and spectroelectrochemical studies on [5a1]+ have revealed that reduction and oxidation events occur almost independently at the [FeIFeI] and [FeII] units, respectively. This observation underscores a minimal electronic interaction between the two fragments within the triiron complex. Accordingly, DFT studies pointed out that the HOMO and LUMO orbitals are predominantly localized in the two distinct compartments of [5a1]+.
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Affiliation(s)
- Giulio Bresciani
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Gianluca Ciancaleoni
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Stefano Zacchini
- University of Bologna, Department of Industrial Chemistry "Toso Montanari", Viale Risorgimento 4, I-40136 Bologna, Italy
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Lorenzo Biancalana
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Guido Pampaloni
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Tiziana Funaioli
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Fabio Marchetti
- University of Pisa, Department of Chemistry and Industrial Chemistry, Via G. Moruzzi 13, I-56124 Pisa, Italy.
- CIRCC, Via Celso Ulpiani 27, I-70126 Bari, Italy
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Hall MR, Moggach SA, Low PJ. Syntheses and Structures of trans-bis(Alkenylacetylide) Ruthenium Complexes. Chem Asian J 2021; 16:3385-3403. [PMID: 34468081 DOI: 10.1002/asia.202100850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/25/2021] [Indexed: 11/08/2022]
Abstract
A series of ruthenium alkenylacetylide complexes trans-[Ru{C≡CC(=CH2 )R}Cl(dppe)2 ] (R=Ph (1 a), c C4 H3 S (1 b), 4-MeS-C6 H4 (1 c), 3,3-dimethyl-2,3-dihydrobenzo[b]thiophene (DMBT) (1 d)) or trans-[Ru{C≡C-c C6 H9 }Cl(dppe)2 ] (1 e) were allowed to react with the corresponding propargylic alcohol HC≡CC(Me)R(OH) (R=Ph (A), c C4 H3 S (B), 4-MeS-C6 H4 (C), DMBT (D) or HC≡C-c C6 H10 (OH) (E) in the presence of TlBF4 and DBU to presumably give alkenylacetylide/allenylidene intermediates trans-[Ru{C≡CC(=CH2 )R}{C=C=C(Me)}(dppe)2 ]PF6 ([2]PF6 ). These complexes were not isolated but deprotonated to give the isolable bis(alkenylacetylide) complexes trans-[Ru{C≡CC(=CH2 )R}2 (dppe)2 ] (R=Ph (3 a), c C4 H3 S (3 b), 4-MeS-C6 H4 (3 c), DMBT (3 d)) and trans-[Ru{C≡C-c C6 H9 }2 (dppe)2 ] (3 e). Analogous reactions of trans-[Ru(CH3 )2 (dmpe)2 ], featuring the more electron-donating 1,2-bis(dimethylphosphino)ethane (dmpe) ancillary ligands, with the propargylic alcohols A or C and NH4 PF6 in methanol allowed isolation of the intermediate mixed alkenylacetylide/allenylidene complexes trans-[Ru{C≡CC(=CH2 )R}{C=C=C(Me)}(dmpe)2 ]PF6 (R=Ph ([4 a]PF6 ), 4-MeS-C6 H4 ([4 c]PF6 ). Deprotonation of [4 a]PF6 or [4 c]PF6 gave the symmetric bis(alkenylacetylide) complexes trans-[Ru{C≡CC(=CH2 )R}2 (dmpe)2 ] (R=Ph (5 a), 4-MeS-C6 H4 (5 c)), the first of their kind containing the dmpe ancillary ligand sphere. Attempts to isolate bis(allenylidene) complexes [Ru{C=C=C(Me)R}2 (PP)2 ]2+ (PP=dppe, dmpe) from treatment of the bis(alkenylacetylide) species 3 or 5 with HBF4 ⋅ Et2 O were ultimately unsuccessful.
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Affiliation(s)
- Michael R Hall
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
| | - Stephen A Moggach
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
| | - Paul J Low
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
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Guschlbauer J, Shaughnessy KH, Pietrzak A, Chung MC, Sponsler MB, Kaszyński P. [closo-B10H8-1,10-(CN)2]2– as a Conduit of Electronic Effects: Comparative Studies of Fe···Fe Communication in [{(η5-Cp)(dppe)Fe}2{μ2-(NC-X-CN)}]n+ (n = 0, 2). Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00269] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Jannick Guschlbauer
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-001 Łódź, Poland
| | - Kevin H. Shaughnessy
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-001 Łódź, Poland
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Anna Pietrzak
- Faculty of Chemistry, Łódź University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | - Min-Chul Chung
- Department of Chemistry, Syracuse University, Syracuse, New York 13244, United States
| | - Michael B. Sponsler
- Department of Chemistry, Syracuse University, Syracuse, New York 13244, United States
| | - Piotr Kaszyński
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-001 Łódź, Poland
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
- Faculty of Chemistry, University of Łódź, Tamka 12, 91-403 Łódź, Poland
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