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de Aguiar SRMM, Stöger B, Pittenauer E, Allmaier G, Veiros LF, Kirchner K. Structural diversity of halocarbonyl molybdenum and tungsten PNP pincer complexes through ligand modifications. Dalton Trans 2016; 45:13834-45. [PMID: 27513832 PMCID: PMC5048400 DOI: 10.1039/c6dt02251k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/18/2016] [Indexed: 11/21/2022]
Abstract
This work presents a comparative study of a series of halocarbonyl Mo(ii) and W(ii) complexes of the types [M(PNP)(CO)3X]X and [M(PNP)(CO)2X2] (M = Mo, W; X = I, Br), featuring PNP pincer ligands based on a 2,6-diaminopyridine scaffold. The complexes were prepared and fully characterized. The syntheses of these complexes were accomplished by treatment of [M(PNP)(CO)3] with stoichiometric amounts of I2 and Br2, respectively. The modification of the 2,6-diaminopyridine scaffold by introducing NMe and NPh instead of NH spacers with concomitant modification of the phosphine moieties changed the steric and electronic properties of the PNP ligand significantly. While in the case of NH linkers exclusively cationic seven-coordinate complexes of the type [M(PNP)(CO)3X](+) were obtained with NMe and NPh spacers neutral seven-coordinate complexes of the type [M(PNP)(CO)2X2] were afforded. In the case of the latter, when the reaction is performed in the presence of CO also [M(PNP)(CO)3X](+) complexes are formed which slowly lose CO to give [M(PNP)(CO)2X2]. The halocarbonyl tungsten chemistry parallels that of molybdenum. The only exception is molybdenum in conjunction with the PNP(Me)-iPr ligand, where the coordinatively unsaturated complex [Mo(PNP(Me)-iPr)(CO)X2] is formed. DFT mechanistic studies reveal that the seven-coordinate complexes should be the thermodynamic as well as the kinetic products. Since [Mo(PNP(Me)-iPr)(CO)X2] is the observed product it suggests that the reaction follows an alternative path. Structures of representative complexes were determined by X-ray single crystal analyses.
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Affiliation(s)
- Sara R. M. M. de Aguiar
- Institute of Applied Synthetic Chemistry , Vienna University of Technology , Getreidemarkt 9 , A-1060 Vienna , Austria .
| | - Berthold Stöger
- Institute of Chemical Technologies and Analytics , Vienna University of Technology , Getreidemarkt 9 , A-1060 Vienna , Austria
| | - Ernst Pittenauer
- Institute of Chemical Technologies and Analytics , Vienna University of Technology , Getreidemarkt 9 , A-1060 Vienna , Austria
| | - Günter Allmaier
- Institute of Chemical Technologies and Analytics , Vienna University of Technology , Getreidemarkt 9 , A-1060 Vienna , Austria
| | - Luis F. Veiros
- Centro de Química Estrutural , Instituto Superior Técnico , Universidade de Lisboa , Av. Rovisco Pais No. 1 , 1049-001 Lisboa , Portugal
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry , Vienna University of Technology , Getreidemarkt 9 , A-1060 Vienna , Austria .
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Castro-Rodrigo R, Chakraborty S, Munjanja L, Brennessel WW, Jones WD. Synthesis, Characterization, and Reactivities of Molybdenum and Tungsten PONOP Pincer Complexes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00461] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ruth Castro-Rodrigo
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Sumit Chakraborty
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Lloyd Munjanja
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William W. Brennessel
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William D. Jones
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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de Aguiar SRMM, Stöger B, Pittenauer E, Allmaier G, Veiros LF, Kirchner K. Arene C–H Bond Coordination versus C–H Bond Cleavage in Low-Valent Group 6 Carbonyl Pincer Complexes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Luis F. Veiros
- Centro
de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais No. 1, 1049-001 Lisboa, Portugal
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Labios LA, Heiden ZM, Mock MT. Electronic and Steric Influences of Pendant Amine Groups on the Protonation of Molybdenum Bis(dinitrogen) Complexes. Inorg Chem 2015; 54:4409-22. [PMID: 25871448 DOI: 10.1021/acs.inorgchem.5b00209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of a series of P(Et)P(NRR(')) (P(Et)P(NRR(')) = Et2PCH2CH2P(CH2NRR')2, R = H, R' = Ph or 2,4-difluorophenyl; R = R' = Ph or (i)Pr) diphosphine ligands containing mono- and disubstituted pendant amine groups and the preparation of their corresponding molybdenum bis(dinitrogen) complexes trans-Mo(N2)2(PMePh2)2(P(Et)P(NRR('))) is described. In situ IR and multinuclear NMR spectroscopic studies monitoring the stepwise addition of triflic acid (HOTf) to trans-Mo(N2)2(PMePh2)2(P(Et)P(NRR('))) complexes in tetrahydrofuran at -40 °C show that the electronic and steric properties of the R and R' groups of the pendant amines influence whether the complexes are protonated at Mo, a pendant amine, a coordinated N2 ligand, or a combination of these sites. For example, complexes containing monoaryl-substituted pendant amines are protonated at Mo and the pendant amine site to generate mono- and dicationic Mo-H species. Protonation of the complex containing less basic diphenyl-substituted pendant amines exclusively generates a monocationic hydrazido (Mo(NNH2)) product, indicating preferential protonation of an N2 ligand. Addition of HOTf to the complex featuring more basic diisopropyl amines primarily produces a monocationic product protonated at a pendant amine site, as well as a trace amount of dicationic Mo(NNH2) product that is additionally protonated at a pendant amine site. In addition, trans-Mo(N2)2(PMePh2)2(depe) (depe = Et2PCH2CH2PEt2) was synthesized to serve as a counterpart lacking pendant amines. Treatment of this complex with HOTf generated a monocationic Mo(NNH2) product. Protonolysis experiments conducted on several complexes in this study afforded trace amounts of NH4(+). Computational analysis of trans-Mo(N2)2(PMePh2)2(P(Et)P(NRR('))) complexes provides further insight into the proton affinity values of the metal center, N2 ligand, and pendant amine sites to rationalize differences in their reactivity profiles.
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Affiliation(s)
- Liezel A Labios
- ‡Center for Molecular Electrocatalysis, Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Zachariah M Heiden
- †Department of Chemistry, Washington State University, Pullman, Washington 99164, United States
| | - Michael T Mock
- ‡Center for Molecular Electrocatalysis, Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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Villafañe F. Dynamic behavior in solution of seven-coordinated transition metal complexes. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Öztopcu Ö, Holzhacker C, Puchberger M, Weil M, Mereiter K, Veiros LF, Kirchner K. Synthesis and Characterization of Hydrido Carbonyl Molybdenum and Tungsten PNP Pincer Complexes. Organometallics 2013; 32:3042-3052. [PMID: 23794778 PMCID: PMC3688336 DOI: 10.1021/om400254k] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Indexed: 11/28/2022]
Abstract
In the present study the Mo(0) and W(0) complexes [M(PNP)(CO)3] as well as seven-coordinate cationic hydridocarbonyl Mo(II) and W(II) complexes of the type [M(PNP)(CO)3H]+, featuring PNP pincer ligands based on 2,6-diaminopyridine, have been prepared and fully characterized. The synthesis of Mo(0) complexes [Mo(PNP)(CO)3] was accomplished by treatment of [Mo(CO)3(CH3CN)3] with the respective PNP ligands. The analogous W(0) complexes were prepared by reduction of the bromocarbonyl complexes [W(PNP)(CO)3Br]+ with NaHg. These intermediates were obtained from the known dinuclear complex [W(CO)4(μ-Br)Br]2, prepared in situ from W(CO)6 and stoichiometric amounts of Br2. Addition of HBF4 to [M(PNP)(CO)3] resulted in clean protonation at the molybdenum and tungsten centers to generate the Mo(II) and W(II) hydride complexes [M(PNP)(CO)3H]+. The protonation is fully reversible, and upon addition of NEt3 as base the Mo(0) and W(0) complexes [M(PNP)(CO)3] are regenerated quantitatively. All heptacoordinate complexes exhibit fluxional behavior in solution. The mechanism of the dynamic process of the hydrido carbonyl complexes was investigated by means of DFT calculations, revealing that it occurs in a single step. The structures of representative complexes were determined by X-ray single-crystal analyses.
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Affiliation(s)
- Özgür Öztopcu
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Christian Holzhacker
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Michael Puchberger
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Matthias Weil
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Kurt Mereiter
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F. Veiros
- Centro de Química Estrutural, Instituto
Superior Técnico, Universidade Técnica
de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisboa,
Portugal
| | - Karl Kirchner
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
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Marchetti F, Pampaloni G, Zacchini S. The reactivity of molybdenum pentachloride with ethers: routes to the synthesis of MoIVCl4 adducts, Mo(v) chlorido-alkoxides and Mo(v) oxydo-chlorides. Dalton Trans 2013; 42:15226-34. [DOI: 10.1039/c3dt51797g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Structural diversity in phosphoramidate’s chemistry: Syntheses, spectroscopic and X-ray crystallography studies. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.10.057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Mezei G, Zaleski CM, Pecoraro VL. Structural and Functional Evolution of Metallacrowns. Chem Rev 2007; 107:4933-5003. [PMID: 17999555 DOI: 10.1021/cr078200h] [Citation(s) in RCA: 433] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gellert Mezei
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
| | - Curtis M. Zaleski
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
| | - Vincent L. Pecoraro
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
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Kannan S, Rajalakshmi N, Chetty K, Venugopal V, Drew M. Complexes of the uranyl ion with bis(diphenylphosphino)methane dioxide. Polyhedron 2004. [DOI: 10.1016/j.poly.2004.03.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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