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Palluccio TD, Cai X, Majumdar S, Serafim LF, Tomson NC, Wieghardt K, Cazin CSJ, Nolan SP, Rybak-Akimova EV, Fernández-González MÁ, Temprado M, Captain B, Hoff CD. Ligand-Directed Reactivity in Dioxygen and Water Binding to cis-[Pd(NHC) 2(η 2-O 2)]. J Am Chem Soc 2018; 140:264-276. [PMID: 29172489 DOI: 10.1021/jacs.7b09905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Reaction of [Pd(IPr)2] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and O2 leads to the surprising discovery that at low temperature the initial reaction product is a highly labile peroxide complex cis-[Pd(IPr)2(η2-O2)]. At temperatures ≳ -40 °C, cis-[Pd(IPr)2(η2-O2)] adds a second O2 to form trans-[Pd(IPr)2(η1-O2)2]. Squid magnetometry and EPR studies yield data that are consistent with a singlet diradical ground state with a thermally accessible triplet state for this unique bis-superoxide complex. In addition to reaction with O2, cis-[Pd(IPr)2(η2-O2)] reacts at low temperature with H2O in methanol/ether solution to form trans-[Pd(IPr)2(OH)(OOH)]. The crystal structure of trans-[Pd(IPr)2(OOH)(OH)] is reported. Neither reaction with O2 nor reaction with H2O occurs under comparable conditions for cis-[Pd(IMes)2(η2-O2)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene). The increased reactivity of cis-[Pd(IPr)2(η2-O2)] is attributed to the enthalpy of binding of O2 to [Pd(IPr)2] (-14.5 ± 1.0 kcal/mol) that is approximately one-half that of [Pd(IMes)2] (-27.9 ± 1.5 kcal/mol). Computational studies identify the cause as interligand repulsion forcing a wider C-Pd-C angle and tilting of the NHC plane in cis-[Pd(IPr)2(η2-O2)]. Arene-arene interactions are more favorable and serve to further stabilize cis-[Pd(IMes)2(η2-O2)]. Inclusion of dispersion effects in DFT calculations leads to improved agreement between experimental and computational enthalpies of O2 binding. A complete reaction diagram is constructed for formation of trans-[Pd(IPr)2(η1-O2)2] and leads to the conclusion that kinetic factors inhibit formation of trans-[Pd(IMes)2(η1-O2)2] at the low temperatures at which it is thermodynamically favored. Failure to detect the predicted T-shaped intermediate trans-[Pd(NHC)2(η1-O2)] for either NHC = IMes or IPr is attributed to dynamic effects. A partial potential energy diagram for initial binding of O2 is constructed. A range of low-energy pathways at different angles of approach are present and blur the distinction between pure "side-on" or "end-on" trajectories for oxygen binding.
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Affiliation(s)
- Taryn D Palluccio
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Xiaochen Cai
- Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States
| | - Subhojit Majumdar
- Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States
| | - Leonardo F Serafim
- Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States
| | - Neil C Tomson
- Max-Planck Institute for Chemical Energy Conversion , Mülheim an der Ruhr, Germany.,Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Karl Wieghardt
- Max-Planck Institute for Chemical Energy Conversion , Mülheim an der Ruhr, Germany
| | - Catherine S J Cazin
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University , Campus Sterre, Building S-3, Krijgslaan 281, Ghent 9000, Belgium
| | - Steven P Nolan
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University , Campus Sterre, Building S-3, Krijgslaan 281, Ghent 9000, Belgium
| | - Elena V Rybak-Akimova
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Miguel Ángel Fernández-González
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Universidad de Alcalá , Madrid 28871, Spain
| | - Manuel Temprado
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Universidad de Alcalá , Madrid 28871, Spain
| | - Burjor Captain
- Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States
| | - Carl D Hoff
- Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States
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Walli A, Dechert S, Bauer M, Demeshko S, Meyer F. BOX Ligands in Biomimetic Copper-Mediated Dioxygen Activation: A Hemocyanin Model. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402378] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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3
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Cozzolino AF, Tofan D, Cummins CC, Temprado M, Palluccio TD, Rybak-Akimova EV, Majumdar S, Cai X, Captain B, Hoff CD. Two-Step Binding of O2 to a Vanadium(III) Trisanilide Complex To Form a Non-Vanadyl Vanadium(V) Peroxo Complex. J Am Chem Soc 2012; 134:18249-52. [DOI: 10.1021/ja309621h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anthony F. Cozzolino
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts
Avenue, Cambridge, Massachusetts 02139, United States
| | - Daniel Tofan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts
Avenue, Cambridge, Massachusetts 02139, United States
| | - Christopher C. Cummins
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts
Avenue, Cambridge, Massachusetts 02139, United States
| | - Manuel Temprado
- Department of Physical Chemistry, Universidad de Alcalá, Ctra. Madrid-Barcelona
Km. 33,600, Madrid 28871, Spain
| | - Taryn D. Palluccio
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts
02155, United States
| | - Elena V. Rybak-Akimova
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts
02155, United States
| | - Subhojit Majumdar
- Department
of Chemistry, University of Miami, 1301
Memorial Drive, Coral Gables,
Florida 33021, United States
| | - Xiaochen Cai
- Department
of Chemistry, University of Miami, 1301
Memorial Drive, Coral Gables,
Florida 33021, United States
| | - Burjor Captain
- Department
of Chemistry, University of Miami, 1301
Memorial Drive, Coral Gables,
Florida 33021, United States
| | - Carl D. Hoff
- Department
of Chemistry, University of Miami, 1301
Memorial Drive, Coral Gables,
Florida 33021, United States
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Marzouk A, Danset D, Zhou MF, Gong Y, Alikhani ME, Manceron L. Vibrational spectrum and structure of CoO6: a model compound for molecular oxygen reversible binding on cobalt oxides and salts; a combined IR matrix isolation and theoretical study. J Phys Chem A 2011; 115:9014-21. [PMID: 21721549 DOI: 10.1021/jp203943x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The formation and structure of a novel species, a disuperoxo-cobalt dioxide complex (CoO(6)), has been investigated using matrix isolation in solid neon and argon, coupled to infrared spectroscopy and by quantum chemical methods. It is found that CoO(6) can be formed by successive complexation of cobalt dioxide by molecular oxygen without activation energy by diffusion of ground state O(2) molecules at 9K in the dark. The IR data on one combination and seven fundamentals, isotopic effects, and quantum chemical calculations are both consistent with an asymmetrical structure with two slightly nonequivalent oxygen ligands complexing a cobalt dioxide subunit. Evidence for other, metastable states is also presented, but the data are not complete. The electronic structure and formation pathway of this unique, formally +VI oxidation state, complex has been investigated using several functionals of current DFT within the broken-symmetry unrestricted formalism. It has been shown that the M06L pure local functional well reproduce the experimental observations. The ground electronic state is predicted to be an open shell (2)A'' doublet with the quartet states above by more than 9 kcal/mol and the sextet lying even higher in energy. The ground state has a strong and complex multireference character that hinders the use of more precise multireference approaches and requires caution in the methodology to be used. The geometrical, energetic, and vibrational properties have been computed.
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Affiliation(s)
- Asma Marzouk
- UPMC Univ. Paris 06, UMR 7075, Laboratoire de Dynamique, Interactions et Réactivité (LADIR), F-75005, Paris, France
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Korendovych IV, Roesner RA, Rybak-Akimova EV. Molecular Recognition of Neutral and Charged Guests using Metallomacrocyclic Hosts. ADVANCES IN INORGANIC CHEMISTRY 2006. [DOI: 10.1016/s0898-8838(06)59004-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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6
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Aboelella NW, Kryatov SV, Gherman BF, Brennessel WW, Young VG, Sarangi R, Rybak-Akimova EV, Hodgson KO, Hedman B, Solomon EI, Cramer CJ, Tolman WB. Dioxygen Activation at a Single Copper Site: Structure, Bonding, and Mechanism of Formation of 1:1 Cu−O2 Adducts. J Am Chem Soc 2004; 126:16896-911. [PMID: 15612729 DOI: 10.1021/ja045678j] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To evaluate the fundamental process of O(2) activation at a single copper site that occurs in biological and catalytic systems, a detailed study of O(2) binding to Cu(I) complexes of beta-diketiminate ligands L (L(1) = backbone Me; L(2) = backbone tBu) by X-ray crystallography, X-ray absorption spectroscopy (XAS), cryogenic stopped-flow kinetics, and theoretical calculations was performed. Using synchrotron radiation, an X-ray diffraction data set for L(2)CuO(2) was acquired, which led to structural parameters in close agreement to theoretical predictions. Significant Cu(III)-peroxo character for the complex was corroborated by XAS. On the basis of stopped-flow kinetics data and theoretical calculations for the oxygenation of L(1)Cu(RCN) (R = alkyl, aryl) in THF and THF/RCN mixtures between 193 and 233 K, a dual pathway mechanism is proposed involving (a) rate-determining solvolysis of RCN by THF followed by rapid oxygenation of L(1)Cu(THF) and (b) direct, bimolecular oxygenation of L(1)Cu(RCN) via an associative process.
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Affiliation(s)
- Nermeen W Aboelella
- Department of Chemistry, Center for Metals in Biocatalysis, and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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Cherry JP, Johnson AR, Baraldo LM, Tsai YC, Cummins CC, Kryatov SV, Rybak-Akimova EV, Capps KB, Hoff CD, Haar CM, Nolan SP. On the origin of selective nitrous oxide N-N bond cleavage by three-coordinate molybdenum(III) complexes. J Am Chem Soc 2001; 123:7271-86. [PMID: 11472154 DOI: 10.1021/ja0031063] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reaction of Mo(N[R]Ar)(3) (R = (t)Bu or C(CD(3))(2)CH(3)) with N(2)O gives rise exclusively to a 1:1 mixture of nitride NMo(N[R]Ar)(3) and nitrosyl ONMo(N[R]Ar)(3), rather than the known oxo complex OMo(N[R]Ar)(3) and dinitrogen. Solution calorimetry measurements were used to determine the heat of reaction of Mo(N[R]Ar)(3) with N(2)O and, independently, the heat of reaction of Mo(N[R]Ar)(3) with NO. Derived from the latter measurements is an estimate (155.3 +/- 3.3 kcal.mol(-1)) of the molybdenum-nitrogen bond dissociation enthalpy for the terminal nitrido complex, NMo(N[R]Ar)(3). Comparison of the new calorimetry data with those obtained previously for oxo transfer to Mo(N[R]Ar)(3) shows that the nitrous oxide N-N bond cleavage reaction is under kinetic control. Stopped-flow kinetic measurements revealed the reaction to be first order in both Mo(N[R]Ar)(3) and N(2)O, consistent with a mechanism featuring post-rate-determining dinuclear N-N bond scission, but also consistent with cleavage of the N-N bond at a single metal center in a mechanism requiring the intermediacy of nitric oxide. The new 2-adamantyl-substituted molybdenum complex Mo(N[2-Ad]Ar)(3) was synthesized and found also to split N(2)O, resulting in a 1:1 mixture of nitrosyl and nitride products; the reaction exhibited first-order kinetics and was found to be ca. 6 times slower than that for the tert-butyl-substituted derivative. Discussed in conjunction with studies of the 2-adamantyl derivative Mo(N[2-Ad]Ar)(3) is the role of ligand-imposed steric constraints on small-molecule, e.g. N(2) and N(2)O, activation reactivity. Bradley's chromium complex Cr(N(i)Pr(2))(3) was found to be competitive with Mo(N[R]Ar)(3) for NO binding, while on its own exhibiting no reaction with N(2)O. Competition experiments permitted determination of ratios of second-order rate constants for NO binding by the two molybdenum complexes and the chromium complex. Analysis of the product mixtures resulting from carrying out the N(2)O cleavage reactions with Cr(N(i)Pr(2))(3) present as an in situ NO scavenger rules out as dominant any mechanism involving the intermediacy of NO. Simplest and consistent with all the available data is a post-rate-determining bimetallic N-N scission process. Kinetic funneling of the reaction as indicated is taken to be governed by the properties of nitrous oxide as a ligand, coupled with the azophilic nature of three-coordinate molybdenum(III) complexes.
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Affiliation(s)
- J P Cherry
- Contribution from the Departments of Chemistry, Room 2-227, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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Van Doorslaer S, Schweiger A, Kräutler B. A Continuous Wave and Pulse EPR and ENDOR Investigation of Oxygenated Co(II) Corrin Complexes. J Phys Chem B 2001. [DOI: 10.1021/jp004270f] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabine Van Doorslaer
- Physical Chemistry Laboratory, Swiss Federal Institute of Technology, 8092 Zurich, Switzerland, and Institute for Organic Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Arthur Schweiger
- Physical Chemistry Laboratory, Swiss Federal Institute of Technology, 8092 Zurich, Switzerland, and Institute for Organic Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Bernhard Kräutler
- Physical Chemistry Laboratory, Swiss Federal Institute of Technology, 8092 Zurich, Switzerland, and Institute for Organic Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
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Rybak-Akimova, EV. Macrocyclic Metallocomplexes in Multipoint Molecular Recognition of Neutral and Anionic Guests. REV INORG CHEM 2001. [DOI: 10.1515/revic.2001.21.3-4.207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Rybak-Akimova EV, Kuczera K. Ligand binding inside the cavities of lacunar and saddle-shaped cyclidene complexes: molecular mechanics and molecular dynamics studies. Inorg Chem 2000; 39:2462-72. [PMID: 11196997 DOI: 10.1021/ic990738l] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cobalt(II) complexes with tetradentate macrocyclic cyclidene ligands are known to coordinate one additional axial base molecule, leaving the sixth vacant coordination site at the metal ion available for small ligand (e.g., O2) binding. Molecular mechanics and molecular dynamics simulations provide a microscopic view of 1-methylimidazole (MeIm) binding within the cavities of several lacunar (bridged) and saddle-shaped (unbridged) cyclidenes and uncover the roles of the bridges and the walls of the clefts in steric protection of the cobalt(II) coordination site. Short bridges (C3 and C6) prevent inside-the-cavity MeIm binding because of severe ligand distortions leading to high-energy penalties (58 and 25 kcal/mol, respectively), while long bridges (C8 and C12) flip away from the MeIm binding site, allowing for penalty-free MeIm inclusion. In the unbridged saddle-shaped complex, there is no energy difference between inside- and outside-the-cavity MeIm binding. The preferential existence of the coordinatively unsaturated, five-coordinate species Co(unbrCyc)(MeIm)2+ should therefore be explained by electronic, rather than steric, factors. Molecular dynamics and free energy simulations reveal the presence of a weak (ca. 4 kcal/mol in the gas phase and ca. 2 kcal/mol in methanol solution) noncovalent MeIm binding site at the entrance of the cleft of cobalt(II) unbridged cyclidene, at a distance of about 4 A from the metal ion. The macrocycle geometry remains undistorted at such large Co-N(MeIm) separations, while the cavity opens up by 0.9 A upon covalent MeIm binding (Co-N(MeIm) distance of 2 A). An increase in macrocycle strain energy upon MeIm inclusion is compensated by favorable nonbonded interactions between the incoming base and the walls of the unbridged cyclidene.
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Affiliation(s)
- E V Rybak-Akimova
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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