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Ault BS. Probing the Structure of the 1:1 Hydrogen-Bonded Complexes of Metallocenes with HCl. J Phys Chem A 2024; 128:1233-1240. [PMID: 38350638 DOI: 10.1021/acs.jpca.3c07451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Matrix isolation infrared spectroscopy combined with density functional calculations has been used to form, isolate, and characterize the 1:1 hydrogen-bonded complexes of HCl with ferrocene and ruthenocene. Two unique structures were calculated for each complex, analogous to the two binding sites proposed for the attachment of proton to these metallocenes. The spectra, combined with calculated shifts of the H-Cl stretching mode, support the formation of a complex with the HCl hydrogen bonding to one of the cyclopentadienyl rings, exo to the plane of the ring. Evidence also was obtained for a second structure with the hydrogen of the HCl subunit directed toward the Fe or Ru center between the two cyclopentadienyl rings. This structure is similar to the proposed metal-bound proton structure based on earlier mass spectrometric and computational studies. Importantly, these results were supported by parallel experiments with DCl and the two metallocenes.
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Affiliation(s)
- Bruce S Ault
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45219, United States
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2
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Pavlov J, Zheng Z, Douce D, Bajic S, Attygalle AB. Helium-Plasma-Ionization Mass Spectrometry of Metallocenes and Their Derivatives. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:548-559. [PMID: 33395292 DOI: 10.1021/jasms.0c00387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ferrocene and its derivatives and nickelocene undergo facile ionization when exposed directly to the ionizing plasma of a helium-plasma ionization (HePI) source. Mass spectra recorded from such samples under ambient positive-ion-generating conditions show intense peaks for the respective molecular ions [M+•] and protonated species [(M + H)+]. The protonation process occurs most efficiently when traces of water are present in the heated nitrogen used as the "heating gas." In fact, the relative population of the two categories of ions generated in this way can be manipulated by regulating the heating-gas flow. Moreover, rapid and highly efficient gas-phase hydrogen-deuterium exchange (HDX) reactions can be performed in the ion source by passing the heating gas through a vial with D2O before it reaches the HePI source. Moreover, the ionized species generated in this way can be subjected to in-source CID fragmentation in the QDa-HePI source very efficiently by varying the sampling-cone voltage. By this procedure, ions generated from ferrocene and nickelocene could be stripped so far as to ultimately generate the bare-metal cation. Other typical fragment-ions produced from protonated metallocenes included the M(cp)1+ ions (M = Fe or Ni), by elimination of a cyclopentadiene molecule, or the molecular cation, by loss of a H• radical. Moreover, H/D exchanges and subsequent tandem mass spectrometric analysis indicated that the central metal core participates in the initial protonation process of ferrocene under HePI conditions. However, in compounds such as ferrocene carboxaldehyde and ferrocene boronic acid, the protonation takes place at the peripheral functional group.
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Affiliation(s)
- Julius Pavlov
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Zhaoyu Zheng
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - David Douce
- Waters Corporation, Wilmslow, Cheshire SK9 4AX, U.K
| | - Steve Bajic
- Waters Corporation, Wilmslow, Cheshire SK9 4AX, U.K
| | - Athula B Attygalle
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
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3
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Chamkin AA, Krivykh VV, Nikitin OM, Kreindlin AZ, Shteltser NA, Dolgushin FM, Artyushin OI, Ikonnikov NS, Borisov YA, Belousov YA, Ustynyuk NA. Direct Phosphination of Ferrocenium Ion with Tertiary Phosphines by the Mechanism of Oxidative Nucleophilic Substitution. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800961] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Aleksandr A. Chamkin
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Vasily V. Krivykh
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Oleg M. Nikitin
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Arkady Z. Kreindlin
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Nikolai A. Shteltser
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Fedor M. Dolgushin
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Oleg I. Artyushin
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Nikolai S. Ikonnikov
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Yuri A. Borisov
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Yuri A. Belousov
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
| | - Nikolai A. Ustynyuk
- Russian Academy of Sciences A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) 119991, GSP‐1 Moscow, V‐334, Vavilova St. 28, INEOS Russia
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4
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Malischewski M, Seppelt K, Sutter J, Heinemann FW, Dittrich B, Meyer K. Protonation of Ferrocene: A Low-Temperature X-ray Diffraction Study of [Cp2
FeH](PF6
) Reveals an Iron-Bound Hydrido Ligand. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201704854] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Moritz Malischewski
- Freie Universität Berlin; Institut für Chemie und Biochemie, Anorganische Chemie; Fabeckstrasse 34-36 14195 Berlin Germany
| | - Konrad Seppelt
- Freie Universität Berlin; Institut für Chemie und Biochemie, Anorganische Chemie; Fabeckstrasse 34-36 14195 Berlin Germany
| | - Jörg Sutter
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
| | - Frank W. Heinemann
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
| | - Birger Dittrich
- Heinrich-Heine-Universität Düsseldorf; Anorganische Chemie und Strukturchemie; Universitätsstrasse 1 40225 Düsseldorf Germany
| | - Karsten Meyer
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
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5
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Malischewski M, Seppelt K, Sutter J, Heinemann FW, Dittrich B, Meyer K. Protonation of Ferrocene: A Low-Temperature X-ray Diffraction Study of [Cp2
FeH](PF6
) Reveals an Iron-Bound Hydrido Ligand. Angew Chem Int Ed Engl 2017; 56:13372-13376. [DOI: 10.1002/anie.201704854] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/18/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Moritz Malischewski
- Freie Universität Berlin; Institut für Chemie und Biochemie, Anorganische Chemie; Fabeckstrasse 34-36 14195 Berlin Germany
| | - Konrad Seppelt
- Freie Universität Berlin; Institut für Chemie und Biochemie, Anorganische Chemie; Fabeckstrasse 34-36 14195 Berlin Germany
| | - Jörg Sutter
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
| | - Frank W. Heinemann
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
| | - Birger Dittrich
- Heinrich-Heine-Universität Düsseldorf; Anorganische Chemie und Strukturchemie; Universitätsstrasse 1 40225 Düsseldorf Germany
| | - Karsten Meyer
- Friedrich-Alexander-Universität Erlangen-Nürnberg; Department für Chemie und Pharmazie, Anorganische Chemie; Egerlandstrasse 1 91058 Erlangen Germany
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6
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Pracht P, Bauer CA, Grimme S. Automated and efficient quantum chemical determination and energetic ranking of molecular protonation sites. J Comput Chem 2017; 38:2618-2631. [DOI: 10.1002/jcc.24922] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/27/2017] [Accepted: 08/01/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Philipp Pracht
- Mulliken Center for Theoretical Chemistry, Institute of Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4; 53115 Bonn Germany
| | - Christoph Alexander Bauer
- Mulliken Center for Theoretical Chemistry, Institute of Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4; 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute of Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4; 53115 Bonn Germany
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7
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Sharma N, Ajay JK, Venkatasubbaiah K, Lourderaj U. Mechanisms and dynamics of protonation and lithiation of ferrocene. Phys Chem Chem Phys 2015; 17:22204-9. [DOI: 10.1039/c5cp03735b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio direct dynamics studies reveal that protonation and lithiation of ferrocene follow in general an exo mechanism.
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Affiliation(s)
- Nishant Sharma
- School of Chemical Sciences
- National Institute of Science Education and Research
- Bhubaneswar
- India
| | - Jayanth K. Ajay
- School of Chemical Sciences
- National Institute of Science Education and Research
- Bhubaneswar
- India
| | | | - Upakarasamy Lourderaj
- School of Chemical Sciences
- National Institute of Science Education and Research
- Bhubaneswar
- India
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8
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Sadhukhan N, Sarkar M, Ghatak T, Rahaman SMW, Barbour LJ, Bera JK. Reactions of acids with naphthyridine-functionalized ferrocenes: protonation and metal extrusion. Inorg Chem 2013; 52:1432-42. [PMID: 23347083 DOI: 10.1021/ic302155e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Reaction of 1,8-naphthyrid-2-yl-ferrocene (FcNP) with a variety of acids affords protonated salts at first, whereas longer reaction time leads to partial demetalation of FcNP resulting in a series of Fe complexes. The corresponding salts [FcNP·H][X] (X = BF(4) or CF(3)SO(3) (1)) are isolated for HBF(4) and CF(3)SO(3)H. Reaction of FcNP with equimolar amount of CF(3)CO(2)H for 12 h affords a neutral complex [Fe(FcNP)(2)(O(2)CCF(3))(2)(OH(2))(2)] (2). Use of excess acid gave a trinuclear Fe(II) complex [Fe(3)(H(2)O)(2)(O(2)CCF(3))(8)(FcNP·H)(2)] (3). Three linear iron atoms are held together by four bridging trifluoroacetates and two aqua ligands in a symmetric fashion. Reaction with ethereal solution of HCl afforded [(FcNP·H)(3)(Cl)][FeCl(4)](2) (4) irrespective of the amount of the acid used. Even the picric acid (HPic) led to metal extrusion giving rise to [Fe(2)(Cl)(2)(FcNP)(2)(Pic)(2)] (5) when crystallized from dichloromethane. Metal extrusion was also observed for CF(3)SO(3)H, but an analytically pure compound could not be isolated. The demetalation reaction proceeds with an initial proton attack to the distal nitrogen of the NP unit. Subsequently, coordination of the conjugate base to the electrophilic Fe facilitates the release of Cp rings from metal. The conjugate base plays an important role in the demetalation process and favors the isolation of the Fe complex as well. The 1,1'-bis(1,8-naphthyrid-2-yl)ferrocene (FcNP(2)) does not undergo demetalation under identical conditions. Two NP units share one positive charge causing the Fe-Cp bonds weakened to an extent that is not sufficient for demetalation. X-ray structure of the monoprotonated FcNP(2) reveals a discrete dimer [(FcNP(2)·H)](2)[OTf](2) (6) supported by two N-H···N hydrogen bonds. Crystal packing and dispersive forces associated with intra- and intermolecular π-π stacking interactions (NP···NP and Cp···NP) allow the formation of the dimer in the solid-state. The protonation and demetalation reactions of FcNP and FcNP(2) with a variety of acids are reported.
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Affiliation(s)
- Nabanita Sadhukhan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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9
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Gryaznova TP, Katsyuba SA, Milyukov VA, Sinyashin OG. DFT study of substitution effect on the geometry, IR spectra, spin state and energetic stability of the ferrocenes and their pentaphospholyl analogues. J Organomet Chem 2010. [DOI: 10.1016/j.jorganchem.2010.08.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Sorkin A, Truhlar DG, Amin EA. Energies, Geometries, and Charge Distributions of Zn Molecules, Clusters, and Biocenters from Coupled Cluster, Density Functional, and Neglect of Diatomic Differential Overlap Models. J Chem Theory Comput 2009; 5:1254-65. [PMID: 26609716 DOI: 10.1021/ct900038m] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present benchmark databases of Zn-ligand bond distances, bond angles, dipole moments, and bond dissociation energies for Zn-containing small molecules and Zn coordination compounds with H, CH3, C2H5, NH3, O, OH, H2O, F, Cl, S, and SCH3 ligands. The test set also includes clusters with Zn-Zn bonds. In addition, we calculated dipole moments and binding energies for Zn centers in coordination environments taken from zinc metalloenzyme X-ray structures, representing both structural and catalytic zinc centers. The benchmark values are based on relativistic-core coupled cluster calculations. These benchmark calculations are used to test the predictions of four density functionals, namely B3LYP and the more recently developed M05-2X, M06, and M06-2X levels of theory, and six semiempirical methods, including neglect of diatomic differential overlap (NDDO) calculations incorporating the new PM3 parameter set for Zn called ZnB, developed by Brothers and co-workers, and the recent PM6 parametrization of Stewart. We found that the best DFT method to reproduce dipole moments and dissociation energies of our Zn compound database is M05-2X, which is consistent with a previous study employing a much smaller and less diverse database and a much larger set of density functionals. Here we show that M05-2X geometries and single-point coupled cluster calculations with M05-2X geometries can also be used as benchmarks for larger compounds, where coupled cluster optimization is impractical, and in particular we use this strategy to extend the geometry, binding energy, and dipole moment databases to additional molecules, and we extend the tests involving crystal-site coordination compounds to two additional proteins. We find that the most predictive NDDO methods for our training set are PM3 and MNDO/d. Notably, we also find large errors in B3LYP for the coordination compounds based on experimental X-ray geometries.
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Affiliation(s)
- Anastassia Sorkin
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959, and Department of, Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota, 55455-0431
| | - Donald G Truhlar
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959, and Department of, Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota, 55455-0431
| | - Elizabeth A Amin
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959, and Department of, Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota, 55455-0431
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11
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Šarić A, Vrček V, Bühl M. Density Functional Study of Protonated Formylmetallocenes. Organometallics 2008. [DOI: 10.1021/om700916f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andela Šarić
- Faculty of Sciences, University of Zagreb, HR-10000, Zagreb, Croatia, Faculty of Pharmacy and Biochemistry, University of Zagreb, HR-10000, Zagreb, Croatia, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Valerije Vrček
- Faculty of Sciences, University of Zagreb, HR-10000, Zagreb, Croatia, Faculty of Pharmacy and Biochemistry, University of Zagreb, HR-10000, Zagreb, Croatia, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Michael Bühl
- Faculty of Sciences, University of Zagreb, HR-10000, Zagreb, Croatia, Faculty of Pharmacy and Biochemistry, University of Zagreb, HR-10000, Zagreb, Croatia, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
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12
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Jayasooriya UA, Grinter R, Hubbard PL, Aston GM, Stride JA, Hopkins GA, Camus L, Reid ID, Cottrell SP, Cox SFJ. Muon Implantation of Metallocenes: Ferrocene. Chemistry 2007; 13:2266-76. [PMID: 17163549 DOI: 10.1002/chem.200600853] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Muon Spin Relaxation and Avoided Level Crossing (ALC) measurements of ferrocene are reported. The main features observed are five high field resonances in the ALC spectrum at about 3.26, 2.44, 2.04, 1.19 and 1.17 T, for the low-temperature phase at 18 K. The high-temperature phase at 295 K shows that only the last feature shifted down to about 0.49 T and a muon spin relaxation peak at about 0.106 T which approaches zero field when reaching the phase transition temperature of 164 K. A model involving three muoniated radicals, two with muonium addition to the cyclopentadienyl ring and the other to the metal atom, is postulated to rationalise these observations. A theoretical treatment involving spin-orbit coupling is found to be required to understand the Fe-Mu adduct, where an interesting interplay between the ferrocene ring dynamics and the spin-orbit coupling of the unpaired electron is shown to be important. The limiting temperature above which the full effect of spin-orbit interaction is observable in the muSR spectra of ferrocene was estimated to be 584 K. Correlation time for the ring rotation dynamics of the Fe-Mu radical at this temperature is 3.2 ps. Estimated electron g values and the changes in zero-field splittings for this temperature range are also reported.
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Affiliation(s)
- Upali A Jayasooriya
- School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, UK.
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13
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Abstract
The ions formally corresponding to protonated heme [Fe(II)-hemeH](+) have been obtained by collision-induced dissociation from the electrospray ionization of microperoxidase (MP11) and their gas-phase chemistry has been studied by FTICR mass spectrometry. H/D-exchange reactions, used as a tool to gain information on the protonation sites in polyfunctional molecules, show that labile hydrogens pertain to the propionyl substituents at the periphery of the protoporphyrin IX. Several conceivable isomers for protonated heme have been evaluated by density functional theory. The most stable among the species investigated is the one corresponding to protonation at the beta carbon atom of a vinyl group, yielding a proton affinity (PA) value for [Fe(II)-heme] of 1220 kJ mol(-1). This high PA is consistent with the inertness of the hydrogen atoms at the protonation site towards H/D exchange with ND(3) and CD(3)CO(2)D. Peculiar features of this [Fe(II)-hemeH](+) isomer emerge by analysis of its electronic structure, showing that the vinyl group undergoing formal protonation has gained significant radical character due to electron transfer from the metal center. As a consequence, the iron atom acquires partial iron(III) character and none of the two formal descriptions [Fe(II)-hemeH(+)] and [Fe(III)-hemeH(.)](+) alone may adequately illustrate the protonated heme ion. In agreement with this description, the reactivity of protonated heme presents dual facets, resembling iron(III) in some aspects and iron(II) in others. On the one hand, protonated heme behaves like [Fe(III)-heme](+) ions in H/D-exchange reactions. On the other, it shows markedly decreased reactivity towards the addition of ligands with the notable exception of NO, in line with the high affinity shown by iron(II) complexes towards this molecule, NO, of key biological role.
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Affiliation(s)
- Barbara Chiavarino
- Dipartimento Studi di Chimica e Tecnologia delle Sostanze, Biologicamente Attive, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy
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14
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Abstract
The molecular structures of ferrocene in the eclipsed (equilibrium) and staggered (saddle-point) conformations have been determined by full geometry optimizations at the levels of second-order Møller-Plesset (MP2) theory, coupled-cluster singles-and-doubles (CCSD) theory, and CCSD theory with a perturbative triples correction [CCSD(T)] in a TZV2P+f basis set. Existing experimental results are reviewed. The agreement between the CCSD(T) results and experiment is in all cases excellent; the calculated structure parameters and the barrier to internal rotation of the ligand rings differ from the most accurate experimental values by less than two estimated standard deviations. The CCSD(T) calculations for single-configuration-dominated transition metal complexes such as ferrocene thus appear to have an accuracy comparable to that observed for molecules containing only first- and second-row atoms, and to be of a quality similar to that obtained experimentally. A comparison with previous DFT results indicates that the B3LYP model gives overall the best DFT results, with a deviation of around 2 pm for the metal-carbon distance and smaller errors for the cyclopentadienyl rings.
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Affiliation(s)
- Sonia Coriani
- Dipartimento di Scienze Chimiche, Università degli Studi di Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy.
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15
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Hyla-Kryspin I, Grimme S. Comprehensive Study of the Thermochemistry of First-Row Transition Metal Compounds by Spin Component Scaled MP2 and MP3 Methods. Organometallics 2004. [DOI: 10.1021/om049521b] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Isabella Hyla-Kryspin
- Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Stefan Grimme
- Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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16
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Ishimura K, Hada M, Nakatsuji H. Ionized and excited states of ferrocene: Symmetry adapted cluster–configuration–interaction study. J Chem Phys 2002. [DOI: 10.1063/1.1504709] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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McKee ML. Density functional study of the retrocyclization of norbornadiene and norbornene catalyzed by Fe(+). J Am Chem Soc 2001; 123:9426-35. [PMID: 11562226 DOI: 10.1021/ja011165q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the presence of Fe(+) catalyst, the retro Diels-Alder reaction of norbornadiene (NBD) is predicted to be stepwise with an activation barrier of 18.8 kcal/mol, which is 3.1 kcal/mol lower than the concerted retro reaction. For norbornene (NBN), the Fe(+)-catalyzed retro reaction is also calculated to be stepwise with an activation barrier of 24.9 kcal/mol, which is 8.5 kcal/mol lower than the uncatalyzed stepwise reaction but 3.8 kcal/mol higher than the concerted reaction. The intermediates from the NBD and NBN retro Diels-Alder reactions, C(5)H(6)FeC(2)H(2)(+) and C(5)H(6)FeC(2)H(4)(+), are predicted to have low activation barriers for ligand-to-ligand hydrogen transfers (through an iron-hydrido intermediate) to form CpFeC(2)H(3)(+) and CpFeC(2)H(5)(+) and, ultimately, vinyl- and ethyl-substituted cyclopentadiene-iron complexes, respectively. In contrast to FeC(2)H(2)(+) and FeC(2)H(4)(+), the lowest-energy pathways on the C(5)H(6)FeC(2)H(2)(+) and C(5)H(6)FeC(2)H(4)(+) potential energy surfaces involve only one multiplicity (quartet). The C(2)H(2) and C(2)H(4) complexes of CpFe(+) and C(5)H(6)Fe(+) are compared.
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Affiliation(s)
- M L McKee
- Department of Chemistry, Auburn University, Auburn, Alabama 36849, USA
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Irigoras A, Mercero JM, Silanes I, Ugalde JM. The ferrocene--lithium cation complex in the gas phase. J Am Chem Soc 2001; 123:5040-3. [PMID: 11457332 DOI: 10.1021/ja003103q] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stable isomers of the ferrocene--lithium cation gas-phase ion complex have been studied with the hybrid density functional theory. The method of calculation chosen has been tested checking its performance for the more studied protonated ferrocene species. Our calculations demonstrate that the procedure used is reliable. We have found two isomers of the ferrocene--lithium cation complex separated by a barrier of 25.6 kcal/mol. The most stable isomer of this complex has Li(+) on-top of one of the cyclopentadienyls, while in the least stable isomer Li(+) binds the central iron metal. The latter isomer has been characterized as a planetary system in the sense that Li(+) has one thermally accessible planar orbit around the central ferrocene moiety. Our calculations lead to a value of ferrocene's gas-phase lithium cation basicity of 37.4 kcal/mol for the on-top complex and 29.4 kcal/mol for the metal-bound complex.
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Affiliation(s)
- A Irigoras
- Kimika Fakultatea, Euskal Herriko Unibertsitatea, P. K. 1072, 20080 Donostia, Euskadi, Spain
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