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Karagiannis A, Neugebauer H, Lalancette RA, Grimme S, Hansen A, Prokopchuk DE. Pushing the Limits of Organometallic Redox Chemistry with an Isolable Mn(-I) Dianion. J Am Chem Soc 2024; 146:19279-19285. [PMID: 38976843 DOI: 10.1021/jacs.4c04561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
We report an incredibly reducing and redox-active Mn-I dianion, [Mn(CO)3(Ph2B(tBuNHC)2)]2- (NHC = N-heterocyclic carbene), furnished via 2e- reduction of the parent 16e- MnI complex with Na0 or K0. Cyclic voltammograms show a Mn0/-I redox couple at -3.13 V vs Fc+/0 in tetrahydrofuran (THF), -3.06 V in 1,2-dimethoxyethane, and -2.85 V in acetonitrile. The diamagnetic Mn-I dianion is stable in solution and solid-state at room temperature, tolerating a wide range of countercations ([M(2.2.2)crypt]+, [M(18-crown-6)]+, [nBu4N]+; M = Na, K). Countercation identity does not significantly alter 13C NMR spectral signatures with [nBu4N]+ and Na+, suggesting minimal ion pairing in solution. IR spectroscopy reveals a significant decrease in CO stretching frequencies from MnI to Mn-I (ca. 240 cm-1), consistent with a drastic increase in electron density at Mn. State-of-the-art DFT calculations are in excellent agreement with the observed IR spectral data. Moreover, the Mn-I dianion behaves as a chemical reductant, smoothly releasing 1e- or 2e- to regenerate the oxidized Mn0 or MnI species in solution. The reducing potential of [Mn(CO)3(Ph2B(tBuNHC)2)]2- surpasses the naphthalenide anion in THF (-3.09 V) and represents one of the strongest isolable chemical redox agents.
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Affiliation(s)
- Ageliki Karagiannis
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Hagen Neugebauer
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
- Mulliken Center for Theoretical Chemistry, Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn, Bonn 53115, Germany
| | - Roger A Lalancette
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn, Bonn 53115, Germany
| | - Andreas Hansen
- Mulliken Center for Theoretical Chemistry, Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn, Bonn 53115, Germany
| | - Demyan E Prokopchuk
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
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2
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Scherz F, Bauer M, Domenianni LI, Hoyer C, Schmidt J, Sarkar B, Vöhringer P, Krewald V. Ultrafast photogeneration of a metal-organic nitrene from 1,1'-diazidoferrocene. Chem Sci 2024; 15:6707-6715. [PMID: 38725494 PMCID: PMC11077559 DOI: 10.1039/d4sc00883a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 04/08/2024] [Indexed: 05/12/2024] Open
Abstract
Ferrocene and its derivatives have fascinated chemists for more than 70 years, not least due to the analogies with the properties of benzene. Despite these similarities, the obvious difference between benzene and ferrocene is the presence of an iron ion and hence the availability of d-orbitals for properties and reactivity. Phenylnitrene with its rich photochemistry can be considered an analogue of nitrenoferrocene. As with most organic and inorganic nitrenes, nitrenoferrocene can be obtained by irradiating the azide precursor. We study the photophysical and photochemical processes of dinitrogen release from 1,1'-diazidoferrocene to form 1-azido-1'-nitrenoferrocene with UV-pump-mid-IR-probe transient absorption spectroscopy and time-dependent density functional theory calculations including spin-orbit coupling. An intermediate with a bent azide moiety is identified that is pre-organised for dinitrogen release via a low-lying transition state. The photochemical decay paths on the singlet and triplet surfaces including the importance of spin-orbit coupling are discussed. We compare our findings with the processes discussed for photochemical dinitrogen activation and highlight implications for the photochemistry of azides more generally.
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Affiliation(s)
- Frederik Scherz
- Department of Chemistry, Theoretical Chemistry, TU Darmstadt Peter-Grünberg-Str. 4 64287 Darmstadt Germany
| | - Markus Bauer
- Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn Wegelerstraße 12 53115 Bonn Germany
| | - Luis I Domenianni
- Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn Wegelerstraße 12 53115 Bonn Germany
| | - Carolin Hoyer
- Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstraße 34-36 14195 Berlin Germany
| | - Jonas Schmidt
- Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn Wegelerstraße 12 53115 Bonn Germany
| | - Biprajit Sarkar
- Institute of Inorganic Chemistry, University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
- Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstraße 34-36 14195 Berlin Germany
| | - Peter Vöhringer
- Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn Wegelerstraße 12 53115 Bonn Germany
| | - Vera Krewald
- Department of Chemistry, Theoretical Chemistry, TU Darmstadt Peter-Grünberg-Str. 4 64287 Darmstadt Germany
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3
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Choi H, Yoo S, Song H, Lee E. IZCp and PZCp: Redox Non-innocent Cyclopentadienyl Ligands as Electron Reservoirs for Sandwich Complexes. Inorg Chem 2024; 63:6427-6434. [PMID: 38534011 DOI: 10.1021/acs.inorgchem.4c00259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
A long-sustained effort of systematic steric and electronic modification of cyclopentadienyl (Cp) ligands has enabled them to find wide-ranging, valuable applications. Herein, we present two novel Cp ligands: imidazolium- and pyrrolinium-substituted zwitterionic Cps (IZCp and PZCp), whose key utility is redox non-innocence─the ability to participate cooperatively with the metal center in redox reactions. Through the simple metalation of ZCps, the Cr(0) and Mo(0) half-sandwich complexes (IZCp)Cr(CO)3, (PZCp)Cr(CO)3, (IZCp)Mo(CO)3, and (PZCp)Mo(CO)3, respectively, as well as the Ru(II) sandwich complexes [(IZCp)RuCp]PF6 and [(PZCp)RuCp]PF6 were prepared. The sandwich complexes were fully characterized and showed by cyclic voltammetry reversible one-electron reduction at E1/2 potentials ranging from -1.7 to -2.7 V vs Fc/Fc+. These values are unusually low and have not been observed with other Cp ligands due to the instability of the reduced complexes. Density functional theory (DFT) calculations for the reduced sandwich derivatives with IZCp and PZCp showed their spin densities to be highly delocalized over their ZCp ligand moieties (70-90%). Electron paramagnetic resonance (EPR) analysis of the isolated K[(PZCp)Mo(CO)3] and (PZCp)RuCp also indicated a high degree of ligand-localized radical character. Thus, the IZCp and PZCp ligands act as electron reservoirs to sustain these sandwich complexes in highly reduced states. At the same time, the CO stretching frequencies of K[(PZCp)Mo(CO)3]: νCO 1871, 1748, and 1699 cm-1, rank the [PZCp]- ligand as the strongest electron-donating Cp ligand among the reported CpMo(CO)3 derivatives, whose νCO > 1746 cm-1. In addition, these redox non-innocent Cps were obtained in high yields and found to be practically air- and moisture-stable, unlike typical Cps.
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Affiliation(s)
- Hyeonjeong Choi
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Seunghyuk Yoo
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Hayoung Song
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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4
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Nagelski AL, Ozerov M, Fataftah MS, Krzystek J, Greer SM, Holland PL, Telser J. Electronic Structure of Three-Coordinate Fe II and Co II β-Diketiminate Complexes. Inorg Chem 2024; 63:4511-4526. [PMID: 38408452 DOI: 10.1021/acs.inorgchem.3c03388] [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
The β-diketiminate supporting group, [ArNCRCHCRNAr]-, stabilizes low coordination number complexes. Four such complexes, where R = tert-butyl, Ar = 2,6-diisopropylphenyl, are studied: (nacnactBu)ML, where M = FeII, CoII and L = Cl, CH3. These are denoted FeCl, FeCH3, CoCl, and CoCH3 and have been previously reported and structurally characterized. The two FeII complexes (S = 2) have also been previously characterized by Mössbauer spectroscopy, but only indirect assessment of the ligand-field splitting and zero-field splitting (zfs) parameters was available. Here, EPR spectroscopy is used, both conventional field-domain for the CoII complexes (with S = 3/2) and frequency-domain, far-infrared magnetic resonance spectroscopy (FIRMS) for all four complexes. The CoII complexes were also studied by magnetometry. These studies allow accurate determination of the zfs parameters. The two FeII complexes are similar with nearly axial zfs and large magnitude zfs given by D = -37 ± 1 cm-1 for both. The two CoII complexes likewise exhibit large and nearly axial zfs, but surprisingly, CoCl has positive D = +55 cm-1 while CoCH3 has negative D = -49 cm-1. Theoretical methods were used to probe the electronic structures of the four complexes, which explain the experimental spectra and the zfs parameters.
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Affiliation(s)
- Alexandra L Nagelski
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Majed S Fataftah
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Samuel M Greer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Patrick L Holland
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
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5
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Landaeta VR, Horsley Downie TM, Wolf R. Low-Valent Transition Metalate Anions in Synthesis, Small Molecule Activation, and Catalysis. Chem Rev 2024; 124:1323-1463. [PMID: 38354371 PMCID: PMC10906008 DOI: 10.1021/acs.chemrev.3c00121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 02/16/2024]
Abstract
This review surveys the synthesis and reactivity of low-oxidation state metalate anions of the d-block elements, with an emphasis on contributions reported between 2006 and 2022. Although the field has a long and rich history, the chemistry of transition metalate anions has been greatly enhanced in the last 15 years by the application of advanced concepts in complex synthesis and ligand design. In recent years, the potential of highly reactive metalate complexes in the fields of small molecule activation and homogeneous catalysis has become increasingly evident. Consequently, exciting applications in small molecule activation have been developed, including in catalytic transformations. This article intends to guide the reader through the fascinating world of low-valent transition metalates. The first part of the review describes the synthesis and reactivity of d-block metalates stabilized by an assortment of ligand frameworks, including carbonyls, isocyanides, alkenes and polyarenes, phosphines and phosphorus heterocycles, amides, and redox-active nitrogen-based ligands. Thereby, the reader will be familiarized with the impact of different ligand types on the physical and chemical properties of metalates. In addition, ion-pairing interactions and metal-metal bonding may have a dramatic influence on metalate structures and reactivities. The complex ramifications of these effects are examined in a separate section. The second part of the review is devoted to the reactivity of the metalates toward small inorganic molecules such as H2, N2, CO, CO2, P4 and related species. It is shown that the use of highly electron-rich and reactive metalates in small molecule activation translates into impressive catalytic properties in the hydrogenation of organic molecules and the reduction of N2, CO, and CO2. The results discussed in this review illustrate that the potential of transition metalate anions is increasingly being tapped for challenging catalytic processes with relevance to organic synthesis and energy conversion. Therefore, it is hoped that this review will serve as a useful resource to inspire further developments in this dynamic research field.
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Affiliation(s)
| | | | - Robert Wolf
- University of Regensburg, Institute
of Inorganic Chemistry, 93040 Regensburg, Germany
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6
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Queen JD, Anderson-Sanchez LM, Stennett CR, Rajabi A, Ziller JW, Furche F, Evans WJ. Synthesis of Crystallographically Characterizable Bis(cyclopentadienyl) Sc(II) Complexes: (C 5H 2tBu 3) 2Sc and {[C 5H 3(SiMe 3) 2] 2ScI} 1. J Am Chem Soc 2024; 146:3279-3292. [PMID: 38264991 DOI: 10.1021/jacs.3c11922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
The synthesis of previously unknown bis(cyclopentadienyl) complexes of the first transition metal, i.e., Sc(II) scandocene complexes, has been investigated using C5H2(tBu)3 (Cpttt), C5Me5 (Cp*), and C5H3(SiMe3)2 (Cp″) ligands. Cpttt2ScI, 1, formed from ScI3 and KCpttt, can be reduced with potassium graphite (KC8) in hexanes to generate dark-red crystals of the first crystallographically characterizable bis(cyclopentadienyl) scandium(II) complex, Cpttt2Sc, 2. Complex 2 has a 170.6° (ring centroid)-Sc-(ring centroid) angle and exhibits an eight-line EPR spectrum characteristic of Sc(II) with Aiso = 82.6 MHz (29.6 G). It sublimes at 200 °C at 10-4 Torr and has a melting point of 268-271 °C. Reductions of Cp*2ScI and Cp″2ScI under analogous conditions in hexanes did not provide new Sc(II) complexes, and reduction of Cp*2ScI in benzene formed the Sc(III) phenyl complex, Cp*2Sc(C6H5), 3, by C-H bond activation. However, in Et2O and toluene, reduction of Cp*2ScI at -78 °C gives a dark-red solution, 4, which displays an eight-line EPR pattern like that of 1, but it did not provide thermally stable crystals. Reduction of Cp″2ScI, in THF or Et2O at -35 °C in the presence of 2.2.2-cryptand, yields the green Sc(II) metallocene iodide complex, [K(crypt)][Cp″2ScI], 5, which was identified by X-ray crystallography and EPR spectroscopy and is thermally unstable. The analogous reaction of Cp*2ScI with KC8 and 18-crown-6 in Et2O gave the ligand redistribution product, [Cp*2Sc(18-crown-6-κ2O,O')][Cp*2ScI2], 6, as the only crystalline product. Density functional theory calculations on the electronic structure of these compounds are reported in addition to a steric analysis using the Guzei method.
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Affiliation(s)
- Joshua D Queen
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | | | - Cary R Stennett
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Ahmadreza Rajabi
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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7
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May AM, Deegbey M, Edme K, Lee KJ, Perutz RN, Jakubikova E, Dempsey JL. Electronic Structure and Photophysics of Low Spin d 5 Metallocenes. Inorg Chem 2024; 63:1858-1866. [PMID: 38226604 DOI: 10.1021/acs.inorgchem.3c03451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The electronic structure and photophysics of two low spin metallocenes, decamethylmanganocene (MnCp*2) and decamethylrhenocene (ReCp*2), were investigated to probe their promise as photoredox reagents. Computational studies support the assignment of 2E2 ground state configurations and low energy ligand-to-metal charge transfer transitions for both complexes. Weak emission is observed at room temperature for ReCp*2 with τ = 1.8 ns in pentane, whereas MnCp*2 is not emissive. Calculation of the excited state reduction potentials for both metallocenes reveal their potential potency as excited state reductants (E°'([MnCp*2]+/0*) = -3.38 V and E°'([ReCp*2]+/0*) = -2.61 V vs Fc+/0). Comparatively, both complexes exhibit mild potentials for photo-oxidative processes (E°'([MnCp*2]0*/-) = -0.18 V and E°'([ReCp*2]0*/-) = -0.20 V vs Fc+/0). These results showcase the rich electronic structure of low spin d5 metallocenes and their promise as excited state reductants.
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Affiliation(s)
- Ann Marie May
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Mawuli Deegbey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Kedy Edme
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Katherine J Lee
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Robin N Perutz
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, United Kingdom
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jillian L Dempsey
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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8
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Martín-Fernández C, Ferrer M, Alkorta I, Montero-Campillo MM, Elguero J, Mandado M. Metastable Charged Dimers in Organometallic Species: A Look into Hydrogen Bonding between Metallocene Derivatives. Inorg Chem 2023; 62:16523-16537. [PMID: 37755334 DOI: 10.1021/acs.inorgchem.3c02355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Multiply charged complexes bound by noncovalent interactions have been previously described in the literature, although they were mostly focused on organic and main group inorganic systems. In this work, we show that similar complexes can also be found for organometallic systems containing transition metals and deepen in the reasons behind the existence of these species. We have studied the structures, binding energies, and dissociation profiles in the gas phase of a series of charged hydrogen-bonded dimers of metallocene (Ru, Co, Rh, and Mn) derivatives isoelectronic with the ferrocene dimer. Our results indicate that the carboxylic acid-containing dimers are more strongly bonded and present larger barriers to dissociation than the amide ones and that the cationic complexes tend to be more stable than the anionic ones. Additionally, we describe for the first time the symmetric proton transfer that can occur while in the metastable phase. Finally, we use a density-based energy decomposition analysis to shine light on the nature of the interaction between the dimers.
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Affiliation(s)
| | - Maxime Ferrer
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, 28006 Madrid, Spain
- PhD Programme in Theoretical Chemistry and Computational Modelling, Doctoral School, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, 28006 Madrid, Spain
| | - M Merced Montero-Campillo
- Departamento de Química (Módulo 13, Facultad de Ciencias), Campus de Excelencia UAM-CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - José Elguero
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, 28006 Madrid, Spain
| | - Marcos Mandado
- Departamento de Química Física, Universidade de Vigo, Lagoas-Marcosende s/n, 36310 Vigo, Spain
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Neugebauer H, Vuong HT, Weber JL, Friesner RA, Shee J, Hansen A. Toward Benchmark-Quality Ab Initio Predictions for 3d Transition Metal Electrocatalysts: A Comparison of CCSD(T) and ph-AFQMC. J Chem Theory Comput 2023; 19:6208-6225. [PMID: 37655473 DOI: 10.1021/acs.jctc.3c00617] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Generating accurate ab initio ionization energies for transition metal complexes is an important step toward the accurate computational description of their electrocatalytic reactions. Benchmark-quality data is required for testing existing theoretical methods and developing new ones but is complicated to obtain for many transition metal compounds due to the potential presence of both strong dynamical and static electron correlation. In this regime, it is questionable whether the so-called gold standard, coupled cluster with singles, doubles, and perturbative triples (CCSD(T)), provides the desired level of accuracy─roughly 1-3 kcal/mol. In this work, we compiled a test set of 28 3d metal-containing molecules relevant to homogeneous electrocatalysis (termed 3dTMV) and computed their vertical ionization energies (ionization potentials) with CCSD(T) and phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC) in the def2-SVP basis set. A substantial effort has been made to converge away the phaseless bias in the ph-AFQMC reference values. We assess a wide variety of multireference diagnostics and find that spin-symmetry breaking of the CCSD wave function and the PBE0 density functional correlate well with our analysis of multiconfigurational wave functions. We propose quantitative criteria based on symmetry breaking to delineate correlation regimes inside of which appropriately performed CCSD(T) can produce mean absolute deviations from the ph-AFQMC reference values of roughly 2 kcal/mol or less and outside of which CCSD(T) is expected to fail. We also present a preliminary assessment of density functional theory (DFT) functionals on the 3dTMV set.
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Affiliation(s)
- Hagen Neugebauer
- Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, D-53115 Bonn, Germany
| | - Hung T Vuong
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - John L Weber
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Richard A Friesner
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - James Shee
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Andreas Hansen
- Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, D-53115 Bonn, Germany
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10
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Takebayashi S, Ariai J, Gellrich U, Kartashov SV, Fayzullin RR, Kang HB, Yamane T, Sugisaki K, Sato K. Synthesis and characterization of a formal 21-electron cobaltocene derivative. Nat Commun 2023; 14:4979. [PMID: 37669936 PMCID: PMC10480225 DOI: 10.1038/s41467-023-40557-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/01/2023] [Indexed: 09/07/2023] Open
Abstract
Metallocenes are highly versatile organometallic compounds. The versatility of the metallocenes stems from their ability to stabilize a wide range of formal electron counts. To date, d-block metallocenes with an electron count of up to 20 have been synthesized and utilized in catalysis, sensing, and other fields. However, d-block metallocenes with more than formal 20-electron counts have remained elusive. The synthesis and isolation of such complexes are challenging because the metal-carbon bonds in d-block metallocenes become weaker with increasing deviation from the stable 18-electron configuration. Here, we report the synthesis, isolation, and characterization of a 21-electron cobaltocene derivative. This discovery is based on the ligand design that allows the coordination of an electron pair donor to a 19-electron cobaltocene derivative while maintaining the cobalt-carbon bonds, a previously unexplored synthetic approach. Furthermore, we elucidate the origin of the stability, redox chemistry, and spin state of the 21-electron complex. This study reveals a synthetic method, structure, chemical bonding, and properties of the 21-electron metallocene derivative that expands our conceptual understanding of d-block metallocene chemistry. We expect that this report will open up previously unexplored synthetic possibilities in d-block transition metal chemistry, including the fields of catalysis and materials chemistry.
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Affiliation(s)
- Satoshi Takebayashi
- Science and Technology Group, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
| | - Jama Ariai
- Institute of Organic Chemistry, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, Giessen, D-35392, Germany
| | - Urs Gellrich
- Institute of Organic Chemistry, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, Giessen, D-35392, Germany.
| | - Sergey V Kartashov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, Kazan, 420088, Russian Federation
| | - Robert R Fayzullin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, Kazan, 420088, Russian Federation.
| | - Hyung-Been Kang
- Engineering Section, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Takeshi Yamane
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Kenji Sugisaki
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
- JST PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
- Graduate School of Science and Technology, Keio University, 7-1 Shinkawasaki, Saiwai-ku, Kawasaki, Kanagawa, 212-0032, Japan
- Quantum Computing Center, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Kazunobu Sato
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
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11
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Ullah S, Jensen S, Liu Y, Tan K, Drake H, Zhang G, Huang J, Klimeš J, Driscoll DM, Hermann RP, Zhou HC, Li J, Thonhauser T. Magnetically Induced Binary Ferrocene with Oxidized Iron. J Am Chem Soc 2023; 145:18029-18035. [PMID: 37530761 DOI: 10.1021/jacs.3c05754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Ferrocene is perhaps the most popular and well-studied organometallic molecule, but our understanding of its structure and electronic properties has not changed for more than 70 years. In particular, all previous attempts of chemically oxidizing pure ferrocene by binding directly to the iron center have been unsuccessful, and no significant change in structure or magnetism has been reported. Using a metal organic framework host material, we were able to fundamentally change the electronic and magnetic structure of ferrocene to take on a never-before observed physically stretched/bent high-spin Fe(II) state, which readily accepts O2 from air, chemically oxidizing the iron from Fe(II) to Fe(III). We also show that the binding of oxygen is reversible through temperature swing experiments. Our analysis is based on combining Mößbauer spectroscopy, extended X-ray absorption fine structure, in situ infrared, SQUID, thermal gravimetric analysis, and energy dispersive X-ray fluorescence spectroscopy measurements with ab initio modeling.
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Affiliation(s)
- Saif Ullah
- Department of Physics and Center for Functional Materials, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Stephanie Jensen
- Department of Physics and Center for Functional Materials, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Yanyao Liu
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Kui Tan
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - Hannah Drake
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Guoyu Zhang
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Junjie Huang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jiří Klimeš
- Department of Chemical Physics and Optics, Charles University, 12116 Prague, Czech Republic
| | - Darren M Driscoll
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Raphaël P Hermann
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Hong-Cai Zhou
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jing Li
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Timo Thonhauser
- Department of Physics and Center for Functional Materials, Wake Forest University, Winston-Salem, North Carolina 27109, United States
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12
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Astruc D. From sandwich complexes to dendrimers: journey toward applications to sensing, molecular electronics, materials science, and biomedicine. Chem Commun (Camb) 2023. [PMID: 37191211 DOI: 10.1039/d3cc01175e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
This review links various areas of inorganic chemistry around the themes developed by our research group during the last four decades. It is firstly based on the electronic structure of iron sandwich complexes, showing how the metal electron count dictates their reactivities, with various applications (via C-H activation, C-C bond formation) as reducing and oxidizing agents, redox and electrocatalysts and precursors of dendrimers and catalyst templates through bursting reactions. Various electron-transfer processes and consequences are explored, including the influence of the redox state on the acidity of robust ligands and the possibility to iterate in situ C-H activation and C-C bond formation to build arene-cored dendrimers. Examples of how these dendrimers are functionalized are illustrated using the cross olefin metathesis reactions, with application to the synthesis of soft nanomaterials and biomaterials. Mixed and average valence complexes give rise to remarkable subsequent organometallic reactions, including the salt influence on these reactions. The stereo-electronic aspect of these mixed valencies is pointed out in star-shaped multi-ferrocenes with a frustration effect and other multi-organoiron systems, with the perspective of understanding electron-transfer processes among dendrimer redox sites involving electrostatic effects and application to redox sensing and polymer metallocene batteries. Dendritic redox sensing is summarized for biologically relevant anions such as ATP2- with supramolecular exoreceptor interactions at the dendrimer periphery in parallel with the seminal work on metallocene-derived endoreceptors by Beer's group. This aspect includes the design of the first metallodendrimers that have applications in both redox sensing and micellar catalysis with nanoparticles. These properties provide the opportunity to summarize the biomedical (mostly anticancer) applications of ferrocenes, dendrimers and dendritic ferrocenes in biomedicine (in particular the contribution from our group, but not only). Finally, the use of dendrimers as templates for catalysis is illustrated with numerous reactions including C-C bond formation, click reactions and H2 production reactions.
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Affiliation(s)
- Didier Astruc
- Univ. Bordeaux, ISM, UMR CNRS No. 5255, 351 Cours de la Libération, 33405 Talence Cedex, France.
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13
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Anila S, Suresh CH. Fulleride-metal η 5 sandwich and multi-decker sandwich complexes: A DFT prediction. J Comput Chem 2023; 44:199-208. [PMID: 35417041 DOI: 10.1002/jcc.26860] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/28/2022] [Accepted: 03/28/2022] [Indexed: 12/31/2022]
Abstract
The (C60 CN)- formed by the reaction of CN- with fullerene shows high electron rich character, very similar to C60 ˙- , and it behaves as a large anion. Similar to Cp- , the bulky anion, (C60 CN)- , acts as a strong η5 ligand towards transition metal centers. Previous studies on η5 coordination of fullerene cage are reported for pseudo fullerenes whereas the present study deals with sandwich complexes of (C60 CN)- with Fe(II), Ru(II), Cr(II), Mo(II), and Ni(II) and multi-decker sandwich complexes of CN-fullerides with Fe(II). The structural parameters of these complexes and the corresponding Cp- complexes showed very close resemblance. Analysis of the metal-to-carbon bonding molecular orbitals showed that sandwich complex [Fe(η5 -(C60 CN)- )2 ] exhibit bonding features very similar to that of ferrocene. Also, a 6-fold decrease in the band gap energy is observed for [Fe(η5 -(C60 CN)- )2 ] compared to ferrocene. The energy of dissociation (ΔE) of the ligand (C60 CN)- from [Fe(η5 -(C60 CN)- )2 ] is slightly lower than the ΔE of a Cp* ligand from a ferrocene derivative wherein each cyclopentadienyl unit is substituted with four tertiary butyl groups. The (C60 CN)- ligand behaved as one of the bulkiest ligands in the chemistry of sandwich complexes. Further, the coordinating ability of the dianion, (C60 (CN)2 )2- is evaluated which showed strong coordination ability simultaneously with two metal centers leading to the formation of multi-decker sandwich and pearl-necklace type polymeric structures.
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Affiliation(s)
- Sebastian Anila
- Chemical Sciences and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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14
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Isaeva VA, Gamov GA, Katolikova AS, Pogodina EI. Structure and Stability of Nickel(II) Complexes with Cryptand[2.2.2]. RUSS J GEN CHEM+ 2023. [DOI: 10.1134/s1070363223010085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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15
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Scharnhölz MT, Coburger P, Gravogl L, Klose D, Gamboa‐Carballo JJ, Le Corre G, Bösken J, Schweinzer C, Thöny D, Li Z, Meyer K, Grützmacher H. Bis(imidazolium)-1,3-diphosphete-diide: A Building Block for FeC 2 P 2 Complexes and Clusters. Angew Chem Int Ed Engl 2022; 61:e202205371. [PMID: 35661524 PMCID: PMC9796810 DOI: 10.1002/anie.202205371] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Indexed: 01/07/2023]
Abstract
Reaction of the 6π-electron aromatic four-membered heterocycle (IPr)2 C2 P2 (1) (IPr=1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene) with [Fe2 CO9 ] gives the neutral iron tricarbonyl complex [Fe(CO)3 -η3 -{(IPr)2 C2 P2 }] (2). Oxidation with two equivalents of the ferrocenium salt, [Fe(Cp)2 ](BArF24 ), affords the dicationic tricarbonyl complex [Fe(CO)3 -η4 -{(IPr)2 C2 P2 }](BArF24 )2 (4). The one-electron oxidation proceeds under concomitant loss of one CO ligand to give the paramagnetic dicarbonyl radical cation complex [Fe(CO)2 -η4 -{(IPr)2 C2 P2 }](BArF24 ) (5). Reduction of 5 allows the preparation of the neutral dicarbonyl complex [Fe(CO)2 -η4 -{(IPr)2 C2 P2 }] (6). An analysis by various spectroscopic techniques (57 Fe Mössbauer, EPR) combined with DFT calculations gives insight into differences of the electronic structure within the members of this unique series of iron carbonyl complexes, which can be either described as electron precise or Wade-Mingos clusters.
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Affiliation(s)
| | - Peter Coburger
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Lisa Gravogl
- Department of Chemistry and PharmacyInorganic ChemistryFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Egerlandstr. 191058ErlangenGermany
| | - Daniel Klose
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Juan José Gamboa‐Carballo
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland,Higher Institute of Technologies and Applied Sciences (InSTEC)University of HavanaAve. S. Allende 111010600HavanaCuba
| | - Grégoire Le Corre
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Jonas Bösken
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Clara Schweinzer
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Debora Thöny
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Zhongshu Li
- Lehn Institute of Functional Materials (LIFM)School of ChemistrySun Yat-Sen University510275GuangzhouChina,State Key Laboratory of Elemento-Organic ChemistryNankai University30071TianjinChina
| | - Karsten Meyer
- Department of Chemistry and PharmacyInorganic ChemistryFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Egerlandstr. 191058ErlangenGermany
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
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16
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Conrad A. P. Goodwin. Helv Chim Acta 2022. [DOI: 10.1002/hlca.202200099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Song H, Pietrasiak E, Lee E. Persistent Radicals Derived from N-Heterocyclic Carbenes for Material Applications. Acc Chem Res 2022; 55:2213-2223. [PMID: 35849761 DOI: 10.1021/acs.accounts.2c00222] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Persistent radicals are potential building blocks of novel materials in many fields. Recently, highly stable persistent radicals are considered to be within reach, thanks to several radical stabilization strategies such as spin delocalization and steric protection. N-Heterocyclic carbene (NHC)-derived substituents can be attached to a radical center for these purposes, as illustrated by numerous NHC-stabilized radicals reported in the last two decades.This Account describes our recent work on developing NHC-derived persistent radicals, as well as their prospective applications. Considering that NHCs not only stabilize radicals but also reversibly interact with gas molecules, in 2015 our group reported NHC-nitric oxide (NHC-NO) radicals produced by reversibly trapping nitric oxide (NO) radical gas in NHCs. The resultant compounds were loaded into biocompatible poly(ethylene glycol)-block-poly(caprolactone) (PEG-b-PCL) micelles and injected into tumor-bearing mice. Then, NO release was triggered by high-intensity focused ultrasound irradiation of the tumor tissue. Furthermore, the NHC-NO radicals could also serve as a platform to generate other organic radicals such as oxime ether or iminyl radicals. Apart from medicine-related applications, radicals stabilized by NHCs can be used as energy storage materials. In this context, the triazenyl radical containing two NHC units reported by our laboratory could be a cathode active material in batteries, as an organic alternative to LiCoO2. The subsequently prepared unsymmetrical triazenyl radical derivatives were applied as anolytes in nonaqueous all-organic redox flow batteries. In addition, a ferrocene-based redox flow battery anolyte was obtained by introducing NHC-derived substituents that effectively stabilize the ferrocenate derivatives previously reported only at low temperatures. The batteries containing NHC-supported radicals exhibited high energy efficiency and insignificant radical decomposition over multiple cycles. Finally, toward developing air-persistent organic radicals for flexible devices and MRI contrasting agents, we also highlight our recent air- and physiologically stable organic radicals derived from NHCs. Coordination of tris(pentafluorophenyl)borane to the NHC-NO radical produced a new radical cation that is stable in an organic solvent under air for several months. The readily accessible 1,2-dicarbonyl radical cations generated by the reaction of NHCs with oxalyl chloride are remarkably persistent even in an aqueous solution for several months. They are also highly stable even under physiological conditions, making them particularly attractive potential candidates for organic MRI contrast agents. We hope that this Account will serve as a guide for the future development of stable NHC-derived organic radicals and draw the attention of the synthetic community to their potential applications in material science.
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Affiliation(s)
- Hayoung Song
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
| | - Ewa Pietrasiak
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
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18
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Frei A, Rigby A, Yue TTC, Firth G, Ma MT, Long NJ. To chelate thallium(I) - synthesis and evaluation of Kryptofix-based chelators for 201Tl. Dalton Trans 2022; 51:9039-9048. [PMID: 35640142 DOI: 10.1039/d2dt01074g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
While best known for its toxic properties, thallium has also been explored for applications in nuclear diagnostics and medicine. Indeed, [201Tl]TlCl has been used extensively for nuclear imaging in the past before it was superceded by other radionuclides such as 99mTc. One reason for this loss of interest is the severe lack of suitable organic chelators able to effectively coordinate ionic forms of Tl and deliver it to specific diseased tissue by means of attached biological vectors. Herein, we describe the synthesis and characterisation of a series of Kryptofix 222-based chelators that can be radiolabelled with 201Tl(I) in high radiochemical yields at ambient temperature. We demonstrate that from these simple chelators, targeted derivatives are readily accessible and describe the synthesis and preliminary biological evaluation of a PSMA-targeted 201Tl-labelled Kryptofix 222-peptide conjugate. While the Kryptofix system is demonstrably capable of binding the thallium cation, no PSMA-mediated cell-uptake could be detected with the PSMA conjugate, suggesting that this targeting moiety may not be ideal for use in conjunction with 201Tl.
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Affiliation(s)
- Angelo Frei
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Alex Rigby
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Thomas T C Yue
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - George Firth
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Nicholas J Long
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
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19
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Scharnhölz MT, Coburger P, Gravogl L, Klose D, Gamboa-Carballo JJ, Le Corre G, Bösken J, Schweinzer C, Thöny D, Meyer K, Li Z, Grützmacher H. Bis(imidazolium)‐1,3‐diphosphete‐diide: A Building Block for FeC2P2 Complexes and Clusters. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- M. T. Scharnhölz
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - P. Coburger
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - L. Gravogl
- FAU: Friedrich-Alexander-Universitat Erlangen-Nurnberg Chemie GERMANY
| | - D. Klose
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - J. J. Gamboa-Carballo
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - G. Le Corre
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - J. Bösken
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - C. Schweinzer
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - D. Thöny
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - K. Meyer
- FAU: Friedrich-Alexander-Universitat Erlangen-Nurnberg Chemie GERMANY
| | - Z. Li
- Sun Yat-Sen University Chemistry CHINA
| | - Hansjörg Grützmacher
- ETH Hönggerberg Deptmartment of Chemistry Vladimir Prelog Weg 1 8093 Zürich SWITZERLAND
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20
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Nain S, Khurana R, Ali ME. Harnessing Colossal Magnetic Anisotropy in Sandwiched 3d 2-Metallocenes. J Phys Chem A 2022; 126:2811-2817. [PMID: 35507013 DOI: 10.1021/acs.jpca.2c01605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single-molecule magnets are gaining attention in recent years with the growing focus on achieving higher barriers of magnetization reversal. Metallocenes, owing to their unique sandwiched structure, assure themselves as plausible molecular systems for the development of novel single-molecule magnets (SMMs). Here in this work, we have explicitly investigated metallocenes of first-row transition elements, along with their one-electron-oxidized (cationic) and -reduced (anionic) analogues, for their magnetic anisotropies by adopting multireference ab initio calculations. Herein, we report a high magnetic anisotropy for 3d2 systems among all 3d-metallocenes.
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Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
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21
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Rupf SM, Dimitrova IS, Schröder G, Malischewski M. Preparation and One-Electron Oxidation of Decabromoferrocene. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Susanne M. Rupf
- Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
| | | | - Gabriel Schröder
- Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
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22
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Hierlmeier G, Wolf R. Bulking up Cp BIG: A Penta-Terphenyl Cyclopentadienyl Ligand. Organometallics 2022; 41:776-784. [PMID: 35368714 PMCID: PMC8965875 DOI: 10.1021/acs.organomet.2c00009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Indexed: 12/13/2022]
Abstract
![]()
The modification
of cyclopentadienyl ligands with carefully selected
substituents is a widely used strategy for tuning their steric
and electronic properties. We describe the synthesis of an extremely
bulky penta-terphenyl cyclopentadienyl ligand (CpT5) by
arylation of cyclopentadiene. Deprotonation reactions with various
group 1 metals and bases afforded a complete series of alkali metal
salts MCpT5 (M = Li–Cs). The compounds were isolated
as solvate-free salts, which were characterized by multinuclear nuclear
magnetic resonance spectroscopy, ultraviolet–visible spectroscopy,
and elemental analysis. Single-crystal X-ray diffraction studies of
LiCpT5, NaCpT5 (crystallized as a solvate with
one tetrahydrofuran molecule per formula unit), and KCpT5 revealed the formation of metallocene-like sandwich structures in
the solid state.
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Affiliation(s)
- Gabriele Hierlmeier
- Institute of Inorganic Chemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Robert Wolf
- Institute of Inorganic Chemistry, University of Regensburg, 93040 Regensburg, Germany
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23
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Magnoux C, Mills DP. Metallocene anions: From electrochemical curiosities to isolable complexes. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - David P. Mills
- The University of Manchester School of Chemistry Oxford Road M13 9PL Manchester UNITED KINGDOM
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24
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Abstract
The discovery of ferrocene, [Fe(η5-C5H5)2], seventy years ago has significantly influenced chemical research and provided a key impetus for establishing and rapidly expanding organometallic chemistry, which has continued at a...
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25
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Celedón S, Hamon P, Artigas V, Fuentealba M, Kahlal S, Carrillo D, Saillard JY, Hamon JR, Manzur C. Ferrocene functionalized enantiomerically pure Schiff bases and their Zn( ii) and Pd( ii) complexes: a spectroscopic, crystallographic, electrochemical and computational investigation. NEW J CHEM 2022. [DOI: 10.1039/d1nj06106b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A combination of X-ray diffraction, IR, UV-vis and NMR spectroscopy together with computational methods was used to characterize and study the properties of the title compounds.
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Affiliation(s)
- Salvador Celedón
- Laboratorio de Química Inorgánica, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso, Chile
| | - Paul Hamon
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226, F-35000 Rennes, France
| | - Vania Artigas
- Laboratorio de Cristalografía, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso, Chile
| | - Mauricio Fuentealba
- Laboratorio de Cristalografía, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso, Chile
| | - Samia Kahlal
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226, F-35000 Rennes, France
| | - David Carrillo
- Laboratorio de Química Inorgánica, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso, Chile
| | - Jean-Yves Saillard
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226, F-35000 Rennes, France
| | - Jean-René Hamon
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226, F-35000 Rennes, France
| | - Carolina Manzur
- Laboratorio de Química Inorgánica, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso, Chile
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26
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Yruegas S, Tang H, Bornovski GZ, Su X, Sung S, Hall MB, Nippe M, Martin CD. Nickel-Borolide Complexes and Their Complex Electronic Structure. Inorg Chem 2021; 60:16160-16167. [PMID: 34637613 DOI: 10.1021/acs.inorgchem.1c01845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Borolides (BC42-) can be considered as dianionic heterocyclic analogues of monoanionic cyclopentadienides. Although both are formally six-π-electron donors, we herein demonstrate that the electronic structure of their corresponding transition metal complexes differs significantly, leading to altered properties. Specifically, the 18-electron sandwich complex Ni(iPr2NBC4Ph2)2 (1) features an ∼90° angle between the Ni-B-N planes and is best described as a combination of three limiting resonance structures with the major contribution stemming from a formally Ni2+ species bound to two monoanionic radical (BC4•-) ligands. Compound 1 displays two sequential one-electron oxidation events over a small potential range of <0.2 V, which strikingly contrasts the large potential separations between redox partners in the family of metallocenes, and the potential reasons for this unusual observation are discussed.
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Affiliation(s)
- Sam Yruegas
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Hao Tang
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Gayle Z Bornovski
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Xiaojun Su
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Siyoung Sung
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Michael B Hall
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Michael Nippe
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Caleb D Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
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27
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Song H, Kwon G, Citek C, Jeon S, Kang K, Lee E. Pyrrolinium-Substituted Persistent Zwitterionic Ferrocenate Derivative Enabling the Application of Ferrocene Anolyte. ACS APPLIED MATERIALS & INTERFACES 2021; 13:46558-46565. [PMID: 34558898 DOI: 10.1021/acsami.1c11571] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Here, we report the imidazolium-/pyrrolinium-substituted persistent zwitterionic ferrocenate derivatives, which were characterized by electron paramagnetic resonance (EPR) and 57Fe Mössbauer spectroscopy. Additional theoretical studies on these zwitterionic ferrocenate derivatives clearly explain the origin of their thermal stability and the orbital interactions between iron and imidazolium-/pyrrolinium-substituted zwitterionic cyclopentadienyl ligand. Exploiting the facile Fe(II/I) redox chemistry, we successfully demonstrated that the pyrrolinium-substituted ferrocene derivative can be applied as an example of derivatized ferrocene anolyte for redox-flow batteries. These zwitterionic ferrocenate derivatives will not only deepen our understanding of the intrinsic chemistry of ferrocenate but have the potential to open the way for the rational design of metallocenate derivatives for various applications.
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Affiliation(s)
- Hayoung Song
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Giyun Kwon
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Cooper Citek
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
| | - Seungwon Jeon
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Kisuk Kang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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28
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Wang W, Chamkina ES, Guisasola Cal E, Di Silvio D, Moro MM, Moya S, Hamon JR, Astruc D, Shifrina ZB. Ferrocenyl-terminated polyphenylene-type "click" dendrimers as supports for efficient gold and palladium nanocatalysis. Dalton Trans 2021; 50:11852-11860. [PMID: 34369506 DOI: 10.1039/d1dt01865e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Although dendrimer supports have been known as key parts of nanocatalysts, the capability of rigid dendrimers for this function has not yet been reported. Here, the study is focused on ferrocenylmethylenetriazolyl-terminated dendrimers (FcMTPD) as supports of remarkably efficient nanogold and nanopalladium catalysts. A biphasic system is elaborated to evaluate the catalytic activity of FcMTPD-supported Au and Pd nanoparticles (NPs) for the reduction of 4-nitrophenol to 4-aminophenol by NaBH4 at 20 °C, and FcMTPD-supported PdNPs are found to be the best nanocatalysts with a rate constant kapp = 7.8 × 10-2 s-1. Excellent catalytic results are also obtained in this reaction for FcMTPD-supported AuNPs with a rate constant kapp = 5.6 × 10-2 s-1. For both Pd NPs and AuNPs, the kinetic results are shown to strongly depend on the method of preparation of these NPs that influences the NP size and thus their catalytic efficiency. The FcMTPD-stabilized PdNPs are easily recovered and reused at least 13 times, and their catalytic performance displays only a slight decrease during the first seven runs.
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Affiliation(s)
- Wenjuan Wang
- Univ. Bordeaux, ISM, UMR CNRS 5255, 33405 Talence Cedex, France.
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29
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Yamaura H, Yamamoto K, Murahashi T. Selective dimerization of a trinuclear mixed-metal sandwich complex: construction of an axially chiral metal skeleton. Chem Commun (Camb) 2021; 57:9120-9123. [PMID: 34498631 DOI: 10.1039/d1cc03719f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Certain metal sandwich complexes undergo dimerization through metal-metal bond formation. Here, we found that a reductive dimerization of mixed-metal Pd2Pt or PdPt2 sandwich complexes proceeds through selective Pt-Pt bond formation. A restricted rotation at the Pt-Pt bond of the PdPt2 dimer gave a unique axially chiral structure derived from a heterometal arrangement in a mixed-metal cluster.
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Affiliation(s)
- Hiroshige Yamaura
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan.
| | - Koji Yamamoto
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan.
| | - Tetsuro Murahashi
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan.
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30
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Dong Y, Li T, Cai D, Yang S, Zhou X, Nie H, Yang Z. Progress and Prospect of Organic Electrocatalysts in Lithium-Sulfur Batteries. Front Chem 2021; 9:703354. [PMID: 34336789 PMCID: PMC8322034 DOI: 10.3389/fchem.2021.703354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
Lithium-sulfur (Li-S) batteries featured by ultra-high energy density and cost-efficiency are considered the most promising candidate for the next-generation energy storage system. However, their pragmatic applications confront several non-negligible drawbacks that mainly originate from the reaction and transformation of sulfur intermediates. Grasping and catalyzing these sulfur species motivated the research topics in this field. In this regard, carbon dopants with metal/metal-free atoms together with transition-metal complex, as traditional lithium polysulfide (LiPS) propellers, exhibited significant electrochemical performance promotions. Nevertheless, only the surface atoms of these host-accelerators can possibly be used as active sites. In sharp contrast, organic materials with a tunable structure and composition can be dispersed as individual molecules on the surface of substrates that may be more efficient electrocatalysts. The well-defined molecular structures also contribute to elucidate the involved surface-binding mechanisms. Inspired by these perceptions, organic electrocatalysts have achieved a great progress in recent decades. This review focuses on the organic electrocatalysts used in each part of Li-S batteries and discusses the structure-activity relationship between the introduced organic molecules and LiPSs. Ultimately, the future developments and prospects of organic electrocatalysts in Li-S batteries are also discussed.
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Affiliation(s)
- Yangyang Dong
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Tingting Li
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Dong Cai
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Shuo Yang
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
- College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou, China
| | - Xuemei Zhou
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Huagui Nie
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Zhi Yang
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
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31
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McDonagh AW, McNeil BL, Patrick BO, Ramogida CF. Synthesis and Evaluation of Bifunctional [2.2.2]-Cryptands for Nuclear Medicine Applications. Inorg Chem 2021; 60:10030-10037. [PMID: 34159785 DOI: 10.1021/acs.inorgchem.1c01274] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
For the first time, synthesis of bifunctional [2.2.2]-cryptands (CRYPT) and demonstration of radiolabeling with lead(II) (Pb2+) isotopes are disclosed herein. The synthesis is convenient and high-yielding and gives access to three distinct bifunctional handles (azide (-N3), isothiocyanate (-NCS), and tetrazine (-Tz)) that can enable the construction of radioimmunoconjugates for targeted and pretargeted therapy. Proof-of-principle CRYPT radiolabeling was successful with lead-203 ([203Pb]Pb2+) and demonstrated complexation efficiency superior to that of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and efficiency comparable to that of the current industry standard TCMC (1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane). In vitro human serum stability assays demonstrated excellent [203Pb]Pb-CRYPT stability over 72 h (91.7 ± 0.56%; n = 3). [203Pb]Pb-CRYPT-radioimmunoconjugates were synthesized from the corresponding CRYPT-immunoconjugate or by conjugating [203Pb]Pb-Tz-CRYPT to transcyclooctene modified trastuzumab (TCO-trastuzumab) via the inverse electron-demand Diels-Alder (IEEDA) reaction. This investigation reveals the potential for CRYPT ligands to become new industry standards for therapeutic and diagnostic radiometals in radiopharmaceutical elaboration.
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Affiliation(s)
- Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Brooke L McNeil
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
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32
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Khan FST, Waldbusser AL, Carrasco MC, Pourhadi H, Hematian S. Synthetic, spectroscopic, structural, and electrochemical investigations of ferricenium derivatives with weakly coordinating anions: ion pairing, substituent, and solvent effects. Dalton Trans 2021; 50:7433-7455. [PMID: 33970173 DOI: 10.1039/d1dt01192h] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A facile and effective strategy for the preparation of a series of ferricenium complexes bearing either electron-donating or electron-withdrawing substituents with weakly coordinating anions such as [B(C6F5)4]- or SbF6- is reported. These systems were thoroughly investigated for their ground state electronic structures in both solution and solid states using infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies as well as single crystal X-ray crystallography and electrochemical measurements. The X-ray structures of the six electron-deficient ferricenium derivatives are of particular interest as only a handful (∼5) of such derivatives have been structurally characterized to date. Comparison of the structural data for both neutral and oxidized derivatives reveals that the nature of the substituents on the cyclopentadienyl (Cp) ligands displays a more significant impact on the metal-ligand separations (FeCt) in the oxidized species than in their neutral analogs. Our 1H-NMR measurements corroborate that in the neutral ferrocene derivatives, electron-donating ring substitutions lead to a greater shielding of the ring protons while electron-withdrawing groups via induction deshield the nearby ring protons. However, the data for the paramagnetic ferricenium derivatives reveals that this substitutional behavior is more complex and fundamentally reversed, which is further supported by our structural studies. We ascribe this reversal of behavior in the ferricenium derivatives to the δ back-donation from the iron atom into the Cp rings which can lead to the overall shielding of the ring protons. Interestingly, our NMR results for the electron-deficient ferricenium derivatives in solution also indicate a direct correlation between the solvent dielectric constant and the energy barrier for rotation around the metal-ligand bond in these systems, whereas such a correlation is absent or not significant in the case of the electron-rich ferricenium species or the corresponding neutral ferrocene analogs. In this work, we also present the electrochemical behavior of the corresponding ferricenium/ferrocene redox couples including potential values (E1/2), peak-to-peak separation (ΔE1/2), and diffusion coefficients (D) of the redox active species in order to provide a concise outline of these data in one place. Our electrochemical studies involved three different solvents and two supporting electrolytes. Notably, our findings point to the significant effect of ion-pairing in lowering the energy necessary for reduction of the ferricenium ion and E1/2 in lower-polarity media. This has significant implications in applications of the ferrocene or ferricenium derivatives as redox agents in low-polarity solvents where an accurate determination of redox potential is critical.
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Affiliation(s)
- Firoz Shah Tuglak Khan
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
| | - Amy L Waldbusser
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
| | - Maria C Carrasco
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
| | - Hadi Pourhadi
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
| | - Shabnam Hematian
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
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33
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Walawalkar MG, Pandey P, Murugavel R. The Redox Journey of Iconic Ferrocene: Ferrocenium Dications and Ferrocenate Anions. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Priya Pandey
- Department of Chemistry IIT Bombay Mumbai 400076 India
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34
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Walawalkar MG, Pandey P, Murugavel R. The Redox Journey of Iconic Ferrocene: Ferrocenium Dications and Ferrocenate Anions. Angew Chem Int Ed Engl 2021; 60:12632-12635. [PMID: 33915016 DOI: 10.1002/anie.202101770] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 11/08/2022]
Abstract
The recent discoveries of both dicationic and monoanionic ferrocene derivatives throw light on the effect of the substituents on the C5 ring as well as the choice of redox agents and solvent system in the preparation of previously believed to be difficult synthetic targets. These oxidized and reduced forms of ferrocene are of interest to spectroscopists, magnetochemists, and theoreticians.
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Affiliation(s)
| | - Priya Pandey
- Department of Chemistry, IIT Bombay, Mumbai, 400076, India
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35
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Greer SM, Üngor Ö, Beattie RJ, Kiplinger JL, Scott BL, Stein BW, Goodwin CAP. Low-spin 1,1'-diphosphametallocenates of chromium and iron. Chem Commun (Camb) 2021; 57:595-598. [PMID: 33338086 DOI: 10.1039/d0cc06518h] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report two anionic diphosphametallocenates, [K(2.2.2-crypt)][M(PC4Me4)2] (M = Cr, 2-Cr; Fe, 2-Fe). Both are low-spin (S = ½) by EPR spectroscopy and SQUID magnetometry. This contrasts the high-spin (S = 3/2) ferrocenate, [K(2.2.2-crypt)][Fe(C5H2-1,2,4-tBu)2] (4-Fe). Quantum chemical calculations suggest this is due to significant differences in ligand field splitting of the d-orbitals which also explain structural features in the 2-M complexes.
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Affiliation(s)
- Samuel M Greer
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA and Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Ökten Üngor
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Ross J Beattie
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | | | - Brian L Scott
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Benjamin W Stein
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Conrad A P Goodwin
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. and Department of Chemistry, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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