1
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Valerio L, Hakey BM, Leary DC, Stockdale E, Brennessel WW, Milsmann C, Matson EM. Synthesis and Characterization of Isostructural Th(IV) and U(IV) Pyridine Dipyrrolide Complexes. Inorg Chem 2024; 63:9610-9623. [PMID: 38377955 PMCID: PMC11134498 DOI: 10.1021/acs.inorgchem.3c04391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/22/2024]
Abstract
A series of pyridine dipyrrolide actinide(IV) complexes, (MesPDPPh)AnCl2(THF) and An(MesPDPPh)2 (An = U, Th, where (MesPDPPh) is the doubly deprotonated form of 2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine), have been prepared. Characterization of all four complexes has been performed through a combination of solid- and solution-state methods, including elemental analysis, single crystal X-ray diffraction, and electronic absorption and nuclear magnetic resonance spectroscopies. Collectively, these data confirm the formation of the mono- and bis-ligated species. Time-dependent density functional theory has been performed on all four An(IV) complexes, providing insight into the nature of electronic transitions that are observed in the electronic absorption spectra of these compounds. Room temperature, solution-state luminescence of the actinide complexes is presented. Both Th(IV) derivatives exhibit strong photoluminescence; in contrast, the U(IV) species are nonemissive.
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Affiliation(s)
- Leyla
R. Valerio
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Brett M. Hakey
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Dylan C. Leary
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Erin Stockdale
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William W. Brennessel
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Carsten Milsmann
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Ellen M. Matson
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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2
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Jones R, Cowin RA, Ivalo II, Chekulaev D, Roseveare TM, Rice CR, Weinstein JA, Elliott PIP, Scattergood PA. A Near-Infrared Luminescent Cr(III) N-Heterocyclic Carbene Complex. Inorg Chem 2024; 63:8526-8530. [PMID: 38696219 PMCID: PMC11094792 DOI: 10.1021/acs.inorgchem.4c01270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 05/14/2024]
Abstract
Photoluminescent coordination complexes of Cr(III) are of interest as near-infrared spin-flip emitters. Here, we explore the preparation, electrochemistry, and photophysical properties of the first two examples of homoleptic N-heterocyclic carbene complexes of Cr(III), featuring 2,6-bis(imidazolyl)pyridine (ImPyIm) and 2-imidazolylpyridine (ImPy) ligands. The complex [Cr(ImPy)3]3+ displays luminescence at 803 nm on the microsecond time scale (13.7 μs) from a spin-flip doublet excited state, which transient absorption spectroscopy reveals to be populated within several picoseconds following photoexcitation. Conversely, [Cr(ImPyIm)2]3+ is nonemissive and has a ca. 500 ps excited-state lifetime.
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Affiliation(s)
- Robert
W. Jones
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Rory A. Cowin
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Iona I. Ivalo
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Dimitri Chekulaev
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Thomas M. Roseveare
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Craig R. Rice
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Julia. A. Weinstein
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Paul I. P. Elliott
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Paul A. Scattergood
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
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3
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Krämer K, Schmitz M, Kelm H, van Wüllen C, Krüger HJ. Unexpected Reduction of a Coordinated Diazapyridinophane Ligand Bound to Chromium(III) Ion Leading to Delocalization of the Unpaired Electron across Two Isolated Pyridine Units. Chemistry 2024; 30:e202301099. [PMID: 37903737 DOI: 10.1002/chem.202301099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 10/06/2023] [Accepted: 10/27/2023] [Indexed: 11/01/2023]
Abstract
In the tetraazamacrocyclic ligand N,N'-dimethyl-2,11-diaza-[3.3](2,6)pyridinophane (L-N4 Me2 ), the two pyridine units are separated from each other by sp3 -hybridized triatomic bridges. Such electronically isolated pyridine moieties are considerably less prone to reductions than di- or triimines. A detailed structural, magnetic, and spectroscopic investigation of the complexes [Cr(L-N4 Me2 )(OAc)2 ] and [Cr(L-N4 Me2 )(OAc)2 ](PF6 ), in combination with theoretical calculations, reveals that the reduced complex must be described as a chromium(III) ion coordinated to the anionic radical ligand (L-N4 Me2 )⋅- rather than a low-spin chromium(II) ion bound to closed-shell ligands. Thus, it is, to the best of our knowledge, only the second example of a stable and structurally characterized metal complex containing a reduced isolated pyridine unit. The stability is attributed to the delocalization of the unpaired electron across the two pyridine units, mediated by their interaction to the metal ion.
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Affiliation(s)
- Kristin Krämer
- RPTU Kaiserslautern-Landau, Department of Chemistry, Erwin-Schrödinger Straße 54, 67663, Kaiserslautern, Germany
| | - Markus Schmitz
- RPTU Kaiserslautern-Landau, Department of Chemistry, Erwin-Schrödinger Straße 54, 67663, Kaiserslautern, Germany
| | - Harald Kelm
- RPTU Kaiserslautern-Landau, Department of Chemistry, Erwin-Schrödinger Straße 54, 67663, Kaiserslautern, Germany
| | - Christoph van Wüllen
- RPTU Kaiserslautern-Landau, Department of Chemistry and Forschungszentrum OPTIMAS, Erwin-Schrödinger Straße 54, 67663, Kaiserslautern, Germany
| | - Hans-Jörg Krüger
- RPTU Kaiserslautern-Landau, Department of Chemistry, Erwin-Schrödinger Straße 54, 67663, Kaiserslautern, Germany
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4
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Kitzmann WR, Hunger D, Reponen APM, Förster C, Schoch R, Bauer M, Feldmann S, van Slageren J, Heinze K. Electronic Structure and Excited-State Dynamics of the NIR-II Emissive Molybdenum(III) Analogue to the Molecular Ruby. Inorg Chem 2023; 62:15797-15808. [PMID: 37718553 DOI: 10.1021/acs.inorgchem.3c02186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Photoactive chromium(III) complexes saw a conceptual breakthrough with the discovery of the prototypical molecular ruby mer-[Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine), which shows intense long-lived near-infrared (NIR) phosphorescence from metal-centered spin-flip states. In contrast to the numerous studies on chromium(III) photophysics, only 10 luminescent molybdenum(III) complexes have been reported so far. Here, we present the synthesis and characterization of mer-MoX3(ddpd) (1, X = Cl; 2, X = Br) and cisfac-[Mo(ddpd)2]3+ (cisfac-[3]3+), an isomeric heavy homologue of the prototypical molecular ruby. For cisfac-[3]3+, we found strong zero-field splitting using magnetic susceptibility measurements and electron paramagnetic resonance spectroscopy. Electronic spectra covering the spin-forbidden transitions show that the spin-flip states in mer-1, mer-2, and cisfac-[3]3+ are much lower in energy than those in comparable chromium(III) compounds. While all three complexes show weak spin-flip phosphorescence in NIR-II, the emission of cisfac-[3]3+ peaking at 1550 nm is particularly low in energy. Femtosecond transient absorption spectroscopy reveals a short excited-state lifetime of 1.4 ns, 6 orders of magnitude shorter than that of mer-[Cr(ddpd)2]3+. Using density functional theory and ab initio multireference calculations, we break down the reasons for this disparity and derive principles for the design of future stable photoactive molybdenum(III) complexes.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - David Hunger
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Antti-Pekka M Reponen
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Roland Schoch
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Sascha Feldmann
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Joris van Slageren
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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5
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Kitzmann WR, Bertrams MS, Boden P, Fischer AC, Klauer R, Sutter J, Naumann R, Förster C, Niedner-Schatteburg G, Bings NH, Hunger J, Kerzig C, Heinze K. Stable Molybdenum(0) Carbonyl Complex for Upconversion and Photoredox Catalysis. J Am Chem Soc 2023. [PMID: 37478053 DOI: 10.1021/jacs.3c03832] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Photoactive complexes with earth-abundant metals have attracted increasing interest in the recent years fueled by the promise of sustainable photochemistry. However, sophisticated ligands with complicated syntheses are oftentimes required to enable photoactivity with nonprecious metals. Here, we combine a cheap metal with simple ligands to easily access a photoactive complex. Specifically, we synthesize the molybdenum(0) carbonyl complex Mo(CO)3(tpe) featuring the tripodal ligand 1,1,1-tris(pyrid-2-yl)ethane (tpe) in two steps with a high overall yield. The complex shows intense deep-red phosphorescence with excited state lifetimes of several hundred nanoseconds. Time-resolved infrared spectroscopy and laser flash photolysis reveal a triplet metal-to-ligand charge-transfer (3MLCT) state as the lowest excited state. Temperature-dependent luminescence complemented by density functional theory (DFT) calculations suggest thermal deactivation of the 3MLCT state via higher lying metal-centered states in analogy to the well-known photophysics of [Ru(bpy)3]2+. Importantly, we found that the title compound is very photostable due to the lack of labilized Mo-CO bonds (as caused by trans-coordinated CO) in the facial configuration of the ligands. Finally, we show the versatility of the molybdenum(0) complex in two applications: (1) green-to-blue photon upconversion via a triplet-triplet annihilation mechanism and (2) photoredox catalysis for a green-light-driven dehalogenation reaction. Overall, our results establish tripodal carbonyl complexes as a promising design strategy to access stable photoactive complexes of nonprecious metals avoiding tedious multistep syntheses.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Maria-Sophie Bertrams
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Pit Boden
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Alexander C Fischer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - René Klauer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Sutter
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Gereon Niedner-Schatteburg
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Nicolas H Bings
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Hunger
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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6
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Hakey BM, Leary DC, Lopez LM, Valerio LR, Brennessel WW, Milsmann C, Matson EM. Synthesis and Characterization of Pyridine Dipyrrolide Uranyl Complexes. Inorg Chem 2022; 61:6182-6192. [PMID: 35420825 PMCID: PMC9044449 DOI: 10.1021/acs.inorgchem.2c00348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The first actinide complexes of the pyridine dipyrrolide (PDP) ligand class, (MesPDPPh)UO2(THF) and (Cl2PhPDPPh)UO2(THF), are reported as the UVI uranyl adducts of the bulky aryl substituted pincers (MesPDPPh)2- and (Cl2PhPDPPh)2- (derived from 2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine (H2MesPDPPh, Mes = 2,4,6-trimethylphenyl), and 2,6-bis(5-(2,6-dichlorophenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine (H2Cl2PhPDPPh, Cl2Ph = 2,6-dichlorophenyl), respectively). Following the in situ deprotonation of the proligand with lithium hexamethyldisilazide to generate the corresponding dilithium salts (e.g., Li2ArPDPPh, Ar = Mes of Cl2Ph), salt metathesis with [UO2Cl2(THF)2]2 afforded both compounds in moderate yields. The characterization of each species has been undertaken by a combination of solid- and solution-state methods, including combustion analysis, infrared, electronic absorption, and NMR spectroscopies. In both complexes, single-crystal X-ray diffraction has revealed a distorted octahedral geometry in the solid state, enforced by the bite angle of the rigid meridional (ArPDPPh)2- pincer ligand. The electrochemical analysis of both compounds by cyclic voltammetry in tetrahydrofuran (THF) reveals rich redox profiles, including events assigned as UVI/UV redox couples. A time-dependent density functional theory study has been performed on (MesPDPPh)UO2(THF) and provides insight into the nature of the transitions that comprise its electronic absorption spectrum.
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Affiliation(s)
- Brett M Hakey
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Dylan C Leary
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lauren M Lopez
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Leyla R Valerio
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William W Brennessel
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Carsten Milsmann
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Ellen M Matson
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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7
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Tomilin DN, Sobenina LN, Saliy IV, Ushakov IA, Belogolova AM, Trofimov BA. Substituted pyrrolyl-cyanopyridines on the platform of acylethynylpyrroles via their 1 : 2 annulation with acetonitrile under the action of lithium metal. NEW J CHEM 2022. [DOI: 10.1039/d2nj02011d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A facile one-pot synthesis of 2-(pyrrolyl)-4-aryl(hetaryl)-5-cyano-6-methylpyridines in 63–87% yield via the cyclization of available acylethynylpyrroles with two molecules of acetonitrile under the action of lithium metal at room temperature has been developed.
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Affiliation(s)
- Denis N. Tomilin
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
| | - Lyubov N. Sobenina
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
| | - Ivan V. Saliy
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
| | - Igor A. Ushakov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
| | - Aleksandra M. Belogolova
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
| | - Boris A. Trofimov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia
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8
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Hakey BM, Leary DC, Rodriguez JG, Martinez JC, Vaughan NB, Darmon JM, Akhmedov NG, Petersen JL, Dolinar BS, Milsmann C. Effects of 2,6‐Dichlorophenyl Substituents on the Coordination Chemistry of Pyridine Dipyrrolide Iron Complexes. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202100117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Brett M. Hakey
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Dylan C. Leary
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Jose G. Rodriguez
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Jordan C. Martinez
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Nicholas B. Vaughan
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | | | - Novruz G. Akhmedov
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Jeffrey L. Petersen
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Brian S. Dolinar
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
| | - Carsten Milsmann
- C. Eugene Bennett Department of Chemistry West Virginia University Morgantown, West Virginia USA
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9
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Dias HVR, Pramanik A. Nickel(II) carbonyl, ammonia, and aceto-nitrile complexes supported by a pyridine dipyrrolide pincer ligand. Acta Crystallogr E Crystallogr Commun 2020; 76:1741-1747. [PMID: 33209345 PMCID: PMC7643235 DOI: 10.1107/s2056989020013341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 10/05/2020] [Indexed: 01/12/2023]
Abstract
The synthesis, isolation and crystal structures of nickel(II) carbonyl, aceto-nitrile and ammonia complexes supported by a dianionic, pyridine dipyrrolide pincer ligand [pyrr2py]2-, namely, carbonyl[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]-nickel(II), [Ni(C41H33N3)(CO)], ammine[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]nickel(II), [Ni(C41H33N3)(NH3)], and (aceto-nitrile-κN)[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CH3CN)], as well as the free ligand 2,6-bis-(3,5-di-p-tolyl-pyrrol-2-yl)pyridine, C41H35N3 or [pyrr2py]H2 are reported. The nickel complexes are four-coordinate and adopt a square-planar geometry. The CO stretch of the nickel-bound carbon monoxide ligand of [pyrr2py]Ni(CO) has been observed at 2101 cm-1. The ammonia and aceto-nitrile complexes, [pyrr2py]Ni(NH3) and [pyrr2py]Ni(NCMe) feature all-nitro-gen coordination spheres around nickel consisting of different N-donor ligand types.
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Affiliation(s)
- H. V. Rasika Dias
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA
| | - Abhijit Pramanik
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA
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10
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Zhang Y, Leary DC, Belldina AM, Petersen JL, Milsmann C. Effects of Ligand Substitution on the Optical and Electrochemical Properties of (Pyridinedipyrrolide)zirconium Photosensitizers. Inorg Chem 2020; 59:14716-14730. [PMID: 32975946 DOI: 10.1021/acs.inorgchem.0c02343] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of seven bis(pyridinedipyrrolide)zirconium complexes, Zr(R1PDPR2)2, where [R1PDPR2]2- is the doubly deprotonated form of [2,6-bis(5-R1-3-R2-1H-pyrrol-2-yl)pyridine], were prepared and characterized in solution by NMR, UV/vis absorption, and emission spectroscopy and cyclic voltammetry. The molecular structures were determined by single-crystal X-ray crystallography. All complexes exhibit remarkably long emission lifetimes (τ = 190-576 μs) with high quantum efficiencies (ΦPL = 0.10-0.38) upon excitation with visible light in a benzene solution. The substituents on the pyrrolide rings were shown to have significant effects on the photoluminescence and electrochemical properties of these compounds. The R2 substituents (R2 = H, Me, Ph, or C6F5) show only limited effects on the absorption and emission profiles of the complexes but allow systematic tuning of the ground- and excited-state redox potentials over a range of almost 600 mV. The R1 substituents (R1 = H, Me, Ph, or 2,4,6-Me3Ph) influence both the optical and electrochemical properties through electronic effects. Additionally, the R1 substituents have profound consequences for the structural flexibility and overall stability of the compounds. Distortions of the Zr(PDP)2 core from idealized D2d symmetry in the solid state can be traced to the steric profiles of the R1 substituents and correlate with the observed Stokes shifts for each compound. The complex with the smallest ligand system, Zr(HPDPH)2, coordinates two additional solvent molecules in a tetrahydrofuran (THF) solution, which allowed the isolation of photoluminescent, eight-coordinate Zr(HPDPH)2(THF)2. The photoredox catalytic dehalogenation of aryl iodides and aryl chlorides using the most reducing derivative, Zr(MePDPMe)2, highlights the potential of Zr(PDP)2 photosensitizers to promote challenging reductive transformations under mild conditions upon excitation with green light.
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Affiliation(s)
- Yu Zhang
- C. Eugene Bennett Department of Chemistry, West Virginia University (WVU), 100 Prospect Street, Morgantown, West Virginia 26506, United States
| | - Dylan C Leary
- C. Eugene Bennett Department of Chemistry, West Virginia University (WVU), 100 Prospect Street, Morgantown, West Virginia 26506, United States
| | - Anne M Belldina
- C. Eugene Bennett Department of Chemistry, West Virginia University (WVU), 100 Prospect Street, Morgantown, West Virginia 26506, United States
| | - Jeffrey L Petersen
- C. Eugene Bennett Department of Chemistry, West Virginia University (WVU), 100 Prospect Street, Morgantown, West Virginia 26506, United States
| | - Carsten Milsmann
- C. Eugene Bennett Department of Chemistry, West Virginia University (WVU), 100 Prospect Street, Morgantown, West Virginia 26506, United States
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11
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Sorsche D, Miehlich ME, Searles K, Gouget G, Zolnhofer EM, Fortier S, Chen CH, Gau M, Carroll PJ, Murray CB, Caulton KG, Khusniyarov MM, Meyer K, Mindiola DJ. Unusual Dinitrogen Binding and Electron Storage in Dinuclear Iron Complexes. J Am Chem Soc 2020; 142:8147-8159. [DOI: 10.1021/jacs.0c01488] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Dieter Sorsche
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Matthias E. Miehlich
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Keith Searles
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Guillaume Gouget
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Eva M. Zolnhofer
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Skye Fortier
- Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Chun-Hsing Chen
- Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Michael Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J. Carroll
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christopher B. Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kenneth G. Caulton
- Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Marat M. Khusniyarov
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Karsten Meyer
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Daniel J. Mindiola
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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12
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Tanabe Y, Sekiguchi Y, Tanaka H, Konomi A, Yoshizawa K, Kuriyama S, Nishibayashi Y. Preparation and reactivity of molybdenum complexes bearing pyrrole-based PNP-type pincer ligand. Chem Commun (Camb) 2020; 56:6933-6936. [DOI: 10.1039/d0cc02852e] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Molybdenum complexes bearing an anionic pyrrole-based PNP-type pincer ligand have been prepared and have been found to work as catalysts for the conversion of N2 into NH3 under ambient conditions.
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Affiliation(s)
- Yoshiaki Tanabe
- Department of Systems Innovation
- School of Engineering
- The University of Tokyo
- Hongo
- Bunkyo-ku
| | - Yoshiya Sekiguchi
- Department of Systems Innovation
- School of Engineering
- The University of Tokyo
- Hongo
- Bunkyo-ku
| | - Hiromasa Tanaka
- Institute for Materials Chemistry and Engineering
- Kyushu University
- Nishi-ku
- Fukuoka 819-0395
- Japan
| | - Asuka Konomi
- Institute for Materials Chemistry and Engineering
- Kyushu University
- Nishi-ku
- Fukuoka 819-0395
- Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering
- Kyushu University
- Nishi-ku
- Fukuoka 819-0395
- Japan
| | - Shogo Kuriyama
- Department of Systems Innovation
- School of Engineering
- The University of Tokyo
- Hongo
- Bunkyo-ku
| | - Yoshiaki Nishibayashi
- Department of Systems Innovation
- School of Engineering
- The University of Tokyo
- Hongo
- Bunkyo-ku
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13
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Treiling S, Wang C, Förster C, Reichenauer F, Kalmbach J, Boden P, Harris JP, Carrella LM, Rentschler E, Resch‐Genger U, Reber C, Seitz M, Gerhards M, Heinze K. Luminescence and Light-Driven Energy and Electron Transfer from an Exceptionally Long-Lived Excited State of a Non-Innocent Chromium(III) Complex. Angew Chem Int Ed Engl 2019; 58:18075-18085. [PMID: 31600421 PMCID: PMC6916301 DOI: 10.1002/anie.201909325] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/01/2019] [Indexed: 01/10/2023]
Abstract
Photoactive metal complexes employing Earth-abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non-innocence to tune the luminescence and photochemistry of the excited state of the [CrN6 ] chromophore [Cr(tpe)2 ]3+ with close to octahedral symmetry (tpe=1,1,1-tris(pyrid-2-yl)ethane). [Cr(tpe)2 ]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2 ]3+ are redox non-innocent, leading to reversible reductive chemistry. The excited state redox potential and lifetime of [Cr(tpe)2 ]3+ surpass those of the classical photosensitizer [Ru(bpy)3 ]2+ (bpy=2,2'-bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n-butyl)amine).
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Affiliation(s)
- Steffen Treiling
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Cui Wang
- Division BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard-Willstätter-Straße 1112489BerlinGermany
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Christoph Förster
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Florian Reichenauer
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Jens Kalmbach
- Institute of Inorganic ChemistryUniversity of TübingenAuf der Morgenstelle 1872076TübingenGermany
| | - Pit Boden
- Department of Chemistry and Research Center OptimasTU KaiserslauternErwin-Schrödinger-Straße67663KaiserslauternGermany
| | - Joe P. Harris
- Département de chimieUniversité de MontréalMontréalQuébecH3C 3J7Canada
| | - Luca M. Carrella
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Eva Rentschler
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Ute Resch‐Genger
- Division BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard-Willstätter-Straße 1112489BerlinGermany
| | - Christian Reber
- Département de chimieUniversité de MontréalMontréalQuébecH3C 3J7Canada
| | - Michael Seitz
- Institute of Inorganic ChemistryUniversity of TübingenAuf der Morgenstelle 1872076TübingenGermany
| | - Markus Gerhards
- Department of Chemistry and Research Center OptimasTU KaiserslauternErwin-Schrödinger-Straße67663KaiserslauternGermany
| | - Katja Heinze
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
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14
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Treiling S, Wang C, Förster C, Reichenauer F, Kalmbach J, Boden P, Harris JP, Carrella LM, Rentschler E, Resch‐Genger U, Reber C, Seitz M, Gerhards M, Heinze K. Luminescence and Light‐Driven Energy and Electron Transfer from an Exceptionally Long‐Lived Excited State of a Non‐Innocent Chromium(III) Complex. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909325] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Steffen Treiling
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Cui Wang
- Division BiophotonicsFederal Institute for Materials Research and Testing (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
- Institute of Chemistry and BiochemistryFreie Universität Berlin Takustraße 3 14195 Berlin Germany
| | - Christoph Förster
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Florian Reichenauer
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Jens Kalmbach
- Institute of Inorganic ChemistryUniversity of Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Pit Boden
- Department of Chemistry and Research Center OptimasTU Kaiserslautern Erwin-Schrödinger-Straße 67663 Kaiserslautern Germany
| | - Joe P. Harris
- Département de chimieUniversité de Montréal Montréal Québec H3C 3J7 Canada
| | - Luca M. Carrella
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Eva Rentschler
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Ute Resch‐Genger
- Division BiophotonicsFederal Institute for Materials Research and Testing (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
| | - Christian Reber
- Département de chimieUniversité de Montréal Montréal Québec H3C 3J7 Canada
| | - Michael Seitz
- Institute of Inorganic ChemistryUniversity of Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Markus Gerhards
- Department of Chemistry and Research Center OptimasTU Kaiserslautern Erwin-Schrödinger-Straße 67663 Kaiserslautern Germany
| | - Katja Heinze
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University of Mainz Duesbergweg 10–14 55128 Mainz Germany
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15
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Turner ZR. Bismuth Pyridine Dipyrrolide Complexes: a Transient Bi(II) Species Which Ring Opens Cyclic Ethers. Inorg Chem 2019; 58:14212-14227. [DOI: 10.1021/acs.inorgchem.9b02314] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Zoë R. Turner
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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16
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Katari M, Carmichael D, Jacquemin D, Frison G. Structure of Electronically Reduced N-Donor Bidentate Ligands and Their Heteroleptic Four-Coordinate Zinc Complexes: A Survey of Density Functional Theory Results. Inorg Chem 2019; 58:7169-7179. [PMID: 31117621 DOI: 10.1021/acs.inorgchem.8b03549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of Hartree-Fock exchange in describing the structural changes occurring upon reduction of bipyridine-based ligands and their complexes is investigated within the framework of density functional theory (DFT) calculations. A set of four free ligands in their neutral and radical anionic forms, and two of their zinc complexes in their dicationic and monocationic radical forms, is used to compare a large panel of pure, conventional, and long-range corrected hybrid DFT functionals; coupled cluster single and double calculations are used alongside experimental results as benchmarks. Particular attention has been devoted to the magnitude of the change, upon reduction, of the Δ-parameter, which measures the difference between the Cpy-Cpy and the C-N bond lengths in bipyridine ligand and is known to experimentally correlate with the charge of the ligands. Our results indicate that the structural changes significantly depend on the amount of exact exchange included in the functional. A progressive evolution is observed for the free ligands, whereas two distinct sets of results are obtained for the complexes. Functionals with a small degree of HF exchange, e.g., B3LYP, do not adequately describe geometric changes for the considered species, and, quite surprisingly, the same holds for the CC2 method. The best agreement to experimental and CCSD values is obtained with functionals that include a significant but not excessive part of exact exchange, e.g., CAM-B3LYP, M06-2X, and ωB97X-D. The calculated localization of the added electron after reduction, which depends on the self-interaction error, is used to rationalize these outcomes. Static correlation is also shown to play a role in the accurate description of the electronic structure.
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Affiliation(s)
| | - Duncan Carmichael
- LCM, CNRS, Ecole Polytechnique , IP Paris , F-91128 Palaiseau , France
| | - Denis Jacquemin
- University of Nantes , CNRS, CEISAM (UMR 6230), 2 chemin de la Houssinière , 44322 Nantes , Cedex 03 , France
| | - Gilles Frison
- LCM, CNRS, Ecole Polytechnique , IP Paris , F-91128 Palaiseau , France
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17
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Hakey BM, Darmon JM, Zhang Y, Petersen JL, Milsmann C. Synthesis and Electronic Structure of Neutral Square-Planar High-Spin Iron(II) Complexes Supported by a Dianionic Pincer Ligand. Inorg Chem 2019; 58:1252-1266. [PMID: 30608668 DOI: 10.1021/acs.inorgchem.8b02730] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Two square-planar high-spin FeII complexes bearing a dianionic pyridine dipyrrolate pincer ligand and a diethyl ether or tetrahydrofuran ligand were synthesized and structurally characterized, and their electronic structures were elucidated by a combined spectroscopic and computational approach. In contrast to previous examples, the S = 2 ground states of these square-planar FeII complexes do not require an overall anionic charge of the compounds or incorporation of alkali metal cations. The tetrahydrofuran complex exhibits an equilibrium between four- and five-coordinate species in solution, which was supported by 1H NMR and 57Fe Mössbauer spectroscopy and comparison to a structurally characterized five-coordinate pyridine dipyrrolate iron bis-pyridine adduct. A detailed computational analysis of the electronic structures of the four- and five-coordinate species via density functional theory provides insight into the origins of the unusual ground state configurations for FeII in a square-planar ligand field and explains the associated characteristic spectroscopic parameters.
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Affiliation(s)
- Brett M Hakey
- C. Eugene Bennett Department of Chemistry , West Virginia University , 100 Prospect Street , Morgantown , West Virginia 26506 , United States
| | - Jonathan M Darmon
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Yu Zhang
- C. Eugene Bennett Department of Chemistry , West Virginia University , 100 Prospect Street , Morgantown , West Virginia 26506 , United States
| | - Jeffrey L Petersen
- C. Eugene Bennett Department of Chemistry , West Virginia University , 100 Prospect Street , Morgantown , West Virginia 26506 , United States
| | - Carsten Milsmann
- C. Eugene Bennett Department of Chemistry , West Virginia University , 100 Prospect Street , Morgantown , West Virginia 26506 , United States
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18
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Cvijanović D, Pisk J, Pavlović G, Šišak-Jung D, Matković-Čalogović D, Cindrić M, Agustin D, Vrdoljak V. Discrete mononuclear and dinuclear compounds containing a MoO22+ core and 4-aminobenzhydrazone ligands: synthesis, structure and organic-solvent-free epoxidation activity. NEW J CHEM 2019. [DOI: 10.1039/c8nj04074e] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
New aroylhydrazone molybdenum(vi) complexes have been synthesized, characterized and used as (pre)catalysts for epoxidation of cyclooctene using aqueous TBHP as the oxidant.
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Affiliation(s)
- Danijela Cvijanović
- University of Zagreb
- School of Medicine
- Department of Chemistry and Biochemistry
- 10000 Zagreb
- Croatia
| | - Jana Pisk
- University of Zagreb
- Faculty of Science
- Department of Chemistry
- 10000 Zagreb
- Croatia
| | - Gordana Pavlović
- University of Zagreb
- Faculty of Textile Technology
- 10000 Zagreb
- Croatia
| | | | | | - Marina Cindrić
- University of Zagreb
- Faculty of Science
- Department of Chemistry
- 10000 Zagreb
- Croatia
| | - Dominique Agustin
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4
- France
| | - Višnja Vrdoljak
- University of Zagreb
- Faculty of Science
- Department of Chemistry
- 10000 Zagreb
- Croatia
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19
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Wang SY, Zhou ZH. Molybdenum imidazole citrate and bipyridine homocitrate in different oxidation states – balance between coordinated α-hydroxy and α-alkoxy groups. RSC Adv 2019; 9:519-528. [PMID: 35521591 PMCID: PMC9059298 DOI: 10.1039/c8ra09134j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 12/11/2018] [Indexed: 01/28/2023] Open
Abstract
Oxo and thiomolybdenum(iv/vi) imidazole hydrocitrates K2{MoIV3O4(im)3[MoVIO3(Hcit)]2}·3im·4H2O (1), (Him)2{MoIV3SO3(im)3[MoVIO3(Hcit)]2}·im·6H2O (2), molybdenum(v) bipyridine homocitrate trans-[(MoVO)2O(H2homocit)2(bpy)2]·4H2O (3) and molybdenum(vi) citrate (Et4N)[MoVIO2Cl(H2cit)]·H2O (4) (H4cit = citric acid, H4homocit = homocitric acid, im = imidazole and bpy = 2,2′-bipyridine) with different oxidation states were prepared. 1 and 2 are the coupling products of [MoVIO3(Hcit)]3− anions and incomplete cubane units [MoIV3O4]4+ ([MoIV3SO3]4+) with monodentate imidazoles, respectively, where tridentate citrates coordinate with α-hydroxy, α-carboxy and β-carboxy groups, forming pentanuclear skeleton structures. The molybdenum atoms in 1 and 2 show unusual +4 and +6 valences based on charge balances, theoretical bond valence calculations and Mo XPS spectrum. The coordinated citrates in 1 and 2 are protonated with α-hydroxy groups, while 3 and 4 with higher oxidation states of +5 and +6 are deprotonated with α-alkoxy group even under strong acidic condition, respectively. This shows the relationship between the oxidation state and protonation of the α-alkoxy group in citrate or homocitrate, which is related to the protonation state of homocitrate in FeMo-cofactor of nitrogenase. The homocitrate in 3 chelates to molybdenum(v) with bidentate α-alkoxy and monodentate α-carboxy groups. Molybdenum(vi) citrate 4 is only protonated with coordinated and uncoordinated β-carboxy groups. The solution behaviours of 1 and 2 are discussed based on 1H and 13C NMR spectroscopies and cyclic voltammograms, showing no decomposition of the species. Oxo and thiomolybdenum(iv/vi) citrates, molybdenum(v) homocitrate and molybdenum(vi) citrate were obtained, showing the influence of coordinated α-hydroxy and α-alkoxy groups with different oxidation states.![]()
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Affiliation(s)
- Si-Yuan Wang
- State Key Laboratory for Physical Chemistry of Solid Surfaces
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen
- China
| | - Zhao-Hui Zhou
- State Key Laboratory for Physical Chemistry of Solid Surfaces
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen
- China
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20
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Huh DN, Ziller JW, Evans WJ. Chelate-Free Synthesis of the U(II) Complex, [(C 5H 3(SiMe 3) 2) 3U] 1-, Using Li and Cs Reductants and Comparative Studies of La(II) and Ce(II) Analogs. Inorg Chem 2018; 57:11809-11814. [PMID: 30182717 DOI: 10.1021/acs.inorgchem.8b01966] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
To expand the range of synthetic options for generating complexes of the actinide metals in the +2 oxidation state, reduction of Cp″3U (Cp″ = C5H3(SiMe3)2) and the lanthanide analogs, Cp″3La and Cp″3Ce with lithium in the absence of crown ether and cryptand chelates was explored. In each case, crystallographically characterizable [Li(THF)4][Cp″3M] complexes were obtainable in yields of 70-75% for M = La and Ce and 45-50% for M = U, that is, chelating agents are not necessary to sequester the lithium countercation to form isolable crystalline M(II) products. Reductions using Cs were also explored and X-ray crystallography revealed the formation of an oligomeric structure, [Cp″U(μ-Cp")2Cs(THF)2] n, involving Cp″ ligands that bridge "(Cp″UII)1+" moieties to "[Cp″2Cs(THF)2]1-" units.
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Affiliation(s)
- Daniel N Huh
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Joseph W Ziller
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - William J Evans
- Department of Chemistry , University of California , Irvine , California 92697 , United States
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21
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Yadav S, Singh A, Rashid N, Ghotia M, Roy TK, Ingole PP, Ray S, Mobin SM, Dash C. Phosphine-Free Bis(Pyrrolyl)pyridine Based NNN-Pincer Palladium(II) Complexes as Efficient Catalysts for Suzuki-Miyaura Cross-Coupling Reactions of Aryl Bromides in Aqueous Medium. ChemistrySelect 2018. [DOI: 10.1002/slct.201801647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Seema Yadav
- Department of Chemistry; School of Chemical Sciences and Pharmacy; Central University of Rajasthan, Bandarsindri; India
| | - Ajeet Singh
- Department of Chemistry; Indian Institute of Technology (IIT) Indore, Simrol; Khandwa Road Indore - 453552 India
| | - Nusrat Rashid
- Department of Chemistry; Indian Institute of Technology, Delhi, Hauz Khas; New Delhi 110016 India
| | - Maheshwari Ghotia
- Department of Chemistry; School of Chemical Sciences and Pharmacy; Central University of Rajasthan, Bandarsindri; India
| | - Tapta Kanchan Roy
- Department of Chemistry and Chemical Sciences; Central University of Jammu; Jammu-180001 India
| | - Pravin P. Ingole
- Department of Chemistry; Indian Institute of Technology, Delhi, Hauz Khas; New Delhi 110016 India
| | - Sriparna Ray
- Department of Chemistry; School of Basic Sciences; Manipal University; Jaipur-303007 India
| | - Shaikh M. Mobin
- Department of Chemistry; Indian Institute of Technology (IIT) Indore, Simrol; Khandwa Road Indore - 453552 India
| | - Chandrakanta Dash
- Department of Chemistry; School of Chemical Sciences and Pharmacy; Central University of Rajasthan, Bandarsindri; India
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22
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Zhang Y, Lee TS, Petersen JL, Milsmann C. A Zirconium Photosensitizer with a Long-Lived Excited State: Mechanistic Insight into Photoinduced Single-Electron Transfer. J Am Chem Soc 2018; 140:5934-5947. [PMID: 29671586 DOI: 10.1021/jacs.8b00742] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Time-resolved emission spectroscopy for the luminescent zirconium complex Zr(MePDP)2 (MePDP = 2,6-bis(5-methyl-3-phenyl-1 H-pyrrol-2-yl)pyridine) revealed a long-lived excited state with a lifetime τ = 325 ± 10 μs. Computational studies using time-dependent density functional theory were conducted to identify the nature of the luminescent excited state as a mixed triplet intraligand/ligand-to-metal charge-transfer state. Stern-Volmer experiments showed a strong dependence of the quenching rate on the redox potential of the quencher indicating photoinduced single-electron transfer (SET) as the quenching pathway. Mechanistic investigations of the photocatalytic homocoupling of benzyl bromide allowed the detection of organic radical intermediates during turnover and provided further evidence for SET mediated by Zr(MePDP)2. Isolation of the one-electron-reduced form of the photosensitizer, [Zr(MePDP)2]-, enabled studies of its electronic structure by a combination of experimental and computational techniques and confirmed its role as a strong reductant. Additionally, the role of the benzimidazolium hydride derivatives as two-electron sacrificial reductants during photoredox catalysis was investigated. In combination, the results presented in this report establish a detailed mechanistic picture of a photoredox catalytic reaction promoted by an earth-abundant early transition metal photosensitizer.
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Affiliation(s)
- Yu Zhang
- C. Eugene Bennett Department of Chemistry , West Virginia University , Morgantown , West Virginia 26506 , United States
| | - Tia S Lee
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Jeffrey L Petersen
- C. Eugene Bennett Department of Chemistry , West Virginia University , Morgantown , West Virginia 26506 , United States
| | - Carsten Milsmann
- C. Eugene Bennett Department of Chemistry , West Virginia University , Morgantown , West Virginia 26506 , United States
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