1
|
Takeda H, Irimajiri M, Mizutani T, Nozawa S, Matsuura Y, Kurosu M, Ishitani O. Photocatalytic CO 2 Reduction Using Mixed Catalytic Systems Comprising an Iron Cation with Bulky Phenanthroline Ligands. Inorg Chem 2024; 63:7343-7355. [PMID: 38598607 DOI: 10.1021/acs.inorgchem.4c00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
This study reports on efficient photocatalytic CO2 reduction reactions using mixed catalytic systems of an Fe ion source and various 1,10-phenanthroline derivatives (R1R2p) as ligands in the presence of triethanolamine (TEOA). As the relatively bulky substituents at positions 2 and 9 of R1R2p weakened the ability to coordinate to the Fe ion, the Fe ion formed TEOA complexes. The free R1R2p accepted an electron from the reduced photosensitizer through proton-coupled electron transfer (PCET) using protons of TEOA dissolved in a CH3CN solution in a CO2 atmosphere as the initial step of the catalytic cycle. Although the mixed system of the nonsubstituted 1,10-phenanthroline generates a stable tris(phenanthroline)-Fe(II) complex in solution, this complex could not function as a CO2 reduction catalyst. The mechanism in which R1R2p interacts with the Fe ion after PCET was proposed for this efficient photocatalytic CO2 reduction. The proposed photocatalytic system using the 2,9-di-sec-butyl-phenanthroline ligand could produce CO with high efficiency (quantum yield of 8.2%) combined with a dinuclear Cu(I) complex as a photosensitizer.
Collapse
Affiliation(s)
- Hiroyuki Takeda
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin, Kiryu, Gunma 376-8515, Japan
| | - Mina Irimajiri
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Toshihide Mizutani
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Shunsuke Nozawa
- High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Yuna Matsuura
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin, Kiryu, Gunma 376-8515, Japan
| | - Masao Kurosu
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin, Kiryu, Gunma 376-8515, Japan
| | - Osamu Ishitani
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8526, Japan
| |
Collapse
|
2
|
Benner F, La Droitte L, Cador O, Le Guennic B, Demir S. Magnetic hysteresis and large coercivity in bisbenzimidazole radical-bridged dilanthanide complexes. Chem Sci 2023; 14:5577-5592. [PMID: 37265712 PMCID: PMC10231311 DOI: 10.1039/d3sc01562a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 04/10/2023] [Indexed: 06/03/2023] Open
Abstract
A judicious combination of radical ligands innate to diffuse spin orbitals with paramagnetic metal ions elicits strong magnetic exchange coupling which leads to properties important for future technologies. This metal-radical approach aids in effective magnetic communication of especially lanthanide ions as their 4f orbitals are contracted and not readily accessible. Notably, a high spin density on the donor atoms of the radical is required for strong coupling. Such molecules are extremely rare owing to high reactivity rendering their isolation challenging. Herein, we present two unprecedented series of bisbenzimidazole-based dilanthanide complexes [(Cp*2Ln)2(μ-Bbim)] (1-Ln = Gd, Tb, Dy, Bbim = 2,2'-bisbenzimidazole) and [K(crypt-222)][(Cp*2Ln)2(μ-Bbim˙)] -(2-Ln = Gd, Tb, Dy), where the latter contains the first Bbim3-˙ radical matched with any paramagnetic metal ion. The magnetic exchange constant for 2-Gd of J = -1.96(2) cm-1 suggests strong antiferromagnetic Gd-radical coupling, whereas the lanthanides in 1-Gd are essentially uncoupled. Ab initio calculations on 2-Tb and 2-Dy uncovered coupling strengths of -4.8 and -1.8 cm-1. 1-Dy features open hysteresis loops with a coercive field of Hc of 0.11 T where the single-molecule magnetism can be attributed to the single-ion effect due to lack of coupling. Excitingly, pairing the effective magnetic coupling with the strong magnetic anisotropy of Dy results in magnetic hysteresis with a blocking temperature TB of 5.5 K and coercive field HC of 0.54 T, ranking 2-Dy as the second best dinuclear single-molecule magnet containing an organic radical bridge. A Bbim4- species is formed electrochemically hinting at the accessibility of Bbim-based redox-active materials.
Collapse
Affiliation(s)
- Florian Benner
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Léo La Droitte
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Olivier Cador
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Selvan Demir
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| |
Collapse
|
3
|
Yan H, Wu B, Wei J, Zhang WX. Insight into the Ligand-to-Ligand Charge-Transfer Process in Rare-Earth-Metal Diradical Complexes. Inorg Chem 2023; 62:8052-8057. [PMID: 37184543 DOI: 10.1021/acs.inorgchem.3c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
While a ligand-to-ligand charge-transfer (LLCT) process is an important way to understand the interactions between metal-bridged radicals for late-transition-metal complexes, there is little clear and evident observation of the LLCT process for rare-earth-metal complexes. In this work, rare-earth-metal diradical complexes supported by diazabutadiene (DAD) ligands [(DAD)2RE(BH4)] [RE = Yb (1), Sm (2)] were synthesized and studied. The coordination geometries of 1 and 2 are different due to the different ionic radii. Reduction of 1 or 2 generated monoradical complexes, with one of their DAD radical anions being reduced. In all of the complexes, Sm and Yb remain at the 3+ valence state. In their UV-vis spectra, the LLCT transition of 1 could be clearly observed, but complex 2 did not show the same transition. These results could be related to the geometric structures of the complexes as well as exchange coupling between diradicals, thus clearly expanding the model for late-transition-metal-bridged diradicals to rare-earth systems experimentally.
Collapse
Affiliation(s)
- Haihan Yan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Botao Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
4
|
Murakami HA, Uslan C, Haase AA, Koehn JT, Vieira AP, Gaebler DJ, Hagan J, Beuning CN, Proschogo N, Levina A, Lay PA, Crans DC. Vanadium Chloro-Substituted Schiff Base Catecholate Complexes are Reducible, Lipophilic, Water Stable, and Have Anticancer Activities. Inorg Chem 2022; 61:20757-20773. [PMID: 36519680 DOI: 10.1021/acs.inorgchem.2c02557] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A hydrophobic Schiff base catecholate vanadium complex was recently discovered to have anticancer properties superior to cisplatin and suited for intratumoral administration. This [VO(HSHED)(DTB)] complex, where HSHED is N-(salicylideneaminato)-N'-(2-hydroxyethyl)-1,2-ethanediamine and the non-innocent catecholato ligand is di-t-butylcatecholato (DTB), has higher stability compared to simpler catecholato complexes. Three new chloro-substituted Schiff base complexes of vanadium(V) with substituted catecholates as co-ligands were synthesized for comparison with their non-chlorinated Schiff base vanadium complexes, and their properties were characterized. Up to four geometric isomers for each complex were identified in organic solvents using 51V and 1H NMR spectroscopies. Spectroscopy was used to characterize the structure of the major isomer in solution and to demonstrate that the observed isomers are exchanged in solution. All three chloro-substituted Schiff base vanadium(V) complexes with substituted catecholates were also characterized by UV-vis spectroscopy, mass spectrometry, and electrochemistry. Upon testing in human glioblastoma multiforme (T98g) cells as an in vitro model of brain gliomas, the most sterically hindered, hydrophobic, and stable compound [t1/2 (298 K) = 15 min in cell medium] was better than the two other complexes (IC50 = 4.1 ± 0.5 μM DTB, 34 ± 7 μM 3-MeCat, and 19 ± 2 μM Cat). Furthermore, upon aging, the complexes formed less toxic decomposition products (IC50 = 9 ± 1 μM DTB, 18 ± 3 μM 3-MeCat, and 8.1 ± 0.6 μM Cat). The vanadium complexes with the chloro-substituted Schiff base were more hydrophobic, more hydrolytically stable, more easily reduced compared to their corresponding parent counterparts, and the most sterically hindered complex of this series is only the second non-innocent vanadium Schiff base complex with a potent in vitro anticancer activity that is an order of magnitude more potent than cisplatin under the same conditions.
Collapse
Affiliation(s)
- Heide A Murakami
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Canan Uslan
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Allison A Haase
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Jordan T Koehn
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Adriana Pires Vieira
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - D Jackson Gaebler
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - John Hagan
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Cheryle N Beuning
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Nicholas Proschogo
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Aviva Levina
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Peter A Lay
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia.,Sydney Analytical, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Debbie C Crans
- Chemistry Department, Colorado State University, Fort Collins, Colorado 80523, United States.,Cell and Molecular Biology Program, Colorado State University, Fort Collins, Colorado 80523, United States
| |
Collapse
|
5
|
Danchovski Y, Rasheev H, Stoyanova R, Tadjer A. Molecular Engineering of Quinone-Based Nickel Complexes and Polymers for All-Organic Li-Ion Batteries. Molecules 2022; 27:molecules27206805. [PMID: 36296395 PMCID: PMC9608464 DOI: 10.3390/molecules27206805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/01/2022] [Accepted: 10/07/2022] [Indexed: 11/16/2022] Open
Abstract
All-organic Li-ion batteries appear to be a sustainable and safer alternative to the currently-used Li-ion batteries but their application is still limited due to the lack of organic compounds with high redox potentials toward Li+/Li0. Herein, we report a computational design of nickel complexes and coordination polymers that have redox potentials spanning the full voltage range: from the highest, 4.7 V, to the lowest, 0.4 V. The complexes and polymers are modeled by binding low- and high-oxidized Ni ions (i.e., Ni(II) and Ni(IV)) to redox-active para-benzoquinone molecules substituted with carboxyl- and cyano-groups. It is found that both the nickel ions and the quinone-derived ligands are redox-active upon lithiation. The type of Ni coordination also has a bearing on the redox potentials. By combining the complex of Ni(IV) with 2-carboxylato-5-cyano-1,4-benzoquinones as a cathode and Ni(II)-2,5-dicarboxylato-3,6-dicyano-1,4-benzoquinone coordination polymer as an anode, all-organic Li-ion batteries could be assembled, operating at an average voltage exceeding 3.0 V and delivering a capacity of more than 300 mAh/g.
Collapse
Affiliation(s)
- Yanislav Danchovski
- Faculty of Chemistry and Pharmacy, University of Sofia, 1164 Sofia, Bulgaria
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Hristo Rasheev
- Faculty of Chemistry and Pharmacy, University of Sofia, 1164 Sofia, Bulgaria
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
- Correspondence: (H.R.); (R.S.); (A.T.)
| | - Radostina Stoyanova
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
- Correspondence: (H.R.); (R.S.); (A.T.)
| | - Alia Tadjer
- Faculty of Chemistry and Pharmacy, University of Sofia, 1164 Sofia, Bulgaria
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
- Correspondence: (H.R.); (R.S.); (A.T.)
| |
Collapse
|
6
|
Das A, Schleinitz J, Karmazin L, Vincent B, Le Breton N, Rogez G, Guenet A, Choua S, Grimaud L, Desage‐El Murr M. A Single Bioinspired Hexameric Nickel Catechol–Alloxazine Catalyst Combines Metal and Radical Mechanisms for Alkene Hydrosilylation. Chemistry 2022; 28:e202200596. [DOI: 10.1002/chem.202200596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Agnideep Das
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Jules Schleinitz
- Laboratoire des biomolécules LBM, Chemistry Department École normale supérieure PSL University Sorbonne Université, CNRS 75005 Paris France
| | - Lydia Karmazin
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Bruno Vincent
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Nolwenn Le Breton
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg Université de Strasbourg, CNRS, UMR 7504 67000 Strasbourg France
| | - Aurélie Guenet
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Sylvie Choua
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Laurence Grimaud
- Laboratoire des biomolécules LBM, Chemistry Department École normale supérieure PSL University Sorbonne Université, CNRS 75005 Paris France
| | | |
Collapse
|
7
|
Emelina TB, Mirochnik AG. Thermoluminescent Tb(III) and Dy(III) complexes with redox-active ligands: experimental and theoretical study. LUMINESCENCE 2022; 37:1369-1375. [PMID: 35705217 DOI: 10.1002/bio.4309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/20/2022] [Accepted: 06/12/2022] [Indexed: 11/09/2022]
Abstract
Thermoluminescence and persistent luminescent materials with unique delayed emission have attracted much attention and exhibit great promise in optical information storage. In this manuscript, to reveal the thermoluminescence mechanism, a combined experimental and theoretical study of ternary Ln(NO3 )2 Acac(Phen)2 complexes, where Ln is Tb(III), Dy(III), Eu(III), Acac is acetylacetonate anion, and Phen is 1,10-phenanthroline, was carried out. The terbium and dysprosium complexes had thermoluminescence properties, while the europium complex did not. A thermoluminescence mechanism is proposed: the powerful double π-conjugate phenanthroline system appearance upon photoexcitation, the peculiarities of frontier orbitals, the abnormally small highest occupied molecular orbital-lowest unoccupied molecular orbital gap, and the geometrical changes in the terbium and dysprosium complexes led us to suggest that phenanthroline molecules serve as 'chemical' electron traps. Therefore, we succeeded in 'freezing' and storing the excited state of complexes I and II indefinitely. The obtained thermoluminescent materials with 'chemical' traps of electrons are capable of storing the energy from incident photons and exhibit a great opportunity in optical information storage and anticounterfeiting applications.
Collapse
Affiliation(s)
- Tatyana B Emelina
- Institute of Chemistry, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia
| | - Anatolii G Mirochnik
- Institute of Chemistry, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia
| |
Collapse
|
8
|
Pashanova KI, Poddel'sky AI, Piskunov AV. Complexes of “late” transition metals of the 3d row based on functionalized o-iminobenzoquinone type ligands: Interrelation of molecular and electronic structure, magnetic behaviour. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214399] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
9
|
Kapurwan S, Gupta A, Mondal A, Konar S. Halo‐Substituted Blatter Radicals and Their Role in Modulating Magnetic Interaction in Metal Complexes: A Combined Experimental and Theoretical Study. ChemistrySelect 2022. [DOI: 10.1002/slct.202104536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sandhya Kapurwan
- Department of Chemistry Indian Institute of Science Education and Research Bhopal Bhopal By-pass Road, Bhauri Madhya Pradesh India- 462066
| | - Arindam Gupta
- Department of Chemistry Indian Institute of Science Education and Research Bhopal Bhopal By-pass Road, Bhauri Madhya Pradesh India- 462066
| | - Arpan Mondal
- Department of Chemistry Indian Institute of Science Education and Research Bhopal Bhopal By-pass Road, Bhauri Madhya Pradesh India- 462066
| | - Sanjit Konar
- Department of Chemistry Indian Institute of Science Education and Research Bhopal Bhopal By-pass Road, Bhauri Madhya Pradesh India- 462066
| |
Collapse
|
10
|
Henke WC, Stiel JP, Day VW, Blakemore JD. Evidence for Charge Delocalization in Diazafluorene Ligands Supporting Low-Valent [Cp*Rh] Complexes. Chemistry 2022; 28:e202103970. [PMID: 35006643 PMCID: PMC8857064 DOI: 10.1002/chem.202103970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Indexed: 12/14/2022]
Abstract
Ligands based upon the 4,5-diazafluorene core are an important class of emerging ligands in organometallic chemistry, but the structure and electronic properties of these ligands have received less attention than they deserve. Here, we show that 9,9'-dimethyl-4,5-diazafluorene (Me2 daf) can stabilize low-valent complexes through charge delocalization into its conjugated π-system. Using a new platform of [Cp*Rh] complexes with three accessible formal oxidation states (+III, +II, and +I), we show that the methylation in Me2 daf is protective, blocking Brønsted acid-base chemistry commonly encountered with other daf-based ligands. Electronic absorption spectroscopy and single-crystal X-ray diffraction analysis of a family of eleven new compounds, including the unusual Cp*Rh(Me2 daf), reveal features consistent with charge delocalization driven by π-backbonding into the LUMO of Me2 daf, reminiscent of behavior displayed by the workhorse 2,2'-bipyridyl ligand. Taken together with spectrochemical data demonstrating clean conversion between oxidation states, our findings show that 9,9'-dialkylated daf-type ligands are promising building blocks for applications in reductive chemistry and catalysis.
Collapse
Affiliation(s)
- Wade C. Henke
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Jonah P. Stiel
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| |
Collapse
|
11
|
Suhr S, Walter R, Beerhues J, Albold U, Sarkar B. Rhodium Diamidobenzene Complexes: A Tale of Different Substituents on the Diamidobenzene Ligand. Chem Sci 2022; 13:10532-10545. [PMID: 36277629 PMCID: PMC9473529 DOI: 10.1039/d2sc03227a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
Diamidobenzene ligands are a prominent class of redox-active ligands owing to their electron reservoir behaviour, as well as the possibility of tuning the steric and the electronic properties of such ligands through the substituents on the N-atoms of the ligands. In this contribution, we present Rh(iii) complexes with four differently substituted diamidobenzene ligands. By using a combination of crystallography, NMR spectroscopy, electrochemistry, UV-vis-NIR/EPR spectroelectrochemistry, and quantum chemical calculations we show that the substituents on the ligands have a profound influence on the bonding, donor, electrochemical and spectroscopic properties of the Rh complexes. We present, for the first time, design strategies for the isolation of mononuclear Rh(ii) metallates whose redox potentials span across more than 850 mV. These Rh(ii) metallates undergo typical metalloradical reactivity such as activation of O2 and C–Cl bond activations. Additionally, we also show that the substituents on the ligands dictate the one versus two electron nature of the oxidation steps of the Rh complexes. Furthermore, the oxidative reactivity of the metal complexes with a [CH3]+ source leads to the isolation of a unprecedented, homobimetallic, heterovalent complex featuring a novel π-bonded rhodio-o-diiminoquionone. Our results thus reveal several new potentials of the diamidobenzene ligand class in organometallic reactivity and small molecule activation with potential relevance for catalysis. Diamidobenzene ligands are versatile platforms in organometallic Rh-chemistry. They allow the isolation of tunable mononuclear ate-complexes, and the formation of a unprecedented homobimetallic, heterovalent complex.![]()
Collapse
Affiliation(s)
- Simon Suhr
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Walter
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Julia Beerhues
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Uta Albold
- Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstr. 34-36 14195 Berlin Germany
| | - Biprajit Sarkar
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| |
Collapse
|
12
|
Benner F, Demir S. Isolation of the elusive bisbenzimidazole Bbim 3−˙ radical anion and its employment in a metal complex. Chem Sci 2022; 13:5818-5829. [PMID: 35685798 PMCID: PMC9132035 DOI: 10.1039/d1sc07245e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/05/2022] [Indexed: 11/28/2022] Open
Abstract
The discovery of singular organic radical ligands is a formidable challenge due to high reactivity arising from the unpaired electron. Matching radical ligands with metal ions to engender magnetic coupling is crucial for eliciting preeminent physical properties such as conductivity and magnetism that are crucial for future technologies. The metal-radical approach is especially important for the lanthanide ions exhibiting deeply buried 4f-orbitals. The radicals must possess a high spin density on the donor atoms to promote strong coupling. Combining diamagnetic 89Y (I = 1/2) with organic radicals allows for invaluable insight into the electronic structure and spin-density distribution. This approach is hitherto underutilized, possibly owing to the challenging synthesis and purification of such molecules. Herein, evidence of an unprecedented bisbenzimidazole radical anion (Bbim3−˙) along with its metalation in the form of an yttrium complex, [K(crypt-222)][(Cp*2Y)2(μ-Bbim˙)] is provided. Access of Bbim3−˙ was feasible through double-coordination to the Lewis acidic metal ion and subsequent one-electron reduction, which is remarkable as Bbim2− was explicitly stated to be redox-inactive in closed-shell complexes. Two molecules containing Bbim2− (1) and Bbim3−˙ (2), respectively, were thoroughly investigated by X-ray crystallography, NMR and UV/Vis spectroscopy. Electrochemical studies unfolded a quasi-reversible feature and emphasize the role of the metal centre for the Bbim redox-activity as neither the free ligand nor the Bbim2− complex led to analogous CV results. Excitingly, a strong delocalization of the electron density through the Bbim3−˙ ligand was revealed via temperature-dependent EPR spectroscopy and confirmed through DFT calculations and magnetometry, rendering Bbim3−˙ an ideal candidate for single-molecule magnet design. The long sought-after bisbenzimidazole radical was isolated through complexation to two rare earth metallocenes followed by reduction, and analysed through crystallography, VT EPR spectroscopy, electrochemistry, magnetometry, and DFT computations.![]()
Collapse
Affiliation(s)
- Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
| |
Collapse
|
13
|
Shanmugam M, Kumar P, Sen A, Rajaraman G. An Unusual Mixed Valent Cobalt Dimer as a Catalyst for Anti-Markovnikov Hydrophophination of Alkynes. Inorg Chem Front 2022. [DOI: 10.1039/d2qi00112h] [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
The reaction of [Co(PMe3)4] (1) with a redox-active NNN pincer ligand (L1) led us to isolate a unique binuclear cobalt complex ([(PMe3)2CoII(L13-)CoI(PMe3)3] (2)) anchored by a three electron reduced L1...
Collapse
|
14
|
Junker P, Rey Planells A, Espinosa Ferao A, Streubel R. Analysis of Non-innocence of Phosphaquinodimethane Ligands when Charge and Aromaticity Come into Play. Chemistry 2021; 27:9350-9359. [PMID: 33811689 PMCID: PMC8362198 DOI: 10.1002/chem.202100420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Indexed: 11/11/2022]
Abstract
Several phosphaquinodimethanes and their M(CO)5 complexes (M=Cr, Mo, W) and model derivatives have been theoretically investigated regarding the quest of non-innocence. Computed structural and electronic properties of the P-Me/NH2 substituted phosphaquinodimethanes and tungsten complexes revealed an interesting non-innocent ligand behaviour for the radical anion complexes with distonic ion character and a strong rearomatization of the middle phenyl ring. The latter was further probed taking also geometric aromaticity (HOMA) and quinoid distortion parameters (HOMQc) into account, as well as NICS(1). Furthermore, the effect of the P-substitution was investigated for real (or plausible) complexes and their free ligands focusing on the resulting aromaticity at the middle phenyl ring and vertical one-electron redox processes. The best picture of ligand engagement in redox changes was provided by representing NICS(1) values versus HOMA and the new geometric distortion parameter HOMQc8.
Collapse
Affiliation(s)
- Philip Junker
- Institut für Anorganische ChemieRheinische Friedrich-Wilhelms-Universität BonnGerhardt-Domagk-Straße 153121BonnGermany
| | - Alicia Rey Planells
- Departamento de Química OrgánicaFacultad de QuímicaUniversidad de MurciaCampus de Espinardo30100MurciaSpain
| | - Arturo Espinosa Ferao
- Departamento de Química OrgánicaFacultad de QuímicaUniversidad de MurciaCampus de Espinardo30100MurciaSpain
| | - Rainer Streubel
- Institut für Anorganische ChemieRheinische Friedrich-Wilhelms-Universität BonnGerhardt-Domagk-Straße 153121BonnGermany
| |
Collapse
|
15
|
Choi J, Kim SH, Lee Y. Axial Redox Tuning at a Tetragonal Cobalt Center. Inorg Chem 2021; 60:5647-5659. [PMID: 33788551 DOI: 10.1021/acs.inorgchem.0c03676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Square pyramidal cobalt complexes were prepared to study their multielectron redox properties. To build a stable redox-active cobalt complex, the combination of a tridentate acriPNP (acriPNP- = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9H-acridin-10-ide) ligand with a bidentate ligand, such as 2,2'-bipyridine, 2-(o-phenyl)pyridine, biphenylene, and their analogues, was employed. In a cobalt complex having a tetragonal structure, the dx2-y2 orbital possesses an antibonding character and must remain empty for its structural integrity, while the dz2 orbital acts as a redox-active frontier molecular orbital (FMO). Tuning the redox potential of the Co(II/I) couple was successfully achieved by introducing a different axial donor. The reduction of Co(II) to Co(I) occurs at -2.6 V for a neutral donor but shifts to -3.4 V for an anionic donor. Since the redox-active dz2 orbital is close in energy to other ligand-based orbitals, multielectron redox activity is also observed. Electrochemical measurements indicate three reversible redox events within a window of -3.0-0.0 V vs Fc/Fc+ in tetrahydrofuran (THF). These redox processes are fully reversible for over 100 cycles, reflecting the electrochemical stability of these cobalt complexes. Surprisingly, the oxidation potential of the acriPNP ligand varies dramatically from +0.15 to -2.4 V, which is probably due to the cobalt contribution on the amido-based molecular orbital. The electronic structure of the cobalt complexes was examined structurally, spectroscopically, and theoretically.
Collapse
Affiliation(s)
- Jonghoon Choi
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Sun Hee Kim
- Western Seoul Center, Korea Basic Science Institute, Seoul 03759, Republic of Korea
| | - Yunho Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
16
|
Salomón FF, Vega NC, Jurado JP, Morán Vieyra FE, Tirado M, Comedi D, Campoy-Quiles M, Cattaneo M, Katz NE. Heteroleptic Ruthenium(II) Complexes with 2,2'-Bipyridines Having Carbonitriles as Anchoring Groups for ZnO Surfaces: Syntheses, Physicochemical Properties, and Applications in Organic Solar Cells. Inorg Chem 2021; 60:5660-5672. [PMID: 33821633 DOI: 10.1021/acs.inorgchem.0c03691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heteroleptic ruthenium (II) complexes were used for sensitizing ZnO surfaces in organic solar cells (OSCs) as mediators with photoactive layers. The complexes [Ru(4,4'-X2-bpy)(Mebpy-CN)2]2+ (with X = -CH3, -OCH3 and -N(CH3)2; bpy = 2,2'-bipyridine; Mebpy-CN = 4-methyl-2,2'-bipyridine-4'-carbonitrile) were synthesized and studied by analytical and spectroscopical techniques. Spectroscopic, photophysical, and electrochemical properties were tuned by changing the electron-donating ability of the -X substituents at the 4,4'-positions of the bpy ring and rationalized by quantum mechanical calculations. These complexes were attached through nitrile groups to ZnO as interfacial layer in an OSC device with a PBDB-T:ITIC photoactive layer. This modified inorganic electron transport layer generates enhancement in photoconversion of the solar cells, reaching up to a 23% increase with respect to the unsensitized OSCs. The introduction of these dyes suppresses some degradative reactions of the nonfullerene acceptor due to the photocatalytic activity of zinc oxide, which was maintained stable for about 11 months. Improving OSC efficiencies and stabilities can thus be achieved by a judicious combination of new inorganic and organic materials.
Collapse
Affiliation(s)
- Fernando F Salomón
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
| | - Nadia C Vega
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - José Piers Jurado
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, España
| | - Faustino E Morán Vieyra
- INBIONATEC (CONICET-UNSE), Laboratorio de Cinética y Fotoquímica, Universidad Nacional de Santiago del Estero, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - Mónica Tirado
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - David Comedi
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - Mariano Campoy-Quiles
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, España
| | - Mauricio Cattaneo
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
| | - Néstor E Katz
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
| |
Collapse
|
17
|
Kumari M, Bera SK, Blickle S, Kaim W, Lahiri GK. The Indigo Isomer Epindolidione as a Redox‐Active Bridging Ligand for Diruthenium Complexes. Chemistry 2021; 27:5461-5469. [DOI: 10.1002/chem.202004747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/09/2020] [Indexed: 01/29/2023]
Affiliation(s)
- Maya Kumari
- Department of Chemistry Indian Institute of Technology Bombay Powai, Mumbai 400076 India
| | - Sudip Kumar Bera
- Department of Chemistry Indian Institute of Technology Bombay Powai, Mumbai 400076 India
| | - Svenja Blickle
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry Indian Institute of Technology Bombay Powai, Mumbai 400076 India
| |
Collapse
|
18
|
Zhong JS, Yu Y, Shi Z, Ye KY. An electrochemical perspective on the roles of ligands in the merger of transition-metal catalysis and electrochemistry. Org Chem Front 2021. [DOI: 10.1039/d0qo01227k] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A perspective on the roles of ligands in transition-metal catalysis under electrochemical conditions is provided.
Collapse
Affiliation(s)
- Jun-Song Zhong
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- College of Chemistry
- Fuzhou University
- Fuzhou 350108
- China
| | - Yi Yu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- College of Chemistry
- Fuzhou University
- Fuzhou 350108
- China
| | - Zhaojiang Shi
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- College of Chemistry
- Fuzhou University
- Fuzhou 350108
- China
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- College of Chemistry
- Fuzhou University
- Fuzhou 350108
- China
| |
Collapse
|
19
|
Ou YP, Zhang J, Hu Y, Yin J, Chi C, Liu SH. Oxidized divinyl oligoacene-bridged diruthenium complexes: bridged localized radical characters and reduced aromaticity in bridge cores. Dalton Trans 2020; 49:16877-16886. [PMID: 33180078 DOI: 10.1039/d0dt02883e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A series of bimetallic ruthenium vinyl complexes 1-5 bridged by oligoacenes were synthesized and characterized in this study. Comparative cyclic voltammetry results from 1-5 indicated that the first oxidation potential decreased gradually with the extension of conjugate ligands. Upon oxidation to singly oxidized species 1+-5+, rather small ν(CO) changes in the infrared (IR) spectra and the characteristic bands of metal-to-ligand charge transfer absorptions in the near IR (NIR) region predicted via time-dependent DFT calculations suggested that strong bridged ligands participate in redox processes. NIR absorptions were not observed in complexes 4+ and 5+ possibly because of instability in their twisted and noncoplanar geometry. Electron paramagnetic resonance results and spin density distribution demonstrated that the bridged localized degrees of 1+-5+ successively increased with the extension of oligoacene from benzene to tetracene. Further comparative analysis of neutral molecules and monocations to the aromaticity and π-electron density of bridge cores indicated a step-by-step transformation process from an aromatic to quinoidal radical upon oxidation.
Collapse
Affiliation(s)
- Ya-Ping Ou
- Key Laboratory of Functional Metal-Organic Compounds of Hunan Province, Key Laboratory of Functional Organometallic Materials of Hunan Province College, College of Chemistry and Material Science, Hengyang Normal University, Hengyang, Hunan 421008, P. R. China
| | | | | | | | | | | |
Collapse
|
20
|
Billups JR, Fokakis ZN, Creutz SE. Octahedral Iron Complexes of Pyrazine(diimine) Pincers: Ligand Electronic Effects and Protonation. Inorg Chem 2020; 59:15228-15239. [DOI: 10.1021/acs.inorgchem.0c02211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jaylan R. Billups
- Department of Chemistry, Mississippi State University, Starkville Mississippi 39762, United States
| | - Zoe N. Fokakis
- Department of Chemistry, Mississippi State University, Starkville Mississippi 39762, United States
| | - Sidney E. Creutz
- Department of Chemistry, Mississippi State University, Starkville Mississippi 39762, United States
| |
Collapse
|
21
|
Henke WC, Hopkins JA, Anderson ML, Stiel JP, Day VW, Blakemore JD. 4,5-Diazafluorene and 9,9'-Dimethyl-4,5-Diazafluorene as Ligands Supporting Redox-Active Mn and Ru Complexes. MOLECULES (BASEL, SWITZERLAND) 2020; 25:molecules25143189. [PMID: 32668660 PMCID: PMC7396985 DOI: 10.3390/molecules25143189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/03/2020] [Accepted: 07/10/2020] [Indexed: 11/16/2022]
Abstract
4,5-diazafluorene (daf) and 9,9’-dimethyl-4,5-diazafluorene (Me2daf) are structurally similar to the important ligand 2,2’-bipyridine (bpy), but significantly less is known about the redox and spectroscopic properties of metal complexes containing Me2daf as a ligand than those containing bpy. New complexes Mn(CO)3Br(daf) (2), Mn(CO)3Br(Me2daf) (3), and [Ru(Me2daf)3](PF6)2 (5) have been prepared and fully characterized to understand the influence of the Me2daf framework on their chemical and electrochemical properties. Structural data for 2, 3, and 5 from single-crystal X-ray diffraction analysis reveal a distinctive widening of the daf and Me2daf chelate angles in comparison to the analogous Mn(CO)3(bpy)Br (1) and [Ru(bpy)3]2+ (4) complexes. Electronic absorption data for these complexes confirm the electronic similarity of daf, Me2daf, and bpy, as spectra are dominated in each case by metal-to-ligand charge transfer bands in the visible region. However, the electrochemical properties of 2, 3, and 5 reveal that the redox-active Me2daf framework in 3 and 5 undergoes reduction at a slightly more negative potential than that of bpy in 1 and 4. Taken together, the results indicate that Me2daf could be useful for preparation of a variety of new redox-active compounds, as it retains the useful redox-active nature of bpy but lacks the acidic, benzylic C–H bonds that can induce secondary reactivity in complexes bearing daf.
Collapse
|
22
|
Bauer S, Záliš S, Fiedler J, Ringenberg MR, Kaim W. Oxidation State Assignments in the Organoplatinum One‐Electron Redox Series [(N
^
N)PtMes
2
]
n
,
n
= +,0, –,2‐. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Sonja Bauer
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Stanislav Záliš
- J. Heyrovský Institute of Physical Chemistry The Czech Academy of Sciences Dolejškova 3 18223 Prague Czech Republic
| | - Jan Fiedler
- J. Heyrovský Institute of Physical Chemistry The Czech Academy of Sciences Dolejškova 3 18223 Prague Czech Republic
| | - Mark R. Ringenberg
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
| |
Collapse
|
23
|
Mashima K. Redox-Active α-Diimine Complexes of Early Transition Metals: From Bonding to Catalysis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200056] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| |
Collapse
|
24
|
Yang Y, Hu H, Guo Y, Xia A, Xu J, Zhang X. Supramolecular Polymeric Radicals: Highly Promoted Formation and Stabilization of Naphthalenediimide Radical Anions. Macromol Rapid Commun 2020; 41:e2000080. [DOI: 10.1002/marc.202000080] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/17/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Yuchong Yang
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry Tsinghua University Beijing 100084 China
| | - Hao Hu
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry Tsinghua University Beijing 100084 China
| | - Yuanyuan Guo
- The Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS) Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
| | - Andong Xia
- The Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS) Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
| | - Jiang‐Fei Xu
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry Tsinghua University Beijing 100084 China
| | - Xi Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry Tsinghua University Beijing 100084 China
- State Key Lab of Supramolecular Structure and Materials Jilin University Changchun 130012 China
| |
Collapse
|
25
|
Affiliation(s)
- Wolfgang Beck
- Department Chemie Ludwig‐Maximilians‐Universität München Butenandtstr. 5‐13 (D) 81377 München Germany
| | - Karlheinz Sünkel
- Department Chemie Ludwig‐Maximilians‐Universität München Butenandtstr. 5‐13 (D) 81377 München Germany
| |
Collapse
|
26
|
Nandhini R, Vijayan P, Venkatachalam G. Palladium(II) complexes containing sterically bulky O, N donor ligands: Synthesis, characterization and catalytic activity in the Suzuki-Miyaura and Sonogashira coupling reactions. J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2019.121080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
27
|
Tang B, Zhao J, Xu JF, Zhang X. Tuning the stability of organic radicals: from covalent approaches to non-covalent approaches. Chem Sci 2020; 11:1192-1204. [PMID: 34123243 PMCID: PMC8148027 DOI: 10.1039/c9sc06143f] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 12/26/2019] [Indexed: 12/22/2022] Open
Abstract
Organic radicals are important species with single electrons. Because of their open-shell structure, they are widely used in functional materials, such as spin probes, magnetic materials and optoelectronic materials. Owing to the high reactivity of single electrons, they often serve as a key intermediate in organic synthesis. Therefore, tuning the stability of radicals is crucial for their functions. Herein, we summarize covalent and non-covalent approaches to tune the stability of organic radicals through steric effects and tuning the delocalization of spin density. Covalent approaches can tune the stability of radicals effectively and non-covalent approaches benefit from dynamicity and reversibility. It is anticipated that the further development of covalent and non-covalent approaches, as well as the interplay between them, may push the fields forward by enriching new radical materials and radical mediated reactions.
Collapse
Affiliation(s)
- Bohan Tang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Jiantao Zhao
- Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Jiang-Fei Xu
- Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Xi Zhang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University Beijing 100084 China
| |
Collapse
|
28
|
Zuleta EC, Goenaga GA, Zawodzinski TA, Elder T, Bozell JJ. Deactivation of Co-Schiff base catalysts in the oxidation of para-substituted lignin models for the production of benzoquinones. Catal Sci Technol 2020. [DOI: 10.1039/c9cy02040c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Those features which enhance the reactivity of Co-Schiff base oxidation catalysts can also contribute to their demise.
Collapse
Affiliation(s)
- Ernesto C. Zuleta
- Center for Renewable Carbon
- University of Tennessee
- Knoxville
- USA
- Bredesen Center for Interdisciplinary Research and Education
| | - Gabriel A. Goenaga
- Department of Chemical and Biomolecular Engineering
- University of Tennessee
- Knoxville
- USA
| | - Thomas A. Zawodzinski
- Bredesen Center for Interdisciplinary Research and Education
- Knoxville
- USA
- Department of Chemical and Biomolecular Engineering
- University of Tennessee
| | | | - Joseph J. Bozell
- Center for Renewable Carbon
- University of Tennessee
- Knoxville
- USA
- Bredesen Center for Interdisciplinary Research and Education
| |
Collapse
|
29
|
Isoda K, Takahashi H, Mutoh Y, Hoshino N, Akutagawa T. One-dimensional single-helix coordination polymer self-assembled by a crown-ether appended-N-heteroacene radical anion. Dalton Trans 2019; 48:13125-13129. [PMID: 31386724 DOI: 10.1039/c9dt02797a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A crown-ether appended N-heteroacene 1 was reduced in the presence of NaBPh4 to the radical anion 2 by accepting one electron transferred from both the cathode and BPh4- as a reductant. The obtained radical anion 2 can function as a radical anion ligand to bridge two sodium ions to self-assemble into one-dimensional helical coordination polymers.
Collapse
Affiliation(s)
- Kyosuke Isoda
- Program in Advanced Materials Science, Faculty of Engineering and Design, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Japan. and Division of Advanced Materials Science, Graduate School of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Japan and Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Japan
| | - Hinako Takahashi
- Division of Advanced Materials Science, Graduate School of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Japan
| | - Yuichiro Mutoh
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Tokyo 162-8601, Japan
| | - Norihisa Hoshino
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Tomoyuki Akutagawa
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
| |
Collapse
|
30
|
Aldrich KE, Fales BS, Singh AK, Staples RJ, Levine BG, McCracken J, Smith MR, Odom AL. Electronic and Structural Comparisons between Iron(II/III) and Ruthenium(II/III) Imide Analogs. Inorg Chem 2019; 58:11699-11715. [DOI: 10.1021/acs.inorgchem.9b01672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kelly E. Aldrich
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - B. Scott Fales
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Amrendra K. Singh
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Richard J. Staples
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Benjamin G. Levine
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - John McCracken
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Milton R. Smith
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Aaron L. Odom
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
31
|
Rajpurohit J, Shanmugam M. The molecular and electronic structure of an unusual cobalt NNO pincer ligand complex. Dalton Trans 2019; 48:7378-7387. [PMID: 30949637 DOI: 10.1039/c9dt00056a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of two equivalents of [Co(PMe3)4] (1) with one equivalent of a neutral NNO pincer ligand (L1) led to the formation of purple-coloured single crystals. The crystal structure determination reveals the molecular structure as a cobalt dimer [Co2(L1)(PMe3)5], which is solved in the triclinic P1[combining macron] space group. Although this species appears to have a formal zero oxidation state on cobalt ions, careful analysis of the structural parameters of the L1 reveals that the NNO ligand is reduced by three electrons; this observation has rarely been reported in the literature. Therefore, herein, more accurate description of the molecular formula [(PMe3)2CoII(η4-L13-)CoI(PMe3)3] (2) was proposed. In 2, we observed an unusual η3-π-allyl-type binding mode of the pyridine ring carbon atoms of the L13- ligand with the cobalt ion. X-ray photoelectron spectroscopy not only reveals the presence of the mixed valent cobalt ion within 2 but also unambiguously discloses the spin state of these metal ions (Co(i) diamagnetic (low-spin) and Co(ii) paramagnetic (high-spin)). The proposed electronic structure is consistent with the magnetic moment measured at room temperature. The electronic structure of 2 was further supported by the Q-band EPR measurements performed on polycrystalline sample of 2 at 5.0 K, and the presence of two independent S = ½ states was revealed. This has been qualitatively rationalized based on the super-exchange coupling pathway observed in 2. The NMR studies performed for 2 (C6D6 solvent) evidently showed that the solid-state structure of 2 was maintained in solution.
Collapse
Affiliation(s)
- Jitendrasingh Rajpurohit
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, Maharashtra, India.
| | - Maheswaran Shanmugam
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, Maharashtra, India.
| |
Collapse
|
32
|
Abstract
Redox-active unsaturated chelate ligands can be realised with different ring sizes of the resulting metallacycles. An overview is presented, starting from an exposition of non-innocent behaviour and chelate effects. A systematic approach is used to describe the most familiar situation, the metal complexes of 1,4-hetero-1,3-dienes in established forms (e.g. o-quinone, α-dithiolene, and α-diimine ligands) and with less common combinations of O, S, and N heteroatoms. The different steric and electronic conditions in six-membered chelate ring systems derived from the β-diketonate structure will be discussed with examples of substituted and π extended ligands, including 9-oxidophenalenyl, formazanate, and anions derived from indigo or 9,10-anthraquinone. Four-membered chelate rings existing in at least two ligand-based oxidation states are available through steric and electronic stabilisation in amidinate or triazenide complexes. Three-membered and seven-membered chelate ring situations are discussed briefly as further alternatives.
Collapse
Affiliation(s)
- Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
| |
Collapse
|
33
|
Sagadevan A, Pampana VKK, Hwang KC. Copper Photoredox Catalyzed A3’ Coupling of Arylamines, Terminal Alkynes, and Alcohols through a Hydrogen Atom Transfer Process. Angew Chem Int Ed Engl 2019; 58:3838-3842. [DOI: 10.1002/anie.201813315] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/24/2018] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Kuo Chu Hwang
- Department of ChemistryNational Tsing Hua University Hsinchu Taiwan, R.O.C
| |
Collapse
|
34
|
Saeedi R, Safaei E, Lee YI, Lužnik J. Oxidation of sulfides including DBT using a new vanadyl complex of a non-innocent o
-aminophenol benzoxazole based ligand. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.4781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Roonak Saeedi
- Institute for Advanced Studies in Basic Sciences (IASBS); 45137-66731 Zanjan Iran
| | - Elham Safaei
- Department of Chemistry, College of Sciences; Shiraz University; Shiraz 71454 Iran
| | - Yong-Ill Lee
- Department of Chemistry; Changwon National University; Changwon 641-773 South Korea
| | - Janez Lužnik
- J. Stefan Institute and University of Ljubljana, Faculty of Mathematics and Physics; Jamova 39, SI-1000 Ljubljana Slovenia SI-1000 Ljubljana Slovenia
| |
Collapse
|
35
|
New Oxidovanadium(IV) Complexes with 2,2′-bipyridine and 1,10-phenathroline Ligands: Synthesis, Structure and High Catalytic Activity in Oxidations of Alkanes and Alcohols with Peroxides. Catalysts 2019. [DOI: 10.3390/catal9030217] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reactions of [VCl3(thf)3] or VBr3 with 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) in a 1:1 molar ratio in air under solventothermal conditions has afforded polymeric oxidovanadium(IV) four complexes 1–4 of a general formula [VO(L)X2]n (L = bpy, phen and X = Cl, Br). Monomeric complex [VO(DMF)(phen)Br2] (4a) has been obtained by the treatment of compound 4 with DMF. The complexes were characterized by IR spectroscopy and elemental analysis. The crystal structures of 3 and 4a were determined by an X-ray diffraction (XRD) analysis. The {VOBr2(bpy)} fragments in 3 form infinite chains due to the V = O…V interactions. The vanadium atom has a distorted octahedral coordination environment. Complexes 1–4 have been tested as catalysts in the homogeneous oxidation of alkanes (to produce corresponding alkyl hydroperoxides which can be easily reduced to alcohols by PPh3) and alcohols (to corresponding ketones) with H2O2 or tert-butyl hydroperoxide in MeCN. Compound 1 exhibited the highest activity. The mechanism of alkane oxidation was established using experimental selectivity and kinetic data and theoretical DFT calculations. The mechanism is of the Fenton type involving the generation of HO• radicals.
Collapse
|
36
|
Sagadevan A, Pampana VKK, Hwang KC. Copper Photoredox Catalyzed A3’ Coupling of Arylamines, Terminal Alkynes, and Alcohols through a Hydrogen Atom Transfer Process. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813315] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | - Kuo Chu Hwang
- Department of ChemistryNational Tsing Hua University Hsinchu Taiwan, R.O.C
| |
Collapse
|
37
|
A computational study of electrocatalytic CO2 reduction by Mn(I) complexes: Role of bipyridine substituents. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.11.210] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
38
|
Schröder J, Himmel D, Kratzert D, Radtke V, Richert S, Weber S, Böttcher T. Isolation of a stable pyridine radical anion. Chem Commun (Camb) 2019; 55:1322-1325. [DOI: 10.1039/c8cc09700c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
For almost 150 years, pyridine radical anions have been described as elusive transient species that cannot be isolated due to dimerization and/or subsequent decomposition reactions. In this work the first example of a stable pyridine radical anion is presented.
Collapse
Affiliation(s)
- Jan Schröder
- Institut für Anorganische und Analytische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Daniel Himmel
- Institut für Anorganische und Analytische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Daniel Kratzert
- Institut für Anorganische und Analytische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Valentin Radtke
- Institut für Anorganische und Analytische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Sabine Richert
- Institut für Physikalische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Stefan Weber
- Institut für Physikalische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| | - Tobias Böttcher
- Institut für Anorganische und Analytische Chemie
- Universität Freiburg
- 79104 Freiburg
- Germany
| |
Collapse
|
39
|
Patra SC, Saha Roy A, Banerjee S, Banerjee A, Das Saha K, Bhadra R, Pramanik K, Ghosh P. Palladium(ii) and platinum(ii) complexes of glyoxalbis(N-aryl)osazone: molecular and electronic structures, anti-microbial activities and DNA-binding study. NEW J CHEM 2019. [DOI: 10.1039/c9nj00223e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A new family of palladium(ii) and platinum(ii) complexes of redox non-innocent osazone ligands that exhibit moderate antileishmanial activity were isolated.
Collapse
Affiliation(s)
- Sarat Chandra Patra
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
- Department of Chemistry
| | - Amit Saha Roy
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
- Department of Chemistry
| | - Saswati Banerjee
- Cancer Biology & Inflammatory Disorder
- Indian Institute of Chemical Biology
- Kolkata 700032
- India
| | - Ananya Banerjee
- Department of Chemistry
- Bijaygarh Jyotish Roy College
- Kolkata-700032
- India
| | - Krishna Das Saha
- Cancer Biology & Inflammatory Disorder
- Indian Institute of Chemical Biology
- Kolkata 700032
- India
| | - Ranjan Bhadra
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
| | | | - Prasanta Ghosh
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
| |
Collapse
|
40
|
Starikova AA, Minkin VI. Adducts of transition metal complexes with redox-active ligands: the structure and spin-state-switching rearrangements. RUSSIAN CHEMICAL REVIEWS 2018. [DOI: 10.1070/rcr4837] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
41
|
Rath SP, Sengupta D, Ghosh P, Bhattacharjee R, Chakraborty M, Samanta S, Datta A, Goswami S. Effects of Ancillary Ligands on Redox and Chemical Properties of Ruthenium Coordinated Azoaromatic Pincer. Inorg Chem 2018; 57:11995-12009. [PMID: 30207466 DOI: 10.1021/acs.inorgchem.8b01558] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In this work, the effect of the electronically different ancillary ligands on the overall properties of the RuIIL moiety (L = 2,6-bis(phenylazo)pyridine) in heteroleptic complexes of general formula [RuLQCl]0/+ was investigated. Four different ancillary ligands (Q) with different electronic effects were used to prepare the heteroleptic compounds from the precursor complex, [RuL(CH3CN)Cl2] (1); Q = pcp: 2-(4-chloro-phenylazo)pyridine (strong π-acceptor), [2]+; bpy: 2,2'-bipyridyl (moderate π-acceptor), [3]+; acac-: acetylacetonate (strong σ-donor), 4; and DTBCat2-: 3,5-di- tert-butyl catecholate (strong π-donor), 5. The complexes [2]+, [3]+, 4, and 5 were fully characterized and structurally identified. The electronic structures of these complexes along with their redox partners were elucidated by using a host of physical measurements: nuclear magnetic resonance, cyclic voltammetry, electronic paramagnetic resonance, UV-vis-NIR spectroscopy, and density functional theory. The studies revealed significant effects of the coligands on azo bond lengths of the RuL moiety and their redox behavior. Aerobic alcohol oxidation reactions using these Ru complexes as catalysts were scrutinized. It was found that the catalytic efficiency is primarily controlled by the electronic effect of the coligand. Accordingly, the complex [2]+ (containing a strong π-acceptor coligand, pcp) brings about oxidation efficiently, producing 86% of benzaldehyde. In comparison, however, the complexes 4 and 5 (containing electron donating coligand) furnished only 15-20% of benzaldehyde under identical reaction conditions. Investigations of the reaction mechanism suggest that an unstable Ru-H species is formed, which is transformed to a Ru-hydrazo intermediate by H-walking as reported by Hall et al. ( J. Am. Chem. Soc., 2015, 137, 12330). Aerial O2 regenerates the catalyst via oxidation of the hydrazo intermediate.
Collapse
Affiliation(s)
- Santi Prasad Rath
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Debabrata Sengupta
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Pradip Ghosh
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Rameswar Bhattacharjee
- Department of Spectroscopy , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Mou Chakraborty
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Subhas Samanta
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Ayan Datta
- Department of Spectroscopy , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| | - Sreebrata Goswami
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032 , India
| |
Collapse
|
42
|
Mews NM, Hörner G, Schubert H, Berkefeld A. Tuning of Thiyl/Thiolate Complex Near-Infrared Chromophores of Platinum through Geometrical Constraints. Inorg Chem 2018; 57:9670-9682. [PMID: 29561154 DOI: 10.1021/acs.inorgchem.8b00122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The chemistry of radical-ligand complexes of the transition metals has developed into a vibrant field of research that spans from fundamental studies on the relationship between the chemical and electronic structures to applications in catalysis and functional materials chemistry. In general, fine-tuning of the relevant properties relies on an increasingly diversifying pool of radical-proligand structures. Surprisingly, the variability of the conformational freedom and the number of distinct bonding modes supported by many radical proligands is limited. This work reports on the angular constraints and relative geometric alignment of metal and ligand orbitals as key parameters that render a series of chemically similar thiyl/thiolate complexes of platinum(II) electronically and spectroscopically distinct. The use of conformational flexible thiophenols as primary ligand scaffolds is essential to establishing a defined radical-ligand [(areneS)2PtII]•+ core whose electronic structure is modulated by a series of auxiliary coligands at platinum.
Collapse
Affiliation(s)
- Nicole M Mews
- Institut für Anorganische Chemie , Eberhard Karls Universität Tübingen , Auf der Morgenstelle 18 , 72076 Tübingen , Germany
| | - Gerald Hörner
- Institut für Chemie, Quantenchemie und Bioanorganische Chemie , Technische Universität (TU) Berlin , Straße des 17 Juni 135 , 10623 Berlin , Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie , Eberhard Karls Universität Tübingen , Auf der Morgenstelle 18 , 72076 Tübingen , Germany
| | - Andreas Berkefeld
- Institut für Anorganische Chemie , Eberhard Karls Universität Tübingen , Auf der Morgenstelle 18 , 72076 Tübingen , Germany
| |
Collapse
|
43
|
Shiga T, Kumamaru R, Newton GN, Oshio H. Cobalt complexes with redox-active anthraquinone-type ligands. Dalton Trans 2018; 47:7804-7811. [PMID: 29850706 DOI: 10.1039/c8dt00586a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three anthraquinone-type multidentate ligands, HL1-3 (HL = 2-R-1H-anthra[1,2-d]imidazole-6,11-dione; HL1: R = (2-pyridyl), HL2; R = (4,6-dimethyl-2-pyridyl), HL3; R = (6-methoxy-2-pyridyl)), were prepared, and their complexation behaviour was investigated. Three bis-chelate cobalt complexes with the formula [CoII(L1-3)2]·n(solv.) (1, 2, and 3 for HL1, HL2, and HL3, respectively), in which the ligands adopted tridentate binding modes, were synthesized and structurally characterized by single-crystal X-ray analyses. Electrochemical studies of 1-3 in CH2Cl2 reveal three reversible redox waves, assigned to ligand and cobalt-centred processes. Additional complexes were obtained in which HL1 adopted a bidentate binding mode, stabilising the mono-chelate [CoII(HL1)(NO3)2(DMF)2] (4) species and tris-chelate [CoIII(L1)3] (5) complex in which the cobalt ion was in its 3+ state. The electrochemical properties of complex 5 were investigated in DMF, and the Co(ii)/Co(iii) redox couple was found to be negatively shifted compared to that of complex 1, while the ligand-based processes became irreversible. Tridentate chelation is found to stabilise the anthraquinone ligands and unlocks their redox multi-stability.
Collapse
Affiliation(s)
- Takuya Shiga
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba 305-8571, Japan.
| | | | | | | |
Collapse
|
44
|
Mondal S, Schwederski B, Frey W, Fiedler J, Záliš S, Kaim W. At the Borderline between Metal–Metal Mixed Valency and a Radical Bridge Situation: Four Charge States of a Diruthenium Complex with a Redox-Active Bis(mer-tridentate) Ligand. Inorg Chem 2018. [DOI: 10.1021/acs.inorgchem.8b00173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Sudipta Mondal
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Brigitte Schwederski
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Wolfgang Frey
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Jan Fiedler
- The Czech Academy of Sciences, J. Heyrovský Institute of Physical Chemistry, Dolejškova 3, 18223 Prague, Czech Republic
| | - Stanislav Záliš
- The Czech Academy of Sciences, J. Heyrovský Institute of Physical Chemistry, Dolejškova 3, 18223 Prague, Czech Republic
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| |
Collapse
|
45
|
Hazari AS, Paretzki A, Fiedler J, Zalis S, Kaim W, Lahiri GK. Different manifestations of enhanced π-acceptor ligation at every redox level of [Os(9-OP)L 2] n, n = 2+, +, 0, - (9-OP - = 9-oxidophenalenone and L = bpy or pap). Dalton Trans 2018; 45:18241-18251. [PMID: 27801461 DOI: 10.1039/c6dt03764j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The title complexes were isolated as structurally characterised compounds [OsII(9-OP)L2]ClO4, L = 2,2'-bipyridine (bpy) or 2-phenylazopyridine (pap), and were compared with ruthenium analogues. A reversible one-electron oxidation and up to three reduction processes were observed by voltammetry (CV, DPV) and spectroelectrochemistry (UV-vis-NIR, partially EPR). Supporting calculations (DFT, TD-DFT) were used to assess the oxidation state combinations of the different redox active ligands and of the metal, revealing the effects of Os versus Ru exchange and of bpy versus pap acceptor ligation. Several unexpected consequences of these variations were observed for members of the new osmium-containing redox series. Remarkably, the EPR results exhibit a clear dichotomy between the complex ion [OsIII(9-OP-)(bpy)2]2+ and the radical species [OsII(9-OP˙)(pap)2]2+, which has not been similarly observed for the analogous [RuIII(9-OP-)L2]2+ systems. This difference, unprecedented for 5dn systems, is attributed to the superior stabilisation of the OsII state by the strongly π-accepting pap ligands. The reduced forms [OsII(9-OP-)(pap˙-)(pap)] and [OsII(9-OP-)(pap˙-)2]- exhibit strong inter-ligand interactions, leading to spin isomers and electron hopping.
Collapse
Affiliation(s)
- Arijit Singha Hazari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Alexa Paretzki
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
| | - Jan Fiedler
- J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-18223 Prague, Czech Republic
| | - Stanislav Zalis
- J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-18223 Prague, Czech Republic
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| |
Collapse
|
46
|
Lionetti D, Day VW, Lassalle-Kaiser B, Blakemore JD. Multiple binding modes of an unconjugated bis(pyridine) ligand stabilize low-valent [Cp*Rh] complexes. Chem Commun (Camb) 2018; 54:1694-1697. [DOI: 10.1039/c7cc09164h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
An unconjugated bis(pyridine) ligand enables sequential one-electron reductions of a [Cp*Rh] complex, revealing the ligand's ability to stabilize low-valent species.
Collapse
Affiliation(s)
| | - Victor W. Day
- Department of Chemistry
- University of Kansas
- Lawrence
- USA
| | | | | |
Collapse
|
47
|
Fomenko IS, Gushchin AL, Shul’pina LS, Ikonnikov NS, Abramov PA, Romashev NF, Poryvaev AS, Sheveleva AM, Bogomyakov AS, Shmelev NY, Fedin MV, Shul’pin GB, Sokolov MN. New oxidovanadium(iv) complex with a BIAN ligand: synthesis, structure, redox properties and catalytic activity. NEW J CHEM 2018. [DOI: 10.1039/c8nj03358g] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The combination of a new oxidovanadium(iv) complex1with pyrazine-2-carboxylic acid (PCA; a cocatalyst) affords a catalytic system for the efficient oxidation of saturated hydrocarbons.
Collapse
Affiliation(s)
- Iakov S. Fomenko
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
| | - Artem L. Gushchin
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- 630090 Novosibirsk
| | - Lidia S. Shul’pina
- Nesmeyanov Institute of Organoelement Compounds
- Russian Academy of Sciences
- Moscow 119991
- Russia
| | - Nikolay S. Ikonnikov
- Nesmeyanov Institute of Organoelement Compounds
- Russian Academy of Sciences
- Moscow 119991
- Russia
| | - Pavel A. Abramov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
| | - Nikolay F. Romashev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- 630090 Novosibirsk
| | - Artem S. Poryvaev
- Novosibirsk State University
- 630090 Novosibirsk
- Russia
- International Tomography Center, Siberian Branch of Russian Academy of Sciences
- 630090 Novosibirsk
| | - Alena M. Sheveleva
- Novosibirsk State University
- 630090 Novosibirsk
- Russia
- International Tomography Center, Siberian Branch of Russian Academy of Sciences
- 630090 Novosibirsk
| | - Artem S. Bogomyakov
- International Tomography Center, Siberian Branch of Russian Academy of Sciences
- 630090 Novosibirsk
- Russia
| | - Nikita Y. Shmelev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- 630090 Novosibirsk
| | - Matvey V. Fedin
- International Tomography Center, Siberian Branch of Russian Academy of Sciences
- 630090 Novosibirsk
- Russia
| | - Georgiy B. Shul’pin
- Department of Dynamics of Chemical and Biologicl Processes, Semenov Institute of Chemical Physics, Russian Academy of Sciences
- Moscow 119991
- Russia
- Chair of Chemistry and Physics, Plekhanov Russian University of Economics
- Moscow 117997
| | - Maxim N. Sokolov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- 630090 Novosibirsk
| |
Collapse
|
48
|
Interacting metal and ligand based open shell systems: Challenges for experiment and theory. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.12.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
49
|
Nishiyama H, Ikeda H, Saito T, Kriegel B, Tsurugi H, Arnold J, Mashima K. Structural and Electronic Noninnocence of α-Diimine Ligands on Niobium for Reductive C-Cl Bond Activation and Catalytic Radical Addition Reactions. J Am Chem Soc 2017; 139:6494-6505. [PMID: 28409626 DOI: 10.1021/jacs.7b02710] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A d0 niobium(V) complex, NbCl3(α-diimine) (1a), supported by a dianionic redox-active N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1,3-butadiene (α-diimine) ligand (ene-diamido ligand) served as a catalyst for radical addition reactions of CCl4 to α-olefins and cyclic alkenes, selectively affording 1:1 radical addition products in a regioselective manner. During the catalytic reaction, the α-diimine ligand smoothly released and stored an electron to control the oxidation state of the niobium center by changing between an η4-(σ2,π) coordination mode with a folded MN2C2 metallacycle and a κ2-(N,N') coordination mode with a planar MN2C2 metallacycle. Kinetic studies of the catalytic reaction elucidated the reaction order in the catalytic cycle: the radical addition reaction rate obeyed first-order kinetics that were dependent on the concentrations of the catalyst, styrene, and CCl4, while a saturation effect was observed at a high CCl4 concentration. In the presence of excess amounts of styrene, styrene coordinated in an η2-olefinic manner to the niobium center to decrease the reaction rate. No observation of oligomers or polymers of styrene and high stereoselectivity for the radical addition reaction of CCl4 to cyclopentene suggested that the C-C bond formation proceeded inside the coordination sphere of niobium, which was in good accordance with the negative entropy value of the radical addition reaction. Furthermore, reaction of 1a with (bromomethyl)cyclopropane confirmed that both the C-Br bond activation and formation proceeded on the α-diimine-coordinated niobium center during transformation of the cyclopropylmethyl radical to a homoallyl radical. With regard to the reaction mechanism, we detected and isolated NbCl4(α-diimine) (6a) as a transient one-electron oxidized species of 1a during reductive cleavage of the C-X bonds; in addition, the monoanionic α-diimine ligand of 6a adopted a monoanionic canonical form with selective one-electron oxidation of the dianionic ene-diamido form of the ligand in 1a.
Collapse
Affiliation(s)
- Haruka Nishiyama
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| | - Hideaki Ikeda
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| | - Teruhiko Saito
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| | - Benjamin Kriegel
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| | - John Arnold
- Department of Chemistry, University of California , Berkeley, California 94720-1460, United States
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka, 5608531, Japan
| |
Collapse
|
50
|
Duan L, Jia Y, Li X, Li Y, Hu H, Li J, Cui C. Synthesis, Characterization, and Reversible Multielectron Redox Properties of a Biradical Yttrium Complex Containing Bis(2‐isopropylaminophenyl)amide. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201601457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lili Duan
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research Institution Nankai University 300071 Tianjin China
| | - Yi‐Bo Jia
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research Institution Nankai University 300071 Tianjin China
| | - Xiao‐Gen Li
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research Institution Nankai University 300071 Tianjin China
| | - Yue‐Ming Li
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research Institution Nankai University 300071 Tianjin China
| | - Hongfan Hu
- State Key Laboratory of Elemento‐Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering Nankai University 300071 Tianjin China
| | - Jianfeng Li
- State Key Laboratory of Elemento‐Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering Nankai University 300071 Tianjin China
| | - Chunming Cui
- State Key Laboratory of Elemento‐Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering Nankai University 300071 Tianjin China
| |
Collapse
|