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Sun H, Liu X, Li Y, Zhang F, Huang X, Sun C, Huang F. Mechanistic insights of electrocatalytic CO 2 reduction by Mn complexes: synergistic effects of the ligands. Dalton Trans 2024; 53:1663-1672. [PMID: 38168800 DOI: 10.1039/d3dt03453d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The electrocatalytic mechanisms of CO2 reduction catalyzed by pyridine-oxazoline (pyrox)-based Mn catalysts were investigated by DFT calculations. In-depth comparative analyses of pyrox-based and bipyridine-based Mn complexes were carried out. C-OH cleavage is the rate-determining step for both the protonation-first path and the reduction-first path. The free energy of CO2 activation (ΔG1) and the electrons donated by CO ligands in this step are effective descriptors in regulating the C-OH cleavage barrier. The reduction of carboxylate complex 6 (E6) is the potential-determining step for the reduction-first path. Meanwhile, for the protonation-first path, the initial generation (E2) or the regeneration (E8) of active catalyst might be potential-determining. Hirshfeld charge and orbital contribution analysis indicate that E6 is definitely based on the heterocyclic ligand and E2 is related to both the heterocyclic ligand and three CO ligands. Therefore, replacement of the CO ligand by a stronger electron donating ligand can effectively boost the catalytic activity of CO2 reduction without increasing the overpotential in the reduction-first path. This hypothesis is supported by the mechanism calculations of the Mn complex in which the axial CO ligand is replaced by a pyridine or PMe3.
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Affiliation(s)
- Haitao Sun
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Xueqing Liu
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Yafeng Li
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Fang Zhang
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Xiuxiu Huang
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Chuanzhi Sun
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
| | - Fang Huang
- Department of Assets and Laboratory Management, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
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2
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Singh KK, Gerke CS, Saund SS, Zito AM, Siegler MA, Thoi VS. CO 2 Activation with Manganese Tricarbonyl Complexes through an H-Atom Responsive Benzimidazole Ligand. Chemistry 2023; 29:e202300796. [PMID: 37519094 DOI: 10.1002/chem.202300796] [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: 03/11/2023] [Revised: 07/20/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
Herein, we report the synthesis and characterization of two manganese tricarbonyl complexes, MnI (HL)(CO)3 Br (1 a-Br) and MnI (MeL)(CO)3 Br (1 b-Br) (where HL=2-(2'-pyridyl)benzimidazole; MeL=1-methyl-2-(2'-pyridy)benzimidazole) and assayed their electrocatalytic properties for CO2 reduction. A redox-active pyridine benzimidazole ancillary ligand in complex 1 a-Br displayed unique hydrogen atom transfer ability to facilitate electrocatalytic CO2 conversion at a markedly lower reduction potential than that observed for 1 b-Br. Notably, a one-electron reduction of 1 a-Br yields a structurally characterized H-bonded binuclear Mn(I) adduct (2 a') rather than the typically observed Mn(0)-Mn(0) dimer, suggesting a novel method for CO2 activation. Combining advanced electrochemical, spectroscopic, and single crystal X-ray diffraction techniques, we demonstrate the use of an H-atom responsive ligand may reveal an alternative, low-energy pathway for CO2 activation by an earth-abundant metal complex catalyst.
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Affiliation(s)
- Kundan K Singh
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Carter S Gerke
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Simran S Saund
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Alessandra M Zito
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - V Sara Thoi
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, United States
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3
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Cohen KY, Nedd DG, Evans R, Bocarsly AB. Mechanistic insights into CO 2 conversion to CO using cyano manganese complexes. Dalton Trans 2023. [PMID: 37183860 DOI: 10.1039/d3dt00891f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Without the use of a photosensitizer, [Mn(bpy)(CO)3(CN)] (MnCN) can photochemically form [Mn(bpy)(CO)3]-, the active species for CO2 reduction. While cases of the axial X-ligand dissociating upon irradiation of fac-[M(N-N)(CO)3X] complexes (M = Mn or Re; N-N = bipyridine (bpy) ligand; X = halogen or pseudohalogen) are well documented, the axial cyanide ligand is retained when either [Mn(bpy)(CO)3(CN)] or [Mn(mesbpy)(CO)3(CN)], MnCN(mesbpy), are irradiated anaerobically. Infrared and UV-vis spectroscopies indicate the formation of [Mn(bpy)(CO)2(MeCN)(CN)] (s-MnCN) as the primary product during the irradiation of MnCN. An in-depth analysis of the photochemical mechanism for the formation of [Mn(bpy)(CO)3]- from MnCN is presented. MnCN(mesbpy) is too sterically hindered to undergo the same photochemical mechanism as MnCN. However, MnCN(mesbpy) is found to be electrocatalytically active for CO2 reduction to CO. Thus providing an interesting distinction between photochemical and electrochemical charge transfer.
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Affiliation(s)
- Kailyn Y Cohen
- Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey, USA.
| | - Delaan G Nedd
- Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey, USA.
| | - Rebecca Evans
- Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey, USA.
| | - Andrew B Bocarsly
- Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey, USA.
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Singh R, Bains AK, Kundu A, Jain H, Yadav S, Dey D, Adhikari D. Mechanistic Elucidation of an Alcohol Oxidation Reaction Promoted by a Nickel Azophenolate Complex. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Affiliation(s)
- Rahul Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Amreen K. Bains
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Abhishek Kundu
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Harshit Jain
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Sudha Yadav
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Dhananjay Dey
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
| | - Debashis Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar 140306, India
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Phipps CA, Hofsommer DT, Zirilli CD, Duff BG, Mashuta MS, Buchanan RM, Grapperhaus CA. Metal-Ligand Cooperativity Promotes Reversible Capture of Dilute CO 2 as a Zn(II)-Methylcarbonate. Inorg Chem 2023; 62:2751-2759. [PMID: 36715745 DOI: 10.1021/acs.inorgchem.2c03868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In this study, a series of thiosemicarbazonato-hydrazinatopyridine metal complexes were evaluated as CO2 capture agents. The complexes incorporate a non-coordinating, basic hydrazinatopyridine nitrogen in close proximity to a Lewis acidic metal ion allowing for metal-ligand cooperativity. The coordination of various metal ions with (diacetyl-2-(4-methyl-thiosemicarbazone)-3-(2-hydrazinopyridine) (H2L1) yielded ML1 (M = Ni(II), Pd(II)), ML1(CH3OH) (M = Cu(II), Zn(II)), and [ML1(PPh3)2]BF4 (M = Co(III)) complexes. The ML1(CH3OH) complexes reversibly capture CO2 with equilibrium constants of 88 ± 9 and 6900 ± 180 for Cu(II) and Zn(II), respectively. Ligand effects were evaluated with Zn(II) through variation of the 4-methyl-thiosemicarbazone with 4-ethyl (H2L2), 4-phenethyl (H2L3), and 4-benzyl (H2L4) derivatives. The equilibrium constant for CO2 capture increased to 11,700 ± 300, 15,000 ± 400, and 35,000 ± 200 for ZnL2(MeOH), ZnL3(MeOH), and ZnL4(MeOH), respectively. Quantification of ligand basicity and metal ion Lewis acidity shows that changes in CO2 capture affinity are largely associated with ligand basicity upon substitution of Cu(II) with Zn(II), while variation of the thiosemicarbazone ligand enhances CO2 affinity by tuning the metal ion Lewis acidity. Overall, the Zn(II) complexes effectively capture CO2 from dilute sources with up to 90%, 86%, and 65% CO2 capture efficiency from 400, 1000, and 2500 ppm CO2 streams.
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Affiliation(s)
- Christine A Phipps
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Dillon T Hofsommer
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Calian D Zirilli
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Bailee G Duff
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Mark S Mashuta
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Robert M Buchanan
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
| | - Craig A Grapperhaus
- Department of Chemistry, University of Louisville, 2320 S. Brook St, Louisville, Kentucky 40292, United States
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6
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Florian J, Cole JM. Analyzing Structure-Activity Variations for Mn-Carbonyl Complexes in the Reduction of CO 2 to CO. Inorg Chem 2023; 62:318-335. [PMID: 36541860 PMCID: PMC9832541 DOI: 10.1021/acs.inorgchem.2c03391] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Contemporary electrocatalysts for the reduction of CO2 often suffer from low stability, activity, and selectivity, or a combination thereof. Mn-carbonyl complexes represent a promising class of molecular electrocatalysts for the reduction of CO2 to CO as they are able to promote this reaction at relatively mild overpotentials, whereby rare-earth metals are not required. The electronic and geometric structure of the reaction center of these molecular electrocatalysts is precisely known and can be tuned via ligand modifications. However, ligand characteristics that are required to achieve high catalytic turnover at minimal overpotential remain unclear. We consider 55 Mn-carbonyl complexes, which have previously been synthesized and characterized experimentally. Four intermediates were identified that are common across all catalytic mechanisms proposed for Mn-carbonyl complexes, and their structures were used to calculate descriptors for each of the 55 Mn-carbonyl complexes. These electronic-structure-based descriptors encompass the binding energies, the highest occupied and lowest unoccupied molecular orbitals, and partial charges. Trends in turnover frequency and overpotential with these descriptors were analyzed to afford meaningful physical insights into what ligand characteristics lead to good catalytic performance, and how this is affected by the reaction conditions. These insights can be expected to significantly contribute to the rational design of more active Mn-carbonyl electrocatalysts.
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Affiliation(s)
- Jacob Florian
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, U.K.
| | - Jacqueline M. Cole
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, U.K.,ISIS
Neutron and Muon Source, STFC Rutherford
Appleton Laboratory, Harwell Campus for Science and Innovation, Didcot OX11 0QX, U.K.,
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7
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Ludwig S, Hamann FM, Helmdach K, Villinger A, Seidel WW. Tuning the potential of redox-active diphosphine ligands based on the alkyne complexes [Tp*W(CO)L{η 2-C 2(PPh 2) 2}]. Dalton Trans 2023; 52:326-337. [PMID: 36504075 DOI: 10.1039/d2dt02794a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Eleven complexes with the general formula [Tp*W(CO)L{η2-C2(PPh2)2}]n+ {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)-borate, L = F-, Cl-, Br-, I-, MeS-, PhS-, pyCH2S-, CN- and TfO-; n = 0 and L = CH3CN and pyridine; n = 1} have been synthesized and fully characterized. Depending on L, the oxidation process from W(II) to W(III) is detected between -0.28 and +0.55 V vs. Fc/Fc+ and the spectroscopic properties (X-ray, IR, and NMR) are influenced according to the electron-rich or electron-poor character of the central metal. The basicity of the alkyne complex-based phosphine groups was estimated by the 31P/77Se coupling method of the corresponding diselenides. Selected examples of the dppa-complex ligands were converted into the corresponding κ2-PdCl2 chelate complexes and employed in a Sonogashira reaction in order to estimate the effect of L on the catalytic behaviour of the dinuclear complexes. While the spectroscopic properties show a good correlation with the redox potential in a mostly linear fashion, catalytic activity is influenced only slightly. The effect of PdCl2 coordination on the alkyne complex is evident from the W(II)/W(III) redox potentials measured by cyclic voltammetry supported by a change of the CO stretching frequency in IR. A comparison of the molecular structures of the alkyne complexes with terminal phosphine groups and the PdCl2 chelate complexes all determined by XRD shows the essential flexibility of the bend-back angles in the alkyne complex moiety.
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Affiliation(s)
- Stephan Ludwig
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Friederike M Hamann
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. .,Leibniz Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Kai Helmdach
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Wolfram W Seidel
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. .,Leibniz Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany
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8
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Singh K, Kundu A, Adhikari D. Ligand-Based Redox: Catalytic Applications and Mechanistic Aspects. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kirti Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
| | - Abhishek Kundu
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
| | - Debashis Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
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9
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Hollingsworth WM, Hill EA. Exploring the potential role of heavy pnictogen elements in ligand design for new metal-ligand cooperative chemistry. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2124863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- W. M. Hollingsworth
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
| | - E. A. Hill
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
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10
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Grills DC, Layne BH, Wishart JF. Coupling Pulse Radiolysis with Nanosecond Time-Resolved Step-Scan Fourier Transform Infrared Spectroscopy: Broadband Mid-Infrared Detection of Radiolytically Generated Transients. APPLIED SPECTROSCOPY 2022; 76:1142-1153. [PMID: 35414202 DOI: 10.1177/00037028221097429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We describe the first implementation of broadband, nanosecond time-resolved step-scan Fourier transform infrared (S2-FT-IR) spectroscopy at a pulse radiolysis facility. This new technique allows the rapid acquisition of nano- to microsecond time-resolved infrared (TRIR) spectra of transient species generated by pulse radiolysis of liquid samples at a pulsed electron accelerator. Wide regions of the mid-infrared can be probed in a single experiment, which often takes < 20-30 min to complete. It is therefore a powerful method for rapidly locating the IR absorptions of short-lived, radiation-induced species in solution, and for directly monitoring their subsequent reactions. Time-resolved step-scan FT-IR detection for pulse radiolysis thus complements our existing narrowband quantum cascade laser-based pulse radiolysis-TRIR detection system, which is more suitable for acquiring single-shot kinetics and narrowband TRIR spectra on small-volume samples and in strongly absorbing solvents, such as water. We have demonstrated the application of time-resolved step-scan FT-IR spectroscopy to pulse radiolysis by probing the metal carbonyl and organic carbonyl vibrations of the one-electron-reduced forms of two Re-based CO2 reduction catalysts in acetonitrile solution. Transient IR absorption bands with amplitudes on the order of 1 × 10-3 are easily detected on the sub-microsecond timescale using electron pulses as short as 250 ns.
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Affiliation(s)
- David C Grills
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
| | - Bobby H Layne
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
| | - James F Wishart
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
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11
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Capulín Flores L, Paul LA, Siewert I, Havenith R, Zúñiga-Villarreal N, Otten E. Neutral Formazan Ligands Bound to the fac-(CO) 3Re(I) Fragment: Structural, Spectroscopic, and Computational Studies. Inorg Chem 2022; 61:13532-13542. [PMID: 35969867 PMCID: PMC9438031 DOI: 10.1021/acs.inorgchem.2c02168] [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] [Indexed: 11/30/2022]
Abstract
Metal complexes with ligands that coordinate via the nitrogen atom of azo (N═N) or imino (C═N) groups are of interest due to their π-acceptor properties and redox-active nature, which leads to interesting (opto)electronic properties and reactivity. Here, we describe the synthesis and characterization of rhenium(I) tricarbonyl complexes with neutral N,N-bidentate formazans, which possess both N═N and C═N fragments within the ligand backbone (Ar1-NH-N═C(R3)-N═N-Ar5). The compounds were synthesized by reacting equimolar amounts of [ReBr(CO)5] and the corresponding neutral formazan. X-ray crystallographic and spectroscopic (IR, NMR) characterization confirmed the generation of formazan-type species with the structure fac-[ReBr(CO)3(κ2-N2,N4(Ar1-N1H-N2═C(R3)-N3═N4-Ar5))]. The formazan ligand coordinates the metal center in the 'open' form, generating a five-membered chelate ring with a pendant NH arm. The electronic absorption and emission properties of these complexes are governed by the presence of low-lying π*-orbitals on the ligand as shown by DFT calculations. The high orbital mixing between the metal and ligand results in photophysical properties that contrast to those observed in fac-[ReBr(CO)3(L,L)] species with α-diimine ligands.
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Affiliation(s)
- Liliana Capulín Flores
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, 04510 México, D.F., México
| | - Lucas A Paul
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Remco Havenith
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Noé Zúñiga-Villarreal
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, 04510 México, D.F., México
| | - Edwin Otten
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Priyatharsini M, Mishra I, Shankar B, Srinivasan N, Krishnakumar RV, Sathiyendiran M. fac-Re(CO)3 core-based complex featuring benzimidazole as pendant motif from hydroxyquinoline and pyridylbenzimidazole. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.122052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Mechanistic insight into electrocatalytic CO2 reduction using Lewis acid-base pairs. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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14
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Novel Oxidovanadium Complexes with Redox-Active R-Mian and R-Bian Ligands: Synthesis, Structure, Redox and Catalytic Properties. Molecules 2021; 26:molecules26185706. [PMID: 34577177 PMCID: PMC8465707 DOI: 10.3390/molecules26185706] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/15/2021] [Accepted: 09/17/2021] [Indexed: 11/19/2022] Open
Abstract
A new monoiminoacenaphthenone 3,5-(CF3)2C6H3-mian (complex 2) was synthesized and further exploited, along with the already known monoiminoacenaphthenone dpp-mian, to obtain oxidovanadium(IV) complexes [VOCl2(dpp-mian)(CH3CN)] (3) and [VOCl(3,5-(CF3)2C6H3-bian)(H2O)][VOCl3(3,5-(CF3)2C6H3-bian)]·2.85DME (4) from [VOCl2(CH3CN)2(H2O)] (1) or [VCl3(THF)3]. The structure of all compounds was determined using X-ray structural analysis. The vanadium atom in these structures has an octahedral coordination environment. Complex 4 has an unexpected structure. Firstly, it contains 3,5-(CF3)2C6H3-bian instead of 3,5-(CF3)2C6H3-mian. Secondly, it has a binuclear structure, in contrast to 3, in which two oxovanadium parts are linked to each other through V=O···V interaction. This interaction is non-covalent in origin, according to DFT calculations. In structures 2 and 3, non-covalent π-π staking interactions between acenaphthene moieties of the neighboring molecules (distances are 3.36–3.40 Å) with an estimated energy of 3 kcal/mol were also found. The redox properties of the obtained compounds were studied using cyclic voltammetry in solution. In all cases, the reduction processes initiated by the redox-active nature of the mian or bian ligand were identified. The paramagnetic nature of complexes 3 and 4 has been proven by EPR spectroscopy. Complexes 3 and 4 exhibited high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The yields of products of cyclohexane oxidation were 43% (complex 3) and 27% (complex 4). Based on the data regarding the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play the most crucial role in the reaction. The initial products in the reactions with alkanes are alkyl hydroperoxides, which are easily reduced to their corresponding alcohols by the action of triphenylphosphine (PPh3). According to the DFT calculations, the difference in the catalytic activity of 3 and 4 is most likely associated with a different mechanism for the generation of ●OH radicals. For complex 4 with electron-withdrawing CF3 substituents at the diimine ligand, an alternative mechanism, different from Fenton’s and involving a redox-active ligand, is assumed.
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15
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Mishra I, Priyatharsini M, Sathiyendiran M. Synthesis and characterization of binuclear manganese carbonyl complex of 1,4-bis(2-(2′-hydroxyphenyl)benzimidazol-1-yl)benzene and dimethylaminopyridine. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Kinzel NW, Werlé C, Leitner W. Transition Metal Complexes as Catalysts for the Electroconversion of CO 2 : An Organometallic Perspective. Angew Chem Int Ed Engl 2021; 60:11628-11686. [PMID: 33464678 PMCID: PMC8248444 DOI: 10.1002/anie.202006988] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/11/2020] [Indexed: 12/17/2022]
Abstract
The electrocatalytic transformation of carbon dioxide has been a topic of interest in the field of CO2 utilization for a long time. Recently, the area has seen increasing dynamics as an alternative strategy to catalytic hydrogenation for CO2 reduction. While many studies focus on the direct electron transfer to the CO2 molecule at the electrode material, molecular transition metal complexes in solution offer the possibility to act as catalysts for the electron transfer. C1 compounds such as carbon monoxide, formate, and methanol are often targeted as the main products, but more elaborate transformations are also possible within the coordination sphere of the metal center. This perspective article will cover selected examples to illustrate and categorize the currently favored mechanisms for the electrochemically induced transformation of CO2 promoted by homogeneous transition metal complexes. The insights will be corroborated with the concepts and elementary steps of organometallic catalysis to derive potential strategies to broaden the molecular diversity of possible products.
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Affiliation(s)
- Niklas W. Kinzel
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Institut für Technische und Makromolekulare Chemie (ITMC)RWTH Aachen UniversityWorringer Weg 252074AachenGermany
| | - Christophe Werlé
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Ruhr University BochumUniversitätsstr. 15044801BochumGermany
| | - Walter Leitner
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Institut für Technische und Makromolekulare Chemie (ITMC)RWTH Aachen UniversityWorringer Weg 252074AachenGermany
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17
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Yang Y, Ertem MZ, Duan L. An amide-based second coordination sphere promotes the dimer pathway of Mn-catalyzed CO 2-to-CO reduction at low overpotential. Chem Sci 2021; 12:4779-4788. [PMID: 34168756 PMCID: PMC8179605 DOI: 10.1039/d0sc05679k] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/06/2021] [Indexed: 01/28/2023] Open
Abstract
The [fac-Mn(bpy)(CO)3Br] complex is capable of catalyzing the electrochemical reduction of CO2 to CO with high selectivity, moderate activity and large overpotential. Several attempts have been made to lower the overpotential and to enhance the catalytic activity of this complex by manipulating the second-coordination sphere of manganese and using relatively stronger acids to promote the protonation-first pathway. We report herein that the complex [fac-Mn(bpy-CONHMe)(CO)3(MeCN)]+ ([1-MeCN]+; bpy-CONHMe = N-methyl-(2,2'-bipyridine)-6-carboxamide) as a pre-catalyst could catalyze the electrochemical reduction of CO2 to CO with low overpotential and high activity and selectivity. Combined experimental and computational studies reveal that the amide NH group not only decreases the overpotential of the Mn catalyst by promoting the dimer and protonation-first pathways in the presence of H2O but also enhances the CO2 electroreduction activity by facilitating C-OH bond cleavage, making [1-MeCN]+ an efficient CO2 reduction pre-catalyst at low overpotential.
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Affiliation(s)
- Yong Yang
- Department of Chemistry, Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Energy Materials for Electric Power, Southern University of Science and Technology Shenzhen 518055 China
| | - Mehmed Z Ertem
- Chemistry Division, Energy & Photon Sciences, Brookhaven National Laboratory Upton NY 11973-5000 USA
| | - Lele Duan
- Department of Chemistry, Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Energy Materials for Electric Power, Southern University of Science and Technology Shenzhen 518055 China
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18
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The first use of tri(1-naphthyl)phosphine oxide as ligand for rhenium(I)- complexes from phosphine via a one-pot approach. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2020.121657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Kinzel NW, Werlé C, Leitner W. Übergangsmetallkomplexe als Katalysatoren für die elektrische Umwandlung von CO
2
– eine metallorganische Perspektive. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202006988] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Niklas W. Kinzel
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Institut für Technische und Makromolekulare Chemie (ITMC) RWTH Aachen University Worringer Weg 2 52074 Aachen Deutschland
| | - Christophe Werlé
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Deutschland
| | - Walter Leitner
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Institut für Technische und Makromolekulare Chemie (ITMC) RWTH Aachen University Worringer Weg 2 52074 Aachen Deutschland
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20
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Chowdhury SN, Biswas S, Das P, Paul S, Biswas AN. Oxygen Reduction Assisted by the Concert of Redox Activity and Proton Relay in a Cu(II) Complex. Inorg Chem 2020; 59:14012-14022. [PMID: 32916051 DOI: 10.1021/acs.inorgchem.0c01776] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A copper complex, [Cu(dpaq)](ClO4) (1), of a monoanionic pentadentate amidate ligand (dpaq) has been isolated and characterized to study its efficacy toward electrocatalytic reduction of oxygen in neutral aqueous medium. The Cu(II) mononuclear complex, poised in a distorted trigonal bipyramidal structure, reduces oxygen at an onset potential of 0.50 V vs RHE. Kinetics study by hydrodynamic voltammetry and chronoamperometry suggests a stepwise mechanism for sequential reduction of O2 to H2O2 to H2O at a single-site Cu-catalyst. The foot-of-the-wave analysis records a turnover frequency of 5.65 × 102 s-1. At pH 7.0, complex 1 undergoes a quasi-reversible mixed metal-ligand-based reduction and triggers the reduction of dioxygen to water. Electrochemical studies in tandem with quantum chemical investigation, conducted at different redox states, portray the active participation of ligand in completing the process of proton-coupled electron transfer internally. The protonated carboxamido moiety acts as a proton relay, while the quinoline-based orbital supplies the necessary redox equivalent for the conversion of complex 1 to Cu(II)-hydroperoxo species. Thus, a suitable combination of redox non-innocence and proton shuttling functionality in the ligand makes it an effective electron-proton-transfer mediator and subsequently assists the process of oxygen reduction.
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Affiliation(s)
- Srijan Narayan Chowdhury
- Department of Chemistry, National Institute of Technology Sikkim, Barfung Block, Ravangla, South Sikkim 737139, India
| | - Sachidulal Biswas
- Department of Chemistry, National Institute of Technology Sikkim, Barfung Block, Ravangla, South Sikkim 737139, India
| | - Purak Das
- Department of Chemistry, Rishi Bankim Chandra College for Women, Naihati 743165, India
| | - Satadal Paul
- Department of Science and Humanities, Darjeeling Polytechnic, Kurseong 734203, India
| | - Achintesh N Biswas
- Department of Chemistry, National Institute of Technology Sikkim, Barfung Block, Ravangla, South Sikkim 737139, India
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21
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Khan FF, Chowdhury AD, Lahiri GK. Bond Activations Assisted by Redox Active Ligand Scaffolds. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000005] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Farheen Fatima Khan
- Department of Chemistry; Indian Institute of Technology Bombay; Powai 400076 Mumbai India
| | | | - Goutam Kumar Lahiri
- Department of Chemistry; Indian Institute of Technology Bombay; Powai 400076 Mumbai India
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22
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Kurtz DA, Dhakal B, McDonald LT, Nichol GS, Felton GAN. Inter-ligand intramolecular through-space anisotropic shielding in a series of manganese carbonyl phosphorous compounds. Dalton Trans 2019; 48:14926-14935. [PMID: 31559411 DOI: 10.1039/c9dt03100f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Eight novel manganese carbonyl complexes of the type [Mn(bpy-tBu)(CO)3PR3]+ (bpy-tBu = 4,4'-di-tert-butyl-2,2'-bipyridine; R = Cy, nBu, Me, p-tol, Ph, p-F-Ph, OEt, and OMe), have been synthesized and characterized by 1H NMR, FTIR, UV/Vis, HRMS and CV. X-ray crystallographic structures of [Mn(bpy-tBu)(CO)3(PCy3)]+ and [Mn(bpy-tBu)(CO)3(PPh3)]+ were obtained. The short Mn-P bond length allows for close proximity of the bipyridine ligand and the phosphine R groups, resulting in strong anisotropic shielding of certain bipyridine protons by aryl R groups (reordering the bipyridine 1H NMR pattern in the most extreme case). Electrochemical analysis of the compound series reveals that while each is a competent precatalyst for electrochemical carbon dioxide reduction (to carbon monoxide), the lability of the PR3 ligand results in similar catalytic performance amongst the series.
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Affiliation(s)
- Daniel A Kurtz
- Rowland Institute at Harvard, Harvard University, Cambridge, MA 02142, USA
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23
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McKinnon M, Belkina V, Ngo KT, Ertem MZ, Grills DC, Rochford J. An Investigation of Electrocatalytic CO 2 Reduction Using a Manganese Tricarbonyl Biquinoline Complex. Front Chem 2019; 7:628. [PMID: 31608271 PMCID: PMC6771302 DOI: 10.3389/fchem.2019.00628] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/02/2019] [Indexed: 11/18/2022] Open
Abstract
The subject of this study [fac-Mn(bqn)(CO)3(CH3CN)]+ (bqn = 2,2′-biquinoline), is of particular interest because the bqn ligand exhibits both steric and electronic influence over the fundamental redox properties of the complex and, consequently, its related catalytic properties with respect to the activation of CO2. While not a particularly efficient catalyst for CO2 to CO conversion, in-situ generation and activity measurements of the [fac-Mn(bqn)(CO)3]− active catalyst allows for a better understanding of ligand design at the Mn center. By making direct comparisons to the related 2,2′-bipyridyl (bpy), 1,10-phenanthroline (phen), and 2,9-dimethyl-1,10-phenanthroline (dmphen) ligands via a combination of voltammetry, infrared spectroelectrochemistry, controlled potential electrolysis and computational analysis, the role of steric vs. electronic influences on the nucleophilicity of Mn-based CO2 reduction electrocatalysts is discussed.
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Affiliation(s)
- Meaghan McKinnon
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, United States
| | - Veronika Belkina
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, United States
| | - Ken T Ngo
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, United States
| | - Mehmed Z Ertem
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, United States
| | - David C Grills
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, United States
| | - Jonathan Rochford
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, United States
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24
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Fokin I, Denisiuk A, Würtele C, Siewert I. The Impact of a Proton Relay in Binuclear α-Diimine-Mn(CO)3 Complexes on the CO2 Reduction Catalysis. Inorg Chem 2019; 58:10444-10453. [DOI: 10.1021/acs.inorgchem.9b00992] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Igor Fokin
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Alisa Denisiuk
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Christian Würtele
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
- Universität Göttingen, International Center for Advanced Studies of Energy Conversion, 37077 Göttingen, Germany
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25
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Narro AL, Arman HD, Tonzetich ZJ. Manganese Chemistry of Anionic Pyrrole-Based Pincer Ligands. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00058] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ana L. Narro
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
| | - Hadi D. Arman
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
| | - Zachary J. Tonzetich
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
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