1
|
Lewine H, Teigen AG, Trausch AM, Lindblom KM, Seda T, Reinheimer EW, Kowalczyk T, Gilbertson JD. Sequential Deoxygenation of CO 2 and NO 2- via Redox-Control of a Pyridinediimine Ligand with a Hemilabile Phosphine. Inorg Chem 2023; 62:15173-15179. [PMID: 37669231 PMCID: PMC10520972 DOI: 10.1021/acs.inorgchem.3c02323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Indexed: 09/07/2023]
Abstract
The deoxygenation of environmental pollutants CO2 and NO2- to form value-added products is reported. CO2 reduction with subsequent CO release and NO2- conversion to NO are achieved via the starting complex Fe(PPhPDI)Cl2 (1). 1 contains the redox-active pyridinediimine (PDI) ligand with a hemilabile phosphine located in the secondary coordination sphere. 1 was reduced with SmI2 under a CO2 atmosphere to form the direduced monocarbonyl Fe(PPhPDI)(CO) (2). Subsequent CO release was achieved via oxidation of 2 using the NOx- source, NO2-. The resulting [Fe(PPhPDI)(NO)]+ (3) mononitrosyl iron complex (MNIC) is formed as the exclusive reduction product due to the hemilabile phosphine. 3 was investigated computationally to be characterized as {FeNO}7, an unusual intermediate-spin Fe(III) coupled to triplet NO- and a singly reduced PDI ligand.
Collapse
Affiliation(s)
- Hanalei
R. Lewine
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| | - Allison G. Teigen
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| | - April M. Trausch
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| | - Kaitlyn M. Lindblom
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| | - Takele Seda
- Department
of Physics, Western Washington University, Bellingham, Washington98225, United States
| | | | - Tim Kowalczyk
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| | - John D. Gilbertson
- Department
of Chemistry, Western Washington University, Bellingham, Washington98225, United States
| |
Collapse
|
2
|
Ghosh P, Stauffer M, Ahmed ME, Bertke JA, Staples RJ, Warren TH. Thiol and H 2S-Mediated NO Generation from Nitrate at Copper(II). J Am Chem Soc 2023; 145:12007-12012. [PMID: 37224264 PMCID: PMC10367543 DOI: 10.1021/jacs.3c00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Reduction of nitrate is an essential, yet challenging chemical task required to manage this relatively inert oxoanion in the environment and biology. We show that thiols, ubiquitous reductants in biology, convert nitrate to nitric oxide at a Cu(II) center under mild conditions. The β-diketiminato complex [Cl2NNF6]Cu(κ2-O2NO) engages in O-atom transfer with various thiols (RSH) to form the corresponding copper(II) nitrite [CuII](κ2-O2N) and sulfenic acid (RSOH). The copper(II) nitrite further reacts with RSH to give S-nitrosothiols RSNO and [CuII]2(μ-OH)2 en route to NO formation via [CuII]-SR intermediates. The gasotransmitter H2S also reduces nitrate at copper(II) to generate NO, providing a lens into NO3-/H2S crosstalk. The interaction of thiols with nitrate at copper(II) releases a cascade of N- and S-based signaling molecules in biology.
Collapse
Affiliation(s)
- Pokhraj Ghosh
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D. C. 20057, United States
| | - Molly Stauffer
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D. C. 20057, United States
| | - Md Estak Ahmed
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D. C. 20057, United States
| | - Jeffery A Bertke
- Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D. C. 20057, United States
| | - Richard J Staples
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Timothy H Warren
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D. C. 20057, United States
| |
Collapse
|
3
|
Lin WS, Kuwata S. Recent Developments in Reactions and Catalysis of Protic Pyrazole Complexes. Molecules 2023; 28:molecules28083529. [PMID: 37110763 PMCID: PMC10143336 DOI: 10.3390/molecules28083529] [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: 03/16/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Protic pyrazoles (N-unsubstituted pyrazoles) have been versatile ligands in various fields, such as materials chemistry and homogeneous catalysis, owing to their proton-responsive nature. This review provides an overview of the reactivities of protic pyrazole complexes. The coordination chemistry of pincer-type 2,6-bis(1H-pyrazol-3-yl)pyridines is first surveyed as a class of compounds for which significant advances have made in the last decade. The stoichiometric reactivities of protic pyrazole complexes with inorganic nitrogenous compounds are then described, which possibly relates to the inorganic nitrogen cycle in nature. The last part of this article is devoted to outlining the catalytic application of protic pyrazole complexes, emphasizing the mechanistic aspect. The role of the NH group in the protic pyrazole ligand and resulting metal-ligand cooperation in these transformations are discussed.
Collapse
Affiliation(s)
- Wei-Syuan Lin
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1 E4-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Shigeki Kuwata
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu 525-8577, Shiga, Japan
| |
Collapse
|
4
|
Beagan DM, Cabelof AC. Recent advances in metal-mediated nitrogen oxyanion reduction using reductively borylated and silylated N-heterocycles. Dalton Trans 2022; 51:2203-2213. [PMID: 35044399 DOI: 10.1039/d1dt03740d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reduction of nitrogen oxyanions is critical for the remediation of eutrophication caused by anthropogenic perturbations to the natural nitrogen cycle. There are many approaches to nitrogen oxyanion reduction, and here we report our advances in reductive deoxygenation using pre-reduced N-heterocycles. We show examples of nitrogen oxyanion reduction using Cr, Fe, Co, Ni, and Zn, and we evaluate the role of metal choice, number of coordinated oxyanions, and ancillary ligands on the reductive transformations. We report the experimental challenges faced and provide an outlook on new directions to repurpose nitrogen oxyanions into value-added products.
Collapse
Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Alyssa C Cabelof
- Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana, USA
| |
Collapse
|
5
|
Sahoo P, Majumdar M. Reductively disilylated N-heterocycles as versatile organosilicon reagents. Dalton Trans 2021; 51:1281-1296. [PMID: 34889336 DOI: 10.1039/d1dt03331j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The reductively disilylated N-heterocyclic systems 1,4-bis(trimethylsilyl)-1-aza-2,5-cyclohexadiene (1Si), 1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (2Si) and its methyl derivatives (3Si and 4Si), and 1,1'-bis(trimethylsilyl)-4,4'-bipyridinylidene (5Si) are proficient organosilicon reagents owing to their low first vertical ionization potentials and the heterophilicity of the polarized N-Si bonds. These have prompted their reactivity as two-electron reductants or reductive silylations. These reactions benefit from the concomitant rearomatization of the N-heterocycles and liberation of trimethylsilyl halides or (Me3Si)2O, which are mostly volatile or easily removable byproducts. In this perspective, we have discussed the utilization of these reductively disilylated N-heterocyclic systems as versatile reagents in the salt-free reduction of transition metals (A) and main-group halides (B), in organic transformations (C) and in materials syntheses (D).
Collapse
Affiliation(s)
- Padmini Sahoo
- Department of Chemistry, Indian Institute of Science Education and Research, Pune-411008, Maharashtra, India.
| | - Moumita Majumdar
- Department of Chemistry, Indian Institute of Science Education and Research, Pune-411008, Maharashtra, India.
| |
Collapse
|
6
|
Beagan DM, Cabelof AC, Pepin R, Pink M, Carta V, Caulton KG. An Integrated View of Nitrogen Oxyanion Deoxygenation in Solution Chemistry and Electrospray Ion Production. Inorg Chem 2021; 60:17241-17248. [PMID: 34705459 DOI: 10.1021/acs.inorgchem.1c02591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
There has been an increasing interest in chemistry involving nitrogen oxyanions, largely due to the environmental hazards associated with increased concentrations of these anions leading to eutrophication and aquatic "dead zones". Herein, we report the synthesis and characterization of a suite of MNOx complexes (M = Co, Zn: x = 2, 3). Reductive deoxygenation of cobalt bis(nitrite) complexes with bis(boryl)pyrazine is faster for cobalt than previously reported nickel, and pendant O-bound nitrito ligand is still readily deoxygenated, despite potential implication of an isonitrosyl primary product. Deoxygenation of zinc oxyanion complexes is also facile, despite zinc being unable to stabilize a nitrosyl ligand, with liberation of nitric oxide and nitrous oxide, indicating N-N bond formation. X-ray photoelectron spectroscopy is effective for discriminating the types of nitrogen in these molecules. ESI mass spectrometry of a suite of M(NOx)y (x = 2, 3 and y = 1, 2) shows that the primary form of ionization is loss of an oxyanion ligand, which can be alleviated via the addition of tetrabutylammonium (TBA) as a nonintuitive cation pair for the neutral oxyanion complexes. We have shown these complexes to be subject to deoxygenation, and there is evidence for nitrogen oxyanion reduction in several cases in the ESI plume. The attractive force between cation and neutral is explored experimentally and computationally and attributed to hydrogen bonding of the nitrogen oxyanion ligands with ammonium α-CH2 protons. One example of ESI-induced reductive dimerization is mimicked by bulk solution synthesis, and that product is characterized by X-ray diffraction to contain two Co(NO)2+ groups linked by a highly conjugated diazapolyene.
Collapse
Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Alyssa C Cabelof
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Robert Pepin
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Maren Pink
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Veronica Carta
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Kenneth G Caulton
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| |
Collapse
|
7
|
Beagan DM, Maciulis NA, Pink M, Carta V, Huerfano IJ, Chen CH, Caulton KG. A Redox-Active Tetrazine-Based Pincer Ligand for the Reduction of N-Oxyanions Using a Redox-Inert Metal. Chemistry 2021; 27:11676-11681. [PMID: 34008888 DOI: 10.1002/chem.202101302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Indexed: 01/01/2023]
Abstract
The reaction chemistry of the bis-tetrazinyl pyridine ligand (btzp) towards nitrogen oxyanions coordinated to zinc is studied in order to explore the reduction of the NOx - substrates with a redox-active ligand in the absence of redox activity at the metal. Following syntheses and characterization of (btzp)ZnX2 for X=Cl, NO3 and NO2 , featuring O-Zn linkage of both nitrogen oxyanions, it is shown that a silylating agent selectively delivers silyl substituents to tetrazine nitrogens, without reductive deoxygenation of NOx -1 . A new synthesis of the highly hydrogenated H4 btzp, containing two dihydrotetrazine reductants is described as is the synthesis and characterization of (H4 btzp)ZnX2 for X=Cl and NO3 , both of which show considerable hydrogen bonding potential of the dihydrotetrazine ring NH groups. The (H4 btzp)ZnCl2 complex does not bind zinc in the pincer pocket, but instead H4 btzp becomes a bridge between neighboring atoms through tetrazine nitrogen atoms, forming a polymeric chain. The reaction of AgNO2 with (H4 btzp)ZnCl2 is shown to proceed with fast nitrite deoxygenation, yielding water and free NO. Half of the H4 btzp reducing equivalents form Ag0 and thus the chloride ligand remains coordinated to the zinc metal center to yield (btzp)ZnCl2 . To compare with AgNO2 , experiments of (H4 btzp)ZnCl2 with NaNO2 result in salt metathesis between chloride and nitrite, highlighting the importance of a redox-active cation in the reduction of nitrite to NO.
Collapse
Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - Nicholas A Maciulis
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - Maren Pink
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - Veronica Carta
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - I J Huerfano
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - Chun-Hsing Chen
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| | - Kenneth G Caulton
- Department of Chemistry, Indiana University, 47405, Bloomington, Indiana, USA
| |
Collapse
|
8
|
|
9
|
Cabelof AC, Carta V, Caulton KG. A proton-responsive ligand becomes a dimetal linker for multisubstrate assembly via nitrate deoxygenation. Chem Commun (Camb) 2021; 57:2780-2783. [PMID: 33598673 DOI: 10.1039/d0cc07886g] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A bidentate pyrazolylpyridine ligand (HL) was installed on divalent nickel to give [(HL)2Ni(NO3)]NO3. This compound reacts with a bis-silylated heterocycle, 1,4-bis-(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (TMS2Pz) to simultaneously reduce one of the nitrate ligands and deprotonate one of the HL ligands, giving octahedral (HL)(L-)Ni(NO3). The mononitrate species formed is then further reacted with TMS2Pz to doubly deoxygenate nitrate and form [(L-)Ni(NO)]2, dimeric via bridging pyrazolate with bent nitrosyl ligands, representing a two-electron reduction of coordinated nitrate. Independent synthesis of a dimeric species [(L-)Ni(Br)]2 is reported and effectively assembles two metals with better atom economy.
Collapse
Affiliation(s)
- Alyssa C Cabelof
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Veronica Carta
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Kenneth G Caulton
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| |
Collapse
|
10
|
Beagan DM, Cabelof AC, Caulton KG. Back donation, intramolecular electron transfer and N-O bond scission targeting nitrogen oxyanion reduction: how can a metal complex assist? Dalton Trans 2021; 50:2149-2157. [PMID: 33491695 DOI: 10.1039/d0dt03430d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A density functional theory exploration studies a range of ancillary coordinated ligands accompanying nitrogen oxyanions with the goal of promoting back donation towards varied nitrogen oxidation states. Evaluation of a suite of Ru and Rh metal complexes reveals minimum back donation to the κ1-nitrogen oxyanion ligand, even upon one-electron reduction. This reveals some surprising consequences of reduction, including redox activity at pyridine and nitrogen oxyanion dissociation. Bidentate nitrate was therefore considered, where ancillary ligands enforce geometries that maximize M-NOx orbital overlap. This strategy is successful and leads to full electron transfer in several cases to form a pyramidal radical NO32- ligand. The impact of ancillary ligand on degree of nitrate reduction is probed by comparing the powerful o-donor tris-carbene borate (TCB) to a milder donor, tris-pyrazolyl borate (Tp). This reveals that with the milder Tp donor, nitrate reduction is only seen upon addition of a Lewis base. Protonation of neutral and anionic (TCB)Ru(κ2-NO3) at both terminal and internal oxygens reveals exergonic N-O bond cleavage for the reduced species, with one electron coming from Ru, yielding a RuIII hydroxide product. Comparison of H+ to Na+ electrophile shows weaker progress towards N-O bond scission. Finally, calculations on (TCB)Fe(κ2-NO3) and [(TCB)Fe(κ2-NO3)]- show that electron transfer to nitrate is possible even with an earth abundant 3d metal.
Collapse
Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | | | | |
Collapse
|
11
|
Cabelof AC, Erny AM, Carta V, Pink M, Caulton KG. Anion metathesis and chlorination of late transition metal pincer complexes: Comparing Co, Rh and Zn. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
12
|
Marks WR, Baumgardner DF, Reinheimer EW, Gilbertson JD. Complete denitrification of nitrate and nitrite to N 2 gas by samarium(II) iodide. Chem Commun (Camb) 2020; 56:11441-11444. [PMID: 32851391 DOI: 10.1039/d0cc04115g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The reduction of nitrogen oxides (NxOyn-) to dinitrogen gas by samarium(ii) iodide is reported. The polyoxoanions nitrate (NO3-) and nitrite (NO2-), as well as nitrous oxide (N2O) and nitric oxide (NO) were all shown to react with stoichiometric amounts of SmI2 in THF for the complete denitrification to N2.
Collapse
Affiliation(s)
- Walker R Marks
- Department of Chemistry, Western Washington University, Bellingham, Washington 98225, USA.
| | | | | | | |
Collapse
|
13
|
Cabelof AC, Carta V, Chen CH, Caulton KG. Nitrogen oxyanion reduction by Co(ii) augmented by a proton responsive ligand: recruiting multiple metals. Dalton Trans 2020; 49:7891-7896. [PMID: 32478346 DOI: 10.1039/d0dt01298j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Deoxygenation of nitrite oxygen with divalent cobalt was achieved using (PNNH)CoCl2, carrying a pyridyl pincer ligand with one P(t-Bu)2 arm and one pyrazole arm. Reaction of (PNNH)CoCl2 with NaNO2 at a 2 : 5 mole ratio promptly forms equimolar (PNNH)Co(NO2)3 and (PNN)Co(NO2)(NO), {CoNO}8 with the lost ligand proton combined with removed oxo as hydroxide. These two CoIII products are characterized, showing a bent CoNO unit as the fate of the reduced nitrogen. DFT calculations are consistent with two one-electron CoII reductants binding to one NO2- bridge, then proton transfer being needed for facile N/O bond scission. A species detected by low temperature execution of this reaction contains cobalt in two oxidation states with an N,O bridging nitro group and pincer ligands that have been deprotonated, showing the active participation of the proton responsive ligand.
Collapse
Affiliation(s)
- Alyssa C Cabelof
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA..
| | - Veronica Carta
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA..
| | - Chun-Hsing Chen
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA..
| | - Kenneth G Caulton
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA..
| |
Collapse
|
14
|
Akula N, Sharma N, Lohegaonkar A, Ogale SB, Majumdar M. Coherent Solution-phase Synthesis of a Germanium-Graphitic Nanocomposite and Its Evaluation for Lithium-Ion Battery Anodes: Non-innocent Role of the Mashima Reagent. Chem Asian J 2020; 15:585-589. [PMID: 32017407 DOI: 10.1002/asia.201901704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/26/2020] [Indexed: 12/15/2022]
Abstract
The organosilicon reagent 1,4-bis-(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene 2 plays the binary role of the simultaneous reduction of GeCl2 .dioxane 1 dissolved in oleylamine to Ge nanocrystals and the formation of graphitic sheets under hot-injection conditions. This colloidal synthetic route to germanium nanocrystals embedded on N-doped graphitic nanosheets Ge/NG is free of any template or catalyst and involves easy purification techniques. The Ge/NG/C obtained after carbonization has been explored for anode performance in lithium-ion batteries. Both Ge/NG and Ge/NG/C can be obtained on a gram scale and are bottleable under argon for months.
Collapse
Affiliation(s)
- Naveenkumar Akula
- Department of Chemistry, Indian Institute of Science, Education and Research, Pune, Dr. Homi Bhabha Road, Pune, 411008, Maharashtra, India
| | - Neha Sharma
- Department of Physics, Indian Institute of Science, Education and Research, Pune, Dr. Homi Bhabha Road, Pune, 411008, Maharashtra, India
| | - Apurva Lohegaonkar
- Department of Physics, Indian Institute of Science, Education and Research, Pune, Dr. Homi Bhabha Road, Pune, 411008, Maharashtra, India
| | - Satishchandra B Ogale
- Department of Physics, Indian Institute of Science, Education and Research, Pune, Dr. Homi Bhabha Road, Pune, 411008, Maharashtra, India
| | - Moumita Majumdar
- Department of Chemistry, Indian Institute of Science, Education and Research, Pune, Dr. Homi Bhabha Road, Pune, 411008, Maharashtra, India
| |
Collapse
|
15
|
Drummond MJ, Miller TJ, Ford CL, Fout AR. Catalytic Perchlorate Reduction Using Iron: Mechanistic Insights and Improved Catalyst Turnover. ACS Catal 2020. [DOI: 10.1021/acscatal.9b05029] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Michael J. Drummond
- School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Tabitha J. Miller
- School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Courtney L. Ford
- School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Alison R. Fout
- School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| |
Collapse
|
16
|
Beagan DM, Carta V, Caulton KG. A reagent for heteroatom borylation, including iron mediated reductive deoxygenation of nitrate yielding a dinitrosyl complex. Dalton Trans 2020; 49:1681-1687. [PMID: 31956885 DOI: 10.1039/d0dt00077a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
4,4'-Bipyridyl is shown to be a catalyst for transfer of pinacolboryl groups from (Bpin)2 to nitrogen heterocycles and to Me3SiN3. Using stoichiometric (Bpin)2(pyrazine) or (Bpin)2(bipyridine) in an analogous manner, an aromatic nitro group is deoxygenated and subsequently borylated, and four-fold deoxygenation of (DIM)Fe(NO3)2(MeCN) to yield the dinitrosyl complex (DIM)Fe(NO)2 is facile. The co-product O(Bpin)2 is the quantitative fate of the removed oxo groups. With borylation of both nitrogen heterocycles and doubly deoxygenating two nitrates coordinated to a single metal center, broad spectrum methodology is demonstrated.
Collapse
Affiliation(s)
- Daniel M Beagan
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Veronica Carta
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Kenneth G Caulton
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| |
Collapse
|
17
|
Baumgardner DF, Parks WE, Gilbertson JD. Harnessing the active site triad: merging hemilability, proton responsivity, and ligand-based redox-activity. Dalton Trans 2020; 49:960-965. [PMID: 31907502 PMCID: PMC7386000 DOI: 10.1039/c9dt04470a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Metalloenzymes catalyze many important reactions by managing the proton and electron flux at the enzyme active site. The motifs utilized to facilitate these transformations include hemilabile, redox-active, and so called proton responsive sites. Given the importance of incorporating and understanding these motifs in the area of coordination chemistry and catalysis, we highlight recent milestones in the field. Work incorporating the triad of hemilability, redox-activity, and proton responsivity into single ligand scaffolds will be described.
Collapse
Affiliation(s)
- Douglas F Baumgardner
- Department of Chemistry, Western Washington University, Bellingham, Washington 98225, USA.
| | - Wyatt E Parks
- Department of Chemistry, Western Washington University, Bellingham, Washington 98225, USA.
| | - John D Gilbertson
- Department of Chemistry, Western Washington University, Bellingham, Washington 98225, USA.
| |
Collapse
|
18
|
Labrum NS, Pink M, Chen C, Caulton KG. Reactivity of an Unusual Divalent Chromium Aggregate Supported by a Multifunctional Bis(pyrazolate) Pincer Ligand. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nicholas S. Labrum
- Department of Chemistry and the Molecular Structure Center Indiana University Bloomington 47405 Indiana USA
| | - Maren Pink
- Department of Chemistry and the Molecular Structure Center Indiana University Bloomington 47405 Indiana USA
| | - Chun‐Hsing Chen
- Department of Chemistry and the Molecular Structure Center Indiana University Bloomington 47405 Indiana USA
| | - Kenneth G. Caulton
- Department of Chemistry and the Molecular Structure Center Indiana University Bloomington 47405 Indiana USA
| |
Collapse
|
19
|
Tsurugi H, Mashima K. Salt-Free Reduction of Transition Metal Complexes by Bis(trimethylsilyl)cyclohexadiene, -dihydropyrazine, and -4,4'-bipyridinylidene Derivatives. Acc Chem Res 2019; 52:769-779. [PMID: 30794373 DOI: 10.1021/acs.accounts.8b00638] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chemical reduction of transition metals provides the corresponding low-valent transition metal species as a key step for generating catalytically active species in metal-assisted organic transformations and is a fundamental unit reaction for preparing organometallic complexes. A variety of metal-based reductants, such as metal powders and organometallic reagents of alkali and alkaline-earth metals, have been developed to date to access low-valent metal species. During the reduction, however, reductant-derived metal salts are formed as reaction waste, some of which often interact with the reactive low-valent metal center, thereby disrupting the catalytic performance and hampering the isolation of organometallic complexes as a result of salt coordination to the coordinatively unsaturated vacant and active sites and the formation of thermally unstable ate complexes. In this Account, we emphasize the synthetic utility and versatility of organic reductants containing two trimethylsilyl groups, i.e., 1,4-bis(trimethylsilyl)cyclohexa-2,5-diene (1a) and its methyl derivative (1b), 1,4-bis(trimethylsilyl)dihydropyrazine (2a) and its dimethyl (2b) and tetramethyl (2c) derivatives, and 1,1'-bis(trimethylsilyl)-4,4'-bipyridinylidene (3), leading to the reduction of various kinds of metal compounds in a salt-free fashion by release of two electrons together with the coproduction of easily removable (hetero)aromatics and trimethylsilyl derivatives from these organic reductants 1-3. When homoleptic chlorides of group 5 and 6 metals are treated with 1a and 1b, in situ-generated highly reactive low-valent metal species react with redox-active molecules such as ethylene, α-diimines, and α-diketones to produce metallacyclopentane, (ene-diamido)metal, and (ene-diolato)metal complexes, respectively. The advantage of the salt-free protocol is further exemplified in the low-valent titanocene-catalyzed Reformatsky-type reaction when 2c is used as a reductant: the yield of the product using the organosilicon reductant is higher than that when manganese powder is used as the reductant for the catalytic Reformatsky-type reaction of ethyl 2-bromoisobutyrate and its derivatives with various aldehydes. Moreover, when halides, carboxylates, and acetylacetonate compounds of late transition metals and main-group elements are treated with the organosilicon reductant 2c, metal(0) particles are smoothly precipitated under mild conditions. Among them, metallic nickel(0) nanoparticles are applicable to reductive biaryl formation and reductive cross-coupling of aryl halides/aryl aldehydes. In addition, reduction of the heterogeneous catalysts on a solid supporting matrix was also achieved by this salt-free reduction method; volatile byproducts are easily removed from the catalyst surface without suppressing the catalytic performance. Thus, the salt-free reduction strategy is a very powerful synthetic method that can be extended to various metals throughout the periodic table.
Collapse
Affiliation(s)
- Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| |
Collapse
|