Abundant Transition Metal Research Articles

Cobalt Catalyzed Enantio- and Regioselective Hydrosilation

Enantioselective and regioselective cobalt-catalyzed hydrosilation has been scarcely reported. Although this transformation catalyzed with other transition metals such as iron or copper is well known, cobalt being an abundant and cheap transition metal makes having its catalyst as an option to expand the "toolbox" highly desirable. In addition, enantioselective and regioselective silyl products can serve as important building blocks for creating chiral synthetic products. For example, chiral silanes can be converted into chiral alcohols via Fleming–Tamao oxidation. To conduct this experiment, 2-vinylnaphlene was chosen as the model substrate and various conditions for the hydrosilation of diphenylsilane were investigated. A variety of cobalt catalysts was screened and uniquely, cobalt chloride triphenylphosphine was used offering a cobalt(I) complex. Then the optimal solvent for this reaction was found to be dioxane. With this information, we screened various chiral ligands. The conversion and the regioselectivity of the reaction were determined with proton 1H-NMR. The enantioselectivity was determined through an HPLC assay.In the study, we were able to perform hydrosilation targeting the Markovnikov product. enantioselectivity was achieved with the optimal ligands, albeit with mild regioselectivity. The implications of this finding show promise for using cobalt for an enantioselective and regioselective hydrosilation reaction. Further steps could be taken toward modifying the ligand to enhance conversion, regioselectivity, and enantioselectivity. In addition, various other substrates and silanes could be explored to improve the scope of this study.

One-Dimensional, First-Row Transition Metal, Core-Shell Architectures as Multifunctional Electrocatalysts in Alkaline and Acidic Conditions

The development of practical electrocatalysts for fuel cells, electrochemical sensors, and batteries requires nanostructured architectures with high catalytic activity and good long-term durability. It is also essential that they have very low or even no platinum content. There has also been a recent emphasis on the importance of designing multifunctional catalysts with the ability to efficiently catalyze a wide-range of electrochemical reactions in both acidic and alkaline media. In light of these requirements, we have developed a solution-based synthetic method to prepare core-shell nanowires consisting of inexpensive and abundant first-row transition metals coated with precious metal shells. The core-shell motif enables a substantial quantity of platinum to be removed from the catalytically inactive core of the material, while also resulting in the ability to tune the activity of platinum through electronic and structural interactions between the two metals. The as-synthesized core-shell nanowires have a complex surface structure that brings together metal oxide and precious metal active sites that are active toward OER and result in a significant reduction in the overpotential for OER when compared with pure Pt and Co nanowires. In addition, we have developed an electrochemical process that selectively removes the metal oxide from the surface of the nanowires enabling the catalysts to be activated toward SOM oxidation in acidic media and ORR in alkaline media. For example, the activated core-shell nanowires display a 1.5-fold and a 4-fold increase in the specific activity and mass activity of methanol oxidation, respectively, relative to a pure platinum nanowire.

Composition-Dependent Electrocatalytic Behavior in First-Transition Metal Nanowires Toward the Oxidation of Small Organic Molecules

Platinum-based catalysts are widely used for the electrochemical oxidation of small organic molecules (SOMs), including methanol, ethanol, and glucose. However, it has some limitations, including high cost and limited availability. Platinum’s performance is also hindered by the formation of carbon monoxide (CO) and other partially oxidized intermediates that strongly bind to the surface and hinder kinetics at low overpotentials. Binary alloys created from Pt and other more abundant transition metals aim to reduce the cost of Pt catalysts as well as alleviate the effects of the CO intermediate on Pt catalysts, thus enhancing the catalytic performance of pure Pt. In this project, we synthesize, characterize, and evaluate the electrocatalytic performance of one-dimensional electrocatalysts created from transition metal nanowires coated with precious metal catalysts. These core-shell NWs were synthesized using a template-based technique that allows for the creation of nanowires of different sizes and compositions. The nanowires were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and powder X-ray diffraction (XRD). The catalytic performance of these NWs toward SOM oxidation was evaluated in acidic conditions utilizing cyclic voltammetry and linear sweep voltammetry. We also investigate the performance of these catalysts toward the oxygen reduction reaction (ORR) utilizing rotating disk electrode measurements. The results reveal that the characteristics of the catalytic performance of the alloy NWs are dependent on their morphology and composition.

Photoredox-active Cr(0) luminophores featuring photophysical properties competitive with Ru(II) and Os(II) complexes

Coordination complexes of precious metals with the d6 valence electron configuration such as Ru(II), Os(II) and Ir(III) are used for lighting applications, solar energy conversion and photocatalysis. Until now, d6 complexes made from abundant first-row transition metals with competitive photophysical and photochemical properties have been elusive. While previous research efforts focused mostly on Fe(II), we disclose that isoelectronic Cr(0) gives access to higher photoluminescence quantum yields and excited-state lifetimes when compared with any other first-row d6 metal complex reported so far. The luminescence behaviour of the metal-to-ligand charge transfer excited states of these Cr(0) complexes is competitive with Os(II) polypyridines. With these Cr(0) complexes, the metal-to-ligand charge transfer states of first-row d6 metal complexes become exploitable in photoredox catalysis, and benchmark chemical reductions proceed efficiently under low-energy red illumination. Here we demonstrate that appropriate molecular design strategies open up new perspectives for photophysics and photochemistry with abundant first-row d6 metals.

Mathematical and Statistical Evaluation of Reverse Osmosis in the Removal of Manganese as a Way to Achieve Sustainable Operating Parameters.

Manganese is the Earth's crust's third most abundant transition metal. Decades of increased mining activities worldwide have inevitably led to the release of large amounts of this metal into the environment, specifically in water resources. Up to a certain level, manganese acts as an essential micronutrient to maintain health and support the growth and development of microorganisms, plants, and animals, while above a specific limit, manganese can cause toxicity in aquatic and terrestrial ecosystems. There are conventional ways to remove manganese from water, such as chemical precipitation, sorption, and biological methods. However, other treatments have yet to be studied much, such as reverse osmosis (RO), which has demonstrated its effectiveness in the removal of heavy metals and could be a suitable alternative for manganese removal if its energy consumption is reduced. This research presents mathematical and statistical modeling of the behavior of a system in laboratory-scale RO. The principal finding was that it is possible to remove Mn using the RO operated with low pressures without decreasing the sustainable removal efficiency. Reducing the operating costs of RO opens the possibility of implementing RO in different contexts where there are problems with water contamination and economic limitations.

Hydrogenation of furfural-to-furfuryl alcohol over La-based inorganic perovskites: A study of oxygen vacancies as catalytic descriptors

Herein we report chemoselective hydrogenation of furfural to furfuryl-alcohol over ABO3 inorganic perovskites containing inexpensive and abundant transition metals (LaMO3 M = Co, Mn, Fe). Firstly, the perovskite catalysts were fully characterized and found to have surface areas ranging from 10 to 30 m2/g. Secondly, the anionic defects within the perovskite lattices were determined using X-ray photoelectron spectroscopy (XPS) and Density Functional Theory (DFT) calculations and quantified in terms of the amount of oxygen vacancies. The catalysts with the highest amount of oxygen vacancies were found to be the least active in the hydrogenation of furfural at high H2 pressure.

Crafting Fast and Efficient H2Evolution Electrocatalysts with Tactical Inclusion of Nucleobases

In order to achieve a hydrogen-driven energy infrastructure that is carbon-neutral, it is imperative that there be a synthetic catalyst that is developed from a non-noble metal. The unique interplay between the abundant transition metal containing an active site and the surrounding protein-based outer coordination sphere (OCS) is the essence of the remarkable H2 production displayed by hydrogenase enzymes. Here, we report a series of biomimetic cobalt complexes [Co(dimethylglyoxime)2(Nnucleobase derivative)Cl] crafted by strategic incorporation of a nucleobase and its derivatives (adenine, adenosine, adenosine monophosphate and hypoxanthine) around a common template. The nucleoside- and nucleotide-appended complexes electrocatalyze H2 evolution from neutral aqueous solutions at a rapid rate (turnover frequencies of ∼13 000 and ∼12 000 s–1, respectively) while operating at an overpotential of <400 mV. The intricate proton exchange network created between the different fractions of nucleobase derivatives is one of the prime reasons behind such fast and energy-efficient catalysis.

The adcA and lmb Genes Play an Important Role in Drug Resistance and Full Virulence of Streptococcus suis.

Streptococcus suis is an recognized zoonotic pathogen of swine and severely threatens human health. Zinc is the second most abundant transition metal in biological systems. Here, we investigated the contribution of zinc to the drug resistance and pathogenesis of S. suis. We knocked out the genes of AdcACB and Lmb, two Zn-binding lipoproteins. Compared to the wild-type strain, we found that the survival rate of this double-mutant strain (ΔadcAΔlmb) was reduced in Zinc-limited medium, but not in Zinc-supplemented medium. Additionally, phenotypic experiments showed that the ΔadcAΔlmb strain displayed impaired adhesion to and invasion of cells, biofilm formation, and tolerance of cell envelope-targeting antibiotics. In a murine infection model, deletion of the adcA and lmb genes in S. suis resulted in a significant decrease in strain virulence, including survival rate, tissue bacterial load, inflammatory cytokine levels, and histopathological damage. These findings show that AdcA and Lmb are important for biofilm formation, drug resistance, and virulence in S. suis. IMPORTANCE Transition metals are important micronutrients for bacterial growth. Zn is necessary for the catalytic activity and structural integrity of various metalloproteins involved in bacterial pathogenic processes. However, how these invaders adapt to host-imposed metal starvation and overcome nutritional immunity remains unknown. Thus, pathogenic bacteria must acquire Zn during infection in order to successfully survive and multiply. The host uses nutritional immunity to limit the uptake of Zn by the invading bacteria. The bacterium uses a set of high-affinity Zn uptake systems to overcome this host metal restriction. Here, we identified two Zn uptake transporters in S. suis, AdcA and Lmb, by bioinformatics analysis and found that an adcA and lmb double-mutant strain could not grow in Zn-deficient medium and was more sensitive to cell envelope-targeting antibiotics. It is worth noting that the Zn uptake system is essential for biofilm formation, drug resistance, and virulence in S. suis. The Zn uptake system is expected to be a target for the development of novel antimicrobial therapies.

The Nephelauxetic Effect Becomes an Important Design Factor for Photoactive First-Row Transition Metal Complexes.

The expansion of d-orbitals as a result of metal-ligand bond covalence, the so-called nephelauxetic effect, is a well-established concept of coordination chemistry, yet its importance for the design of new photoactive complexes based on first-row transition metals is only beginning to be recognized. Until recently, much focus has been on optimizing the ligand field strength, coordination geometries, and molecular rigidity, but now it becomes evident that the nephelauxetic effect can be a game changer regarding the photophysical properties of 3d metal complexes in solution at room temperature. In CrIII and MnIV complexes with the d3 valence electron configuration, the nephelauxetic effect was exploited to shift the well-known ruby-like red luminescence to the near-infrared spectral region. In FeII and CoIII complexes with the low-spin d6 electron configuration, charge-transfer excited states were stabilized with respect to detrimental metal-centered excited states, to improve their properties and to enhance their application potential. In isoelectronic (3d6 ) isocyanide complexes of Cr0 and MnI , the nephelauxetic effect is likely at play as well, enabling luminescence and other favorable photoreactivity. This minireview illustrates the broad applicability of the nephelauxetic effect in tailoring the photophysical and photochemical properties of new coordination compounds made from abundant first-row transition metals.

Enhanced two-electron oxygen reduction for hydrogen peroxide production via fine-tuning the concentration of oxygen vacancies in MoO3−x

Producing hydrogen peroxide (H2O2) electrochemically is a possible alternative to industrial anthraquinone synthesis. Herein, α-MoO3−x catalysts with controllable oxygen vacancies for two-electron Oxygen Reduction (2e− ORR) electrocatalysis have been reported for the first time. Because of the finely tuned oxygen vacancy concentration of α-MoO3−x-400, it is particularly sensitive to the production of H2O2, providing very high selectivity in H2O2 production reaches as high as 93% with an average yield of 310 mmol gcat−1 h−1 over 12 h. In addition to providing us with the most abundant and attractive transition metal oxide (TMO) catalysts yet, this research provides a fresh approach to the rational development of effective TMO catalysts.

Highly selective chromogenic and fluorogenic probe based on benzothiazole‐thiosemicarbazone Schiff base for detection of copper (II) in real samples

AbstractCopper is the third most abundant essential transition metal ion in the human body. It's responsible for important activities in many living things, but excessive intake of Cu2+ can lead to a range of diseases. A colorimetric and turn‐off fluorescent probe (E)‐2‐(5‐(benzothiazol‐2‐yl)‐2‐(diethylamino)‐4‐hydroxybenzylidene)‐N‐phenylhydrazine‐1‐carbothioamide (ZTR) was designed and synthesized by thiosemicarbazone Schiff base as a specific complexes site strategy to achieve highly specific Cu2+ detection. The fluorescence of the probe ZTR solution fell dramatically when Cu2+ was added, and its appearance changed from dazzling blue to nearly colorless. The simple structure and readily available fluorescent probe provide a novel approach for the quantitative detection of Cu2+ in the linear range from 0 to 0.12 μM, with a detection limit down to 16 nM, and with high selectivity for Cu2+ over 15 other metal ions. Job’s plot analysis showed that probe ZTR and Cu2+ formed a 1:1 coordination complex. In addition, because of its low detection limits and fast response time, the created fluorescent molecule was effectively used to study the target ions on test paper strips and in water samples.))

A review on metallic carbides/phosphides embedded in N-doped porous carbon as highly efficiency electrocatalyst for hydrogen evolution reactions in alkaline medium

The designing of electrocatalyst to perform hydrogen evolution reaction (HER) in alkaline medium is presently a demanding pathway for sustainable production of hydrogen (H2) which can be generated from alkaline water electrolysis used in industries. Although a large number of electrocatalyst reported in literature have the tendency to exhibit superior HER performance in acidic medium, but the vaporization of acid electrolyte causes corrosion of the cell and resulted in contamination during the H2 production. The involvement of additional step during water dissociation process (volmer step) in alkaline medium could cause serious sluggish electrode kinetics and thus a hunt of new type of heterostructured electrocatalyst (to indue strong synergetic effect of the heterointerfaces) to outperform noble precious metals are under exploration. The development of earth abundant transition metal carbides/phosphides have been emerging recently because of their electronic structure/configuration are similar to that of platinum (Pt), leading to enhance the elecrocatalytic performance. A variety of metallic carbides/phosphides incorporated on porous materials are studied by researchers are faced difficulty in integration of single nanostructure unit to achieve HER activity in alkaline medium as same as that in acidic medium. The present review aims to provide comprehensive of heterostructured carbides/phosphides supported on N-doped porous carbon (NPC) for electrocatalytic efficiency for HER. We also discussed the influencing role of structure, codopants, and the porosity for lowering overpotentials. Finally, the challenges and the future goals for designing efficient electrocatalyst to provide promising HER for large scale applications are highlighted.

External electric field-assisted electronic restructuring of transition metal oxides derived from spent lithium-ion batteries to enhance persulfate activation

Discarded lithium-ion batteries contain abundant transition metal oxides, which benefit to persulfate activation. Inspired by electrocatalysis and the structural properties of the ternary lithium-ion battery cathode, we investigate the effect of external electric field polarization on the electronic structure reorganization behavior of NCM and the catalytic performance of peroxymonosulfate (PMS). Firstly, external electric field polarization promotes the gathering of Co and Ni. Secondly, the electric field modified waste NCM (E-PD@NCM) has 1.61 times higher degradation rate of SMX than the non-electric field modified waste NCM (PD@NCM). Meanwhile, electric field polarization increased the oxygen vacancy content in the spent NCM, and the abundant oxygen vacancies effectively restructured the electronic structure of E-PDNCM, further accelerating charge transfer and significantly improving the PMS activation efficiency. The catalytic mechanism analysis indicates that SO4•− and 1O2 play a dominant role in the degradation of pollutants. This study demonstrates the high catalytic performance of TMO through reorganization of the electronic structure and provides a new strategy to guide the design of other metal oxide nano-catalysts.

Bifunctional Catalysts with Morphology-Controllable Iron Sulfide Nanosheets for Overall Water Splitting

Engineering the morphology of naturally abundant transition metal sulfides is an effective strategy to improve their electrocatalytic activity. In this work, lumpy-, coral-, and flower-like Fe0.95S1.05 catalysts were successfully prepared using a one-pot solvothermal method through the decomposition of iron thiolato carbonyl complexes (Fe2S2(CO)6) in different solvents. Then, the structural and morphological characteristics of the nanomaterials were comprehensively investigated by a series of state-of-the-art techniques. The results showed that the formed flower-like Fe0.95S1.05 nanosheets had a high surface area of 63.7 m2 g−1 and a low contact angle of 15.4°, and a greater number of d orbitals of Fe2+ and Fe3+ overlapped on the surface. Correspondingly, this catalyst exhibited enhanced oxygen evolution reaction and hydrogen evolution reaction activities with a current density of 10 mA cm−2 at overpotentials of 280 and 345 mV, respectively, and these values were lower than those of lumpy- and coral-like Fe0.95S1.05. When flower-like Fe0.95S1.05 was assembled as the anode and cathode catalysts, overall water splitting efficiency was achieved at 1.68 V at 10 mA cm−2. This study provides a simple and low-cost approach for preparing efficient pyrrhotite FeS-based electrocatalysts for water splitting.

Perturbed iron biology in the prefrontal cortex of people with schizophrenia

Despite loss of grey matter volume and emergence of distinct cognitive deficits in young adults diagnosed with schizophrenia, current treatments for schizophrenia do not target disruptions in late maturational reshaping of the prefrontal cortex. Iron, the most abundant transition metal in the brain, is essential to brain development and function, but in excess, it can impair major neurotransmission systems and lead to lipid peroxidation, neuroinflammation and accelerated aging. However, analysis of cortical iron biology in schizophrenia has not been reported in modern literature. Using a combination of inductively coupled plasma-mass spectrometry and western blots, we quantified iron and its major-storage protein, ferritin, in post-mortem prefrontal cortex specimens obtained from three independent, well-characterised brain tissue resources. Compared to matched controls (n = 85), among schizophrenia cases (n = 86) we found elevated tissue iron, unlikely to be confounded by demographic and lifestyle variables, by duration, dose and type of antipsychotic medications used or by copper and zinc levels. We further observed a loss of physiologic age-dependent iron accumulation among people with schizophrenia, in that the iron level among cases was already high in young adulthood. Ferritin, which stores iron in a redox-inactive form, was paradoxically decreased in individuals with the disorder. Such iron-ferritin uncoupling could alter free, chemically reactive, tissue iron in key reasoning and planning areas of the young-adult schizophrenia cortex. Using a prediction model based on iron and ferritin, our data provide a pathophysiologic link between perturbed cortical iron biology and schizophrenia and indicate that achievement of optimal cortical iron homeostasis could offer a new therapeutic target.

Measuring Zn2+ binding to DNA and corresponding structural changes using circular dichroism and ICP-OES.

Zinc is the second most abundant transition metal on the body. While the nature of zinc binding to DNA remains unclear it is known that zinc binding causes measureable structural changes. It is not established whether the divalent zinc ions are specifically bound to a particular site within DNA or diffusively bound. By combining CD (circular dichroism) spectroscopy measurements of DNA with ICP-OES (Inductively coupled plasma optical emission spectroscopy) measurements of ions binding to DNA, changes caused by the zinc binding can be monitored. CD spectroscopy measurements oversee changes in the DNA structure, while ICP-OES can quantify the amount of zinc ions bound to the phosphate groups of DNA. This will provide important insight on the effects of transition metal divalent ion binding on DNA structure.

Improving the Catalytic Performance of the Hydrogen Evolution Reaction of α-MoB2 via Rational Doping by Transition Metal Elements.

Abundant transition metal borides are emerging as promising electrochemical hydrogen evolution reaction (HER) catalysts which have a potential to substitute noble metals. Those containing graphene-like (flat) boron layers, such as α-MoB2, are particularly promising and their performance can be further enhanced via doping by the second metal. In order to understand intrinsic effect of doping and rationalize selection of dopants, we employ density functional theory (DFT) calculations to study substitutional doping of α-MoB2 by transition metals as a route towards systematic improvement of intrinsic catalytic activity towards HER. We calculated thermodynamic stability of various transition metal elements to select metals which form a stable ternary phase with α-MoB2 . We inspected surface stability of dopants and assessed catalytic activity of doped surface through hydrogen binding free energy at various hydrogen coverages. We calculated the reaction barriers and pathways for the Tafel step of HER for the most promising dopants. The results highlight iron as the best dopant, simultaneously lowering the reaction barrier of the Tafel step while having suitable thermodynamic stability within MoB2 lattice.

Computational insights into the iron-catalyzed magnesium-mediated hydroformylation of alkynes

Iron is one of the most abundant transition metals in the earth's crust. It has attracted a lot of attention due to its low toxicity, bio-compatibility, and high natural abundance. Iron-catalyzed hydroamination, hydroalkoxylation, hydrocarboxylation, hydrosilylation, hydroboration, hydrophosphination, hydromagnesiation, and carbonylation reactions have therefore been developed over the past decades. However, despite many experimental and theoretical studies, a complete mechanistic understanding of iron-catalyzed hydrofunctionalisation at the molecular level has not yet been achieved. In this work, through density functional theory (DFT) calculations, we have shown the most feasible path for the hydroformylation of alkynes for an experimentally studied system. We have looked at the iron salt as a precatalyst without any external donor ligand, and the calculations revealed that hydrometalation followed by β-hydride elimination was favorable over the direct migration of the β-hydrogen to carbon. Furthermore, our calculations show that the solvent plays an important role in the hydromagnesiation reaction. Furthermore, we have employed an explicit solvent model, where the attachment of one molecule of solvent to the iron center was seen to stabilize the transition states significantly.

Dissolution of WO3 modified with IrOx overlayers during photoelectrochemical water splitting

AbstractWO3, an abundant transition metal semiconductor, is one of the most discussed materials to be used as a photoanode in photoelectrochemical water‐splitting devices. The photoelectrochemical properties, such as photoactivity and selectivity of WO3 in different electrolytes, are already well understood. However, the understanding of stability, one of the most important properties for utilization in a commercial device, is still in the early stages. In this work, a photoelectrochemical scanning flow cell coupled to an inductively coupled plasma mass spectrometer is applied to determine the influence of co‐catalyst overlayers on photoanode stability. Spray‐coated WO3 photoanodes are used as a model system. Iridium is applied to the electrodes by atomic layer deposition in controlled layer thickness, as determined by ellipsometry and x‐ray photoelectron spectroscopy. Photoactivity of the iridium‐modified WO3 photoanodes decreases with increasing iridium layer thickness. Partial blocking of the WO3 surface by iridium is proposed as the main cause of the decreased photoelectrochemical performance. On the other hand, the stability of WO3 is notably increased even in the presence of the thinnest investigated iridium overlayer. Based on our findings, we provide a set of strategies to synthesize nanocomposite photoelectrodes simultaneously possessing high photoelectrochemical activity and photostability.

Palladium-anchored donor-flexible pyridylidene amide (PYA) electrocatalysts for CO2 reduction.

The conversion of CO2 into CO as a substitute for processing fossil fuels to produce hydrocarbons is a sustainable, carbon neutral energy technology. However, the electrochemical reduction of CO2 into a synthesis gas (CO and H2) at a commercial scale requires an efficient electrocatalyst. In this perspective, a series of six new palladium complexes with the general formula [Pd(L)(Y)]Y, where L is a donor-flexible PYA, N2,N6-bis(1-ethylpyridin-4(1H)-ylidene)pyridine-2,6-dicarboxamide, N2,N6-bis(1-butylpyridin-4(1H)-ylidene)pyridine-2,6-dicarboxamide, or N2,N6-bis(1-benzylpyridin-4(1H)-ylidene)pyridine-2,6-dicarboxamide, and Y = OAc or Cl-, were utilized as active electrocatalysts for the conversion of CO2 into a synthesis gas. These palladium(ii) pincer complexes were synthesized from their respective H-PYA proligands using 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU) or sodium acetate as a base. All the compounds were successfully characterized by various physical methods of analysis, such as proton and carbon NMR, FTIR, CHN, and single-crystal XRD. The redox chemistry of palladium complexes toward carbon dioxide activation suggested an evident CO2 interaction with each Pd(ii) catalyst. [Pd(N2,N6-bis(1-ethylpyridin-4(1H)-ylidene)pyridine-2,6-dicarboxamide)(Cl)]Cl showed the best electrocatalytic activity for CO2 reduction into a synthesis gas under the acidic condition of trifluoracetic acid (TFA) with a minimum overpotential of 0.40 V, a maximum turnover frequency (TOF) of 101 s-1, and 58% FE of CO. This pincer scaffold could be stereochemically tuned with the exploration of earth abundant first row transition metals for further improvements in the CO2 reduction chemistry.