Vanadium Centers Research Articles

Cyclopentadienone Vanadium(I) Complex: Synthesis, Red/Ox Activity, and Application to Catalytic Transfer Hydrogenation

Cyclopentadienone late transition metal complexes have exhibited various catalytic transformation and elementary reactions by transferring electrons from the metal to ligand, the so-called metal–ligand cooperation mechanism. Herein, we report a cyclopentadienone low-valent early transition metal, a vanadium(I), complex. The obtained complex furnished the most extended C═O bond length among all of the analogous CpO metal complexes, showing a substantial degree of metal-to-ligand electron transfer. The red/ox activity of the vanadium center in the cyclopentadienone V(I) complex was confirmed upon the addition of the proton source to yield the hydroxycyclopentadienyl V(III) complex. The system was applied to catalytic transfer hydrogenation of carbonyl compounds, indicating the possible application of the red/ox of the early transition metals in metal–ligand cooperative organic transformations.

Hybrid Molecular Magnets with Lanthanide- and Countercation-Mediated Interfacial Electron Transfer between Phthalocyanine and Polyoxovanadate.

A series of {V12}-nuclearity polyoxovanadate cages covalently functionalized with one or sandwiched by two phthalocyaninato (Pc) lanthanide (Ln) moieties via V-O-Ln bonds were prepared and fully characterized for paramagnetic Ln = SmIII-ErIII and diamagnetic Ln = LuIII, including YIII. The LnPc-functionalized {V12O32} cages with fully oxidized vanadium centers in the ground state were isolated as (nBu4N)3[HV12O32Cl(LnPc)] and (nBu4N)2[HV12O32Cl(LnPc)2] compounds. As corroborated by a combined experimental (EPR, DC and AC SQUID, laser photolysis transient absorption spectroscopy, and electrochemistry) and computational (DFT, MD, and model Hamiltonian approach) methods, the compounds feature intra- and intermolecular electron transfer that is responsible for a partial reduction at V(3d) centers from VV to VIV in the solid state and at high sample concentrations. The effects are generally Ln dependent and are clearly demonstrated for the (nBu4N)3[HV12O32Cl(LnPc)] representative with Ln = LuIII or DyIII. Intramolecular charge transfer takes place for Ln = LuIII and occurs from a Pc ligand via the Ln center to the {V12O32} core of the same molecule, whereas for Ln = DyIII, only intermolecular charge transfer is allowed, which is realized from Pc in one molecule to the {V12O32} core of another molecule usually via the nBu4N+ countercation. For all Ln but DyIII, two of these phenomena may be present in different proportions. Besides, it is demonstrated that (nBu4N)3[HV12O32Cl(DyPc)] is a field-induced single molecule magnet with a maximal relaxation time of the order 10-3 s. The obtained results open up the way to further exploration and fine-tuning of these three modular molecular nanocomposites regarding tailoring and control of their Ln-dependent charge-separated states (induced by intramolecular transfer) and relaxation dynamics as well as of electron hopping between molecules. This should enable us to realize ultra-sensitive polyoxometalate powered quasi-superconductors, sensors, and data storage/processing materials for quantum technologies and neuromorphic computing.

Coumarin-Ensembled Vanadium(V) Compounds and Their Affinity Studies Toward Biological Thiols Probed by Fluorescence Spectroscopy.

Fluorescence spectroscopic studies of a pair of new oxido-vanadium(V) compounds with biological thiols, such as homocysteine (Hcy), cysteine (Cys), and glutathione (GSH), have been investigated in this article. Despite notable progress in vanadium-thiol chemistry, no attention has been paid to exploring vanadium-based optical probes to study their interaction with biothiols. For this purpose, two oxido-vanadium(V) compounds, 1 and 2, have been prepared involving a tridentate ONO donor-based luminescent coumarin-derived ligand. Single crystal X-ray diffraction analysis, NMR (1 H, 13 C, and 51 V) spectroscopy, XPS, and DFT calculations have been used to establish their identities. The vanadium center in these compounds has a distorted octahedral environment. In compound 2, a methanol molecule is coordinated to the vanadium(V) center in the trans position of the terminal oxido moiety. The latter exerts a strong trans-labilizing influence on the coordinating methanol. Both 1 and 2 are weakly fluorescent. Photophysical investigations of the vanadium complexes in aqueous media at physiological pH (7.4) in the presence of various biothiols and amino acids showed significant fluorescence enhancement (83-fold) of the vanadium complexes, specifically with Hcy. The specific affinity of the complexes for Hcy remained unchanged even in the presence of other biothiols and amino acids. Kinetic investigation reveals pseudo-first order behavior of the compound with Hcy. Mechanistic studies have manifested that Hcy-induced reduction triggers the decomplexation of the vanadium compound, followed by hydrolysis and subsequent cyclization. Time-correlated single photon counting suggested that the radiative rate constant (kr ) of 1 and 2 in the presence of Hcy serves as the prime factor for the fluorescence enhancement of the medium. Compound 1 has been tested efficiently for Hcy measurement in blood plasma rendering it suitable for practical applications.

Reversible Conversion of Disulfide/Dithiolate Occurring at a Vanadium(IV) Center: A Biomimetic System for Redox Exchange in Vanabin.

Ascidians use a class of cysteine-rich proteins generally referred to as vanabins to reduce vanadium ions, one of the many biological processes that involve the redox conversion between disulfide and dithiolate mediated by transition-metal ions. To further understand the nature of disulfide/dithiolate exchange facilitated by a vanadium center, we report herein a six-coordinate non-oxido VIV complex containing an unbound disulfide moiety, [VIV(PS3″)(PS1″S-S)] (1) (PS3″ = [P(C6H3-3-Me3Si-2-S)3]3-, where PS1″S-S is a disulfide form of PS3″). Complex 1 is obtained from a reaction of previously reported [VV(PS3″)(PS2″SH)] (2) (PS2″SH = [P(C6H3-3-Me3Si-2-SH)(C6H3-3-Me3Si-2-S)2] with TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidin-1-yl)oxyl) via hydrogen atom transfer. Importantly, complex 1 can be reduced by two electrons to form an eight-coordinate VIV complex, [VIV(PS3″)2]2- (4). The reaction can be reversed through a two-electron oxidation process to regenerate complex 1. The redox pathways both proceed through a common intermediate, [V(PS3″)2]- (3), that has been previously reported as a resonance form of VV-dithiolate and a VIV-(thiolate)(thiyl-radical) species. This work demonstrates an unprecedented example of reversible disulfide/dithiolate interconversion mediated by a VIV center, as well as provides insights into understanding the function of VV reductases in vanabins.

Vanadium complexes bearing the bulky bis(imino)pyridine ligands: Good thermal stability toward ethylene polymerization

Vanadium complexes with unsymmetric bulky ligands 2-[1-(2,6-dibenzhydryl-4-methylphenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridine (V1-V3) and symmetrical bulky ligand 2,6-bis(1-(2,6-dibenzhydryl-4-methylphenylimino)ethyl)pyridine (V4) were prepared and thoroughly characterized. Single crystals of V1 and V4 were further tested with X-ray single crystal diffraction to prove the molecular structures, and a distorted triangular biconical geometry was adopted around vanadium centers of V1 and V4. These vanadium complexes bearing bulky ligands displayed moderate to high catalytic activity (up to 24.0 × 106 g molV-1 h−1) toward ethylene polymerization when ethylaluminum sesquichloride was employed as a cocatalyst, affording moderate to ultrahigh molecular weight polyethylenes (18.7 × 104 to 176.9 × 104 g/mol). Compared with the classical bis(imino)pyridine vanadium complex VR, complex V3 demonstrated a long lifetime as well as excellent thermal stability. Furthermore, polyethylenes derived from complexes V1-V4 had significantly higher molecular weights at high temperatures.

H2 Evolution at a Reduced Hybrid Polyoxometalate and Its Vanadium-Oxo Derivative Used as Molecular Models for Reducible Metal Oxides.

We herein report our investigations on the use of a tris-silanol-decorated polyoxotungstate, [SbW9O33(tBuSiOH)3]3-, as a molecular support model to describe the coordination of an isolated vanadium atom at metal oxides, focusing on the reactivity of the reduced derivatives in the presence of protons. Accumulation of electrons and protons at an active site is a main feature associated with heterogeneous catalysts able to conduct the (oxy)dehydrogenation of alkanes or alcohols. Our results indicate that two-electron reduced derivatives release H2 upon protonation, a reaction that probably takes place at the polyoxotungstic framework rather than at the vanadium center.

Enhancing effect of vanadium releasing efficiently from lattice in black shale by thermal activation

With the increasing demand for vanadium, the extraction technology of vanadium from strategic black shale has been widely valued. Vanadium mainly exists in muscovite of shale, and the extraction of vanadium requires the consumption of a large amount of acid. In industry, thermal activation is usually used to promote the dissolution of vanadium from muscovite. But the enhancing effect of thermal activation for releasing vanadium from lattice is unclear. In this study, the phase transition of black shale after thermal activation was described. Then the difference in lattice dissolution and vanadium migration were analyzed by quantum chemical simulations. From the atomic level, thermal activation caused a lattice expansion of vanadium-bearing muscovite (VM) through dehydroxylation reaction. Moreover, thermal activation can promote the replacement of K+ by H+, the removal of structural oxygen of tetrahedron and the coordination reaction of F- with central vanadium of octahedron in the acid leaching process.

Methoxido‐Bridged Lacunary Heterocubane Oxidovanadium(IV) Cluster with Azo Ligands: Synthesis, X‐ray Structure, Magnetic Properties, and Antiproliferative Activity

AbstractThe new μ3‐methoxido bridged trinuclear vanadium(IV) complexes [VIV3O3(μ3‐OMe)(μ2‐OMe)3(L1,2)2] (1 and 2) have been synthesized using the azo ligands 1‐(2‐(thiazol‐2‐yl)diazenyl)naphthalene‐2‐ol (HL1) and 2‐(2‐(thiazol‐2‐yl)diazenyl)‐4‐methylphenol (HL2). X‐ray crystallography revealed a trinuclear structure with a lacunary heterocubane {(VO)3(μ3‐OMe)(μ2‐OMe)3}2+ core unit for complex 1, which contains a central μ3‐methoxido bridge. All three vanadium centers are in a slightly distorted octahedral coordination environment. Magnetic and theoretical studies reveal an antiferromagnetic coupling between the three vanadium(IV) centers within the triangular arrangement in 1. The complexes were also screened for in vitro cytotoxicity study against HeLa and HT‐29 cancer cell lines. The results indicated that both the complexes are cytotoxic but possess varying specificity towards different cell types.

Exploring the Ligand Functionality, Electronic Band Gaps, and Switching Characteristics of Single Wells–Dawson‐Type Polyoxometalates on Gold (Adv. Mater. Interfaces 21/2022)

Polyoxometalates Polyoxometalates (POMs) equipped with vanadium centers offer outstanding opportunities for the development of switchable molecularly functionalized surfaces for non-binary, beyond-CMOS memory chips. In article number 2200461, Maria Glöß, Silvia Karthäuser, Kirill Yu. Monakhov, and co-workers report a room-temperature, multistate resistive switch based on a V3-substituted Wells-Dawson-type POM structure. The lilac spheres are unswitched POMs, the yellow sphere is switched POM.

A High Potential Polyanion Cathode Material for Rechargeable Mg-Ion Batteries.

The development of Mg-ion batteries is hindered by the lack of cathode materials that allow facile and reversible Mg2+ intercalation at high potential. Herein, the authors present a polyanion cathode material of K2 (VO)2 (HPO4 )2 (C2 O4 )⋅4.5H2 O (KVPCH) for Mg-ion batteries. The inductive effect of polyanions ensures the high redox potential of the vanadium centers. In addition, the material contains structural water located between the layers. It helps with Mg2+ desolvation at the electrode-electrolyte interface and facilitates its diffusion in the structure, as confirmed by experimental analysis and theoretical calculations. Thanks to those factors, the KVPCH electrode presents excellent Mg storage capability at room temperature. It delivers 121 mAh g-1 capacity at 1C with a high average discharge potential of 0.16 V versus Ag/Ag+ (3.2 V vs Mg/Mg2+ ). A capacity retention of 87% is realized after 1500 cycles at 5C. A rocking-chair Mg-ion full cell is also demonstrated with the KVPCH cathode and a MoOx anode, which achieves 46 mAh g-1 capacity (based on the total active material mass of two electrodes). This work would bring effective paths for the design of cathode materials for Mg-ion batteries.

Tale of Three Molecular Nitrides: Mononuclear Vanadium (V) and (IV) Nitrides As Well As a Mixed-Valence Trivanadium Nitride Having a V3N4 Double-Diamond Core.

Transmetallation of [VCl3(THF)3] and [TlTptBu,Me] afforded [(TptBu,Me)VCl2] (1, TptBu,Me = hydro-tris(3-tert-butyl-5-methylpyrazol-1-yl)borate), which was reduced with KC8 to form a C3v symmetric VII complex, [(TptBu,Me)VCl] (2). Complex 1 has a high-spin (S = 1) ground state and displays rhombic high-frequency and -field electron paramagnetic resonance (HFEPR) spectra, while complex 2 has an S = 3/2 4A2 ground state observable by conventional EPR spectroscopy. Complex 1 reacts with NaN3 to form the VV nitride-azide complex [(TptBu,Me)V≡N(N3)] (3). A likely VIII azide intermediate en route to 3, [(TptBu,Me)VCl(N3)] (4), was isolated by reacting 1 with N3SiMe3. Complex 4 is thermally stable but reacts with NaN3 to form 3, implying a bis-azide intermediate, [(TptBu,Me)V(N3)2] (A), leading to 3. Reduction of 3 with KC8 furnishes a trinuclear and mixed-valent nitride, [{(TptBu,Me)V}2(μ4-VN4)] (5), conforming to a Robin-Day class I description. Complex 5 features a central vanadium ion supported only by bridging nitride ligands. Contrary to 1, complex 2 reacts with NaN3 to produce an azide-bridged dimer, [{(TptBu,Me)V}2(1,3-μ2-N3)2] (6), with two antiferromagnetically coupled high-spin VII ions. Complex 5 could be independently produced along with [(κ2-TptBu,Me)2V] upon photolysis of 6 in arene solvents. The putative {VIV≡N} intermediate, [(TptBu,Me)V≡N] (B), was intercepted by photolyzing 6 in a coordinating solvent, such as tetrahydrofuran (THF), yielding [(TptBu,Me)V≡N(THF)] (B-THF). In arene solvents, B-THF expels THF to afford 5 and [(κ2-TptBu,Me)2V]. A more stable adduct (B-OPPh3) was prepared by reacting B-THF with OPPh3. These adducts of B are the first neutral and mononuclear VIV nitride complexes to be isolated.

A Study of High Resistivity Semi-Insulating 4H-SiC Epilayers Formed via the Implantation of Germanium and Vanadium

A systematic germanium (Ge) and vanadium (V) study on 4H-SiC epitaxial layers is presented. Electrical results of TLM structures which were fabricated on these layers revealed that highly-doped Ge and V-implanted layers showed extremely low specific contact resistivity, down to 2 x 10-7 Ω.cm2. Current flow in the conducting state of Schottky barrier diodes has been successfully suppressed in some implanted layers, with highly V doped samples showing current density values of approximately 1 x 10-5 Acm-2 at 10 V. DLTS spectra reveal the presence of germanium and vanadium centers in the respective samples as well as novel peaks which are likely related to the formation of a novel GeN center.

Unveiling the role of C60-supported vanadium single atoms for catalytic overall water splitting

Designing efficient bifunctional catalysts that can catalyze overall water splitting to generate hydrogen—an attractive, environmentally friendly and renewable energy carrier—is tremendously important to combat the global warming and energy crisis. Here, we report an atomistic-level understanding of the overall water splitting mechanism, 2H2O → 2H2 + O2, mediated by C60-supported vanadium single atoms. Detailed reaction pathways are calculated, and key intermediates with nominal chemical formulas of C60V+(H2O)2 and C60V+O2 are characterized by infrared spectroscopy. When mediated by an isolated V+, the overall water splitting reaction stops due to geometric restrictions with end product V+(OH)2 or V+O(H2O), whereas it can proceed to complete a catalytic cycle in the presence of the C60-support. Our analyses reveal that the vanadium center undergoes several formal oxidation state changes resulting from the unique electron donating/accepting ability of the C60-support, acting as an “electron sponge,” additional to its role in facilitating the hydrogen transfer.

Theoretical Investigation by DFT and Molecular Docking of Synthesized Oxidovanadium(IV)-Based Imidazole Drug Complexes as Promising Anticancer Agents.

Vanadium compounds have been set in various fields as anticancer, anti-diabetic, anti-parasitic, anti-viral, and anti-bacterial agents. This study reports the synthesis and structural characterization of oxidovanadium(IV)-based imidazole drug complexes by the elemental analyzer, molar conductance, magnetic moment, spectroscopic techniques, as well as thermal analysis. The obtained geometries were studied theoretically using density functional theory (DFT) under the B3LYP level. The DNA-binding nature of the ligands and their synthesized complexes has been studied by the electronic absorption titrations method. The biological studies were carried with in-vivo assays and the molecular docking method. The EPR spectra asserted the geometry around the vanadium center to be a square pyramid for metal complexes. The geometries have been confirmed using DFT under the B3LYP level. Moreover, the quantum parameters proposed promising bioactivity of the oxidovanadium(IV) complexes. The results of the DNA-binding revealed that the investigated complexes bind to DNA via non-covalent mode, and the intrinsic binding constant (Kb) value for the [VO(SO4)(MNZ)2] H2O complex was promising, which was 2.0 × 106 M−1. Additionally, the cytotoxic activity of the synthesized complexes exhibited good inhibition toward both hepatocellular carcinoma (HepG-2) and human breast cancer (HCF-7) cell lines. The results of molecular docking displayed good correlations with experimental cytotoxicity findings. Therefore, these findings suggest that our synthesized complexes can be introduced as effective anticancer agents.

Mono Versus Dinuclear Vanadium(V) Complexes: Solvent Dependent Structural Versatility and Electro Syntheses of Mixed-Valence Oxovanadium(IV/V) Entities in Solution.

Two mononuclear oxidovanadium(V) complexes type of [VVO(L1)(OMe)(MeOH)] (1), [VVO(L2)(OMe)(MeOH)] (2) and two [V2O3]4+ core of μ-oxidodioxidodivanadium(V) complexes (L1)(O)VV–O–VV(O)(L1) (3) and (L2)(O)VV–O–VV(O)(L2) (4) and two complexes [VVO(L1)(8-Hq)] (5) and [VVO(L2)(8-Hq)] (6) incorporating 8-hydroxyquinoline (8-hq) as co-ligand have been reported where L1 [(E)-N′-(2-hydroxybenzylidene)cinnamohydrazide] and L2 [(2E,N′E)-N′-(2-hydroxybenzylidene)-3-(naphthalen-1-yl)acrylohydrazide] are the dianionic forms of the conjugated keto-imine functionalized substituted hydrazone ligands. The μ-oxidodioxidodivanadium complexes are generated upon switching the solvent from methanol to acetonitrile. The X-ray analysis showed octahedral geometry for the mononuclear complexes 1, 2 and 5 but oxido-bridged dinuclear complexes 3 and 4 formed penta-coordinated square-pyramidal geometry about metal atoms. Two mixed-valence species of type II, 3a and 4a, of general formulae (L)(O)VIV–O–VV(O)(L), are being generated upon constant potential electrolysis (CPE) of 3 and 4 respectively. Frozen solution EPR spectra have 13 hyperfine lines, revealing the unpaired electron is majorly localized on one of the two vanadium centres. All these complexes have been well characterized by physio-chemical techniques and the density functional theory (DFT) calculations were applied to obtain further insight into the electronic structure of this type of molecule. The oxidomethoxido complexes 1 and 2 were taken to investigate the catechol oxidase mimicking activity following the oxidation of 3,5-di-tert-butyl catechol (3,5-DTBC) to 3,5-di-tert-butyl benzoquinone (3,5-DTBQ).

Syntheses, spectral characterization and antidiabetic activities of oxidovanadium(V) complexes with bi-and tridentate ligands

Four new oxidovanadium(V) complexes [VO(L 1 )(Mol)] ( 1 ), [VO(L 2 )(Mol)] ( 2 ), [VO(L 3 )(Mol)] ( 3 ) and [VO(L 4 )(Mol)] ( 4 ) (where L 1 -L 4 = aroylhydrazones and Mol = maltol) have been synthesized with different ligands. The complexes have been characterized using microanalysis, spectral fab mass, UV-visible, electrochemical (cyclic voltammetry and differential pulse voltammetry), density functional theory calculations have been performed to predict the optimized geometry, global reactivity parameters and electron density. In these complexes, the d-d absorption band is not observed as being d 0 vanadium centres in these complexes. The electrochemical behaviour of these complexes are explored by cyclic voltammetry and differential pulse voltammetry (DPV). All complexes exhibit one electron transfer i.e., reduction of vanadium(V) to vanadium(IV). These complexes are screened for in vitro α-glucosidase and α-amylase inhibition study. Complex 3 has an interesting insulin-like activity.

Synthesis, characterization, DFT calculations, and catalytic epoxidation of two oxovanadium(IV) Schiff base complexes

The present paper reports the synthesis, characterization, and DFT calculations of two oxovanadium (IV) Schiff base complexes symbolized as VOL1 and VOL2, which prepared by the reaction of bivalent tridentate Schiff base ligands (E)-2-((5-chloro-2-hydroxybenzylidene)amino)acetic acid and (E)-2-((2-hydoxy-5-nitrobenzylidene)amino)acetic acid and VO(acac)2 as vanadium source. The Schiff base ligands and its oxovanadium (IV) complexes were characterized by the elemental analysis (C, H, N), FTIR, 1H NMR and 13C NMR, DFT calculations were performed to derive some of their molecular properties. Schiff base ligands coordinated to vanadium center via nitrogen from the azomethine group and one oxygen from the hydroxyl attached to the benzene ring and one oxygen from hydroxyl of carboxyl group. The catalytic activity of the two complexes were tested against cyclooctene and found that both complexes were highly effective and selective in optimized conditions when used as cyclooctene epoxidation catalysts with the conversion percentage of 91.85% (with VOL1) and 87.40% (with VOL2) at 78 °C within a period of ten hours. To understand the structural properties of the two complexes, the two complexes were well optimized at B3LYP/6-31G(d,p) level of theory, structural parameters such as electron affinity, global electrophilicity, global hardness, electronegativity, ionization potential, and electron chemical potential based on HOMO and LUMO energy values were calculated.

Synthesis, structure and catalytic activity of new oxovanadium(V) complexes with deferiprone and N,N-donor ligands

A pair of new water-soluble oxovanadium(V) complexes comprising of deferiprone (def) and N,N-donor ligands, 2,2ʹ-bipyridine (bpy) or 1,10-phenanthroline (phen), [VO2(def)(bpy)]⋅H2O (1) and [VO2(def)(phen)]⋅4H2O (2) were synthesized. The complexes were characterized by elemental analysis, spectral studies and single crystal X-ray diffraction analysis. The X-ray crystal structures of 1 and 2 reveal that both the complexes possess distorted octahedral coordination geometries with O4N2 coordination sphere around the vanadium center, and the deprotonated deferiprone occupying the equatorial plane. The complexes 1 and 2 efficiently catalyzed selective epoxidation of styrene with 30% H2O2 under ecologically sustainable organic solvent-free conditions, at ambient temperature. The catalysts afforded good styrene conversion and high TON value along with excellent epoxide selectivity (>99%). Recyclability of the catalysts at least up to three consecutive cycles without significant alteration in activity or selectivity, is an additional remarkable feature of the developed catalytic protocol.

Paramagnetic centers in chromium-doped Na-=SUB=-5-=/SUB=-AlF-=SUB=-2-=/SUB=-(PO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=- single crystal

The paramagnetic resonance of Na5AlF2(PO4)2 single crystals with chromium impurity was studied. The Cr3+ centers have been found to replace the triclinic Al3+ positions. In the local coordinate system, the spectra of these centers were described by the spin Hamiltonian of rhombic symmetry. In addition, vanadium centers and unidentified triclinic symmetry centers have been observed. Keywords: impurity ions, aluminum fluoride phosphate, paramagnetic resonance.

The targeted multi-electrons transfer for acetic acid and ethanol obtained with (n-Bu4N)3SVW11O40 and in synergetic catalysis in CO2 electroreduction

Electrocatalytic CO2 reduction (ECO2RR) is a very promising new energy technology for carbon capture, utilization and storage. The chemical inertness of CO2 makes its conversion needs to be driven by efficient catalysts. Polyoxometalate (POM) inhibits hydrogen evolution side reaction (HER) for ECO2RR via proton coupling in their reversible, stepwise multi-electron transfer reactions. In this work, indium and prepared (n-Bu4N)3SVW11O40 (SVW11) work as synergetic catalysis firstly for ECO2RR to acetic acid and ethanol with 67.4% and 19.4%, respectively. The provided electron transferred to vanadium center in SVW11 and In3+ leading to the activity of In recovered and HSVIVW11O403− formed, where the proton-coupled electron transfer step of VIV/V in SVW11 electrolyte promoted the process of ECO2RR. The isomerized POM effectively reducing the reaction overpotential and increasing the products selectivity also.