Vanadyl oxalate

• CAS: 15500-04-6
• Catalog Number: ACM15500046
• Category: Main Products
• Molecular Weight: 154.96
• Molecular Formula: C2O5V
• Synonyms: Oxalic acid oxovanadium(IV) salt
• IUPAC Name: oxalic acid;oxovanadium
• Canonical SMILES: C(=O)(C(=O)O)O.O=[V]
• InChI: InChI=1S/C2H₂O4.O.V/c3-1(4)2(5)6;;/h(H,3,4)(H,5,6)
• InChI Key: OGUCKKLSDGRKSH-UHFFFAOYSA-N
• Appearance: Blue crystalline powder
• Complexity: 86.6
• Covalently-Bonded Unit Count: 2
• EC Number: 604-991-6
• Exact Mass: 156.93418g/mol
• Formal Charge: 0
• H-Bond Acceptor: 5
• H-Bond Donor: 2
• Heavy Atom Count: 8
• Monoisotopic Mass: 156.93418g/mol
• Rotatable Bond Count: 0

Case Study

Zinc Nitrate/Vanadyl Oxalate Catalytic System for Molecular Oxygen Catalytic Oxidation of α-Hydroxy Esters

Ju, Yongwei, et al. Molecules, 2019, 24(7), 1281.

A catalytic system consisting of zinc nitrate/vanadyl oxalate [Zn(NO3)2/VOC2O4] can be used for molecular oxygen catalytic oxidation of α-hydroxy esters to prepare high value-added α-keto esters.
· Catalytic Reaction Procedure
In a typical catalytic oxidation of α-hydroxy esters, in 25 mL autoclave, placed 5 mmol of α-hydroxy esters, VOC2O4·2H2O (0.25 mmol), Zn(NO3)2·6H2O (0.25 mmol) and CH3CN (5 mL) into a solution. The oxygen was introduced in at 0.2 MPa. This was stirred at 80 °C for 1.5 hours. The product was filtered and analyzed by gas chromatography after the reaction.
· Catalytic Mechanism
First, VOC2O4 and Zn(NO3)2 behaved in oxidative mode. With water, this reaction gave off nitric acid (HNO3) gas. Afterwards, vanadium (IV) species from VOC2O4 were converted to vanadium (V) species by the HNO3 gas which oxidized α-hydroxy esters into α-keto esters to create new vanadium (IV) species. It is this catalytic activity that uses HNO3 produced to kick-start and sustain the vanadium (IV)/vanadium (V) redox cycle, and the NOx redox cycle is powered by molecular oxygen.

How Does Vanadyl Oxalate Inhibit Hot Dip Galvanized Steel Corrosion?

Gao, Zhiqiang, et al. Corrosion Science, 2018, 142, 153-160.

This work studied corrosion inhibition of vanadyl oxalate (VOC2O4) on hot dip galvanized (HDG) steel in 5wt% NaCl by galvanic corrosion and XPS. The galvanic corrosion method using the split cell technique can separate the anodic and cathodic reactions, allowing the effect of V(IV) on each reaction to be considered independently. The following conclusions can be obtained:
· Anodic and cathodic reactions were partially separated through the selection of electrode materials or by differential aeration.
· The introduction of V(IV) solution greatly decreased the oxygen reduction reaction (ORR) rate on both Cu and HDG cathodes during galvanic coupling experiments.
· Adding V(IV) solution to the anode side of all split cells did not significantly affect the galvanic current.
· When V(IV) solution was injected into the cathode side, a current spike was observed, indicating the reduction of V(IV) to V(III).
· V(IV) mitigates the corrosion of HDG through a process involving electrochemical reduction.

Thermal analysis, EPR and XPS studies of vanadyl oxalate behavior

Matta, J., et al. Journal of thermal analysis and calorimetry 66.3 (2001): 717-727.

The thermal decomposition of vanadyl oxalate supported on CeO2 in a dry air stream was analyzed in the range of room temperature to 350°C by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). TG and DSC results show the presence of cerium oxalate and vanadium (V) oxalate after impregnation of CeO solid with vanadyl oxalate solution. The latter compound appears to be attached to cerium (III) of the partially reduced CeO phase. This result was confirmed by electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) techniques.
The solid Cerium dioxide was calcined at 500°C for four hours under a dry air stream. Subsequently, for the classical impregnation method, vanadyl oxalate VOC2O4 solution was added to ceria to prepare xV10Ce samples with different V/Ce atomic ratios (x=1.08, 1.67, 2.73, and 5.06). After filtration, these freshly prepared solids were dried at 100 °C and then analyzed by X-ray diffraction techniques. Only XRD lines corresponding to the CeO phase were observed. No traces of any other crystalline phase were found on all samples. Thermal analysis measurements were performed using a microbalance equipped device. Simultaneous thermogravimetric and differential scanning calorimetry (TG-DSC) curves were obtained when the dried xV10Ce samples were heated from room temperature to 350 °C at a rate of 5 °C min under air flow (75 mL/min).

Vanadyl oxalate for galvanic corrosion study

Gao, Zhiqiang, et al. Corrosion Science 142 (2018): 153-160.

The corrosion inhibition mechanism of vanadyl oxalate on hot-dip galvanized steel was investigated by galvanic corrosion method and XPS. Partial separation of electrode reactions was achieved using a split cell design. Injection of vanadyl oxalate solution into the cathode side of the split cell significantly reduced the galvanic current. V(IV) inhibits oxygen reduction by the mechanism of V(IV) reduction to V(III) and formation of a V(III) layer on the cathode. Since the V(III) layer occupies the active sites for oxygen reduction, V(IV) acts as a cathodic inhibitor.
The material used in the study was HDG steel plate. The HDG steel plate was cut into 2×4 cm specimens and then ultrasonically cleaned in ethanol. The base electrolyte was 5wt% NaCl solution. The V(IV) solution was prepared by dissolving 85.5 mM Vanadyl oxalate VOC2O4 in 5wt% NaCl solution and adjusting the prepared pH to the range of 5.0 to 5.5 with phosphoric acid. The split cell electrodes in the two isolated cells were connected by a salt bridge. There is a circular hole with an area of 1 cm at the bottom of the cell tank, and a rubber ring is used to prevent leakage of the electrolyte. Therefore, the exposed area of each electrode in the electrolyte is 1 cm2. The current and potential of the galvanic couple are measured in zero resistance ammeter (ZRA) mode. It is worth noting that the potential drop of the system is negligible due to the low ohmic drop determined by the small current and the good conductivity of the electrolyte. The saturated calomel reference electrode (SCE) is used to monitor the potential of the anode electrode.

Selective catalytic oxidation of α-hydroxy esters to α-ketoesters by vanadyl oxalate

Ju, Yongwei, et al. Molecules 24.7 (2019): 1281.

The selective oxidation of α-hydroxy esters is one of the important methods for preparing high value-added α-ketoesters. It is reported that an efficient catalytic system consisting of zinc nitrate/vanadyl oxalate can be used for the catalytic oxidation of α-hydroxy esters by molecular oxygen. Under mild reaction conditions, DL-mandelic acid methyl ester or lactic acid methyl ester can be easily obtained with a conversion rate of up to 99% and high selectivity for their corresponding α-ketoesters. The zinc nitrate/vanadyl oxalate combination exhibits higher catalytic activity, and different nitric oxide gases are detected by in situ attenuated total reflection infrared (ATR-IR) spectroscopy. This work contributes to the further development of efficient aerobic oxidation under mild reaction conditions.
In the typical procedure for catalytic oxidation of α-hydroxy esters, α-hydroxy esters (5 mmol), vanadyl oxalate (0.25 mmol), zinc nitrate (0.25 mmol) and CH3CN (5 mL) were placed in an autoclave (25 mL). After the reaction was complete, the obtained mixture was filtered and the conversion rate and selectivity were determined based on the area normalization method by gas chromatography. The product was verified by GC-MS, NMR and ATR-IR.

Effects on bovine lactoferrin studied with vanadyl oxalate

Carmichael, Alasdair, and James S. Vincent. (1979): 349-352.

Lactoferrin, while similar in its ability to bind metals to serum transferrin in the physiological pH range, has a markedly different ability to bind vanadyl at low pH. There are 2 strong binding sites, requiring one mole of oxalate per mole of VO2+ bound at pH 4.2. In addition there are 4 relatively weak nonspecific binding sites. The ESR of divanadyl lactoferrin in pH 4.2 acetate buffer does not indicate that the 2 strong binding sites are unequal near room temperature. When diferric lactoferrin with oxalate as anion is treated with excess vanadyl oxalate, the ESR spectrum of bound vanadyl lactoferrin appears and the spectrum of free vanadyl decreases. No splitting of the vanadyl ESR line is observed at 10°C. However, the 77 K spectrum does show 2 conformations of the same 2 sites or 2 conformations of different sites with similar binding properties at room temperature. The use of other metals provides most of the evidence for non-equivalent lactoferrin binding sites.
When apoptolactoferrin was titrated with a solution of vanadyl oxalate in acetate buffer at pH 4.2, the ESR spectral intensity of bound vanadyl showed distinct endpoints corresponding to 1.8:1 mol VO2+ to protein. The peak height of the bound vanadyl ESR line, the MI = -7/2 line, was measured with 5 X 10^-4 M vanadyl oxalate added to apoptolactoferrin in 0.01 M (pH 4.2) buffer. The peak height of this line adjusted for the spectrometer gain closely approximates the relative concentration of bound vanadyl over the experimental concentration range.

Custom Q&A

What is the molecular formula of vanadyl oxalate?

The molecular formula of vanadyl oxalate is C2H2O5V.

What are the synonyms of vanadyl oxalate?

The synonyms of vanadyl oxalate are oxalic acid;oxovanadium, Vanadium oxyoxalate, and DTXSID201287100.

What is the molecular weight of vanadyl oxalate?

The molecular weight of vanadyl oxalate is 156.98 g/mol.

What is the IUPAC name of vanadyl oxalate?

The IUPAC name of vanadyl oxalate is oxalic acid;oxovanadium.

What is the InChI of vanadyl oxalate?

The InChI of vanadyl oxalate is InChI=1S/C2H2O4.O.V/c3-1(4)2(5)6;;/h(H,3,4)(H,5,6);;.

What is the InChIKey of vanadyl oxalate?

The InChIKey of vanadyl oxalate is OGUCKKLSDGRKSH-UHFFFAOYSA-N.

What are the other identifiers of vanadyl oxalate?

The other identifiers of vanadyl oxalate include CAS number 15500-04-6, European Community (EC) Number 604-991-6, and DSSTox Substance ID DTXSID201287100.

What is the hydrogen bond donor count of vanadyl oxalate?

The hydrogen bond donor count of vanadyl oxalate is 2.

What is the hydrogen bond acceptor count of vanadyl oxalate?

The hydrogen bond acceptor count of vanadyl oxalate is 5.

Is vanadyl oxalate a covalently-bonded compound?

Yes, vanadyl oxalate is a covalently-bonded compound.