Ammonium bis (oxalato)dioxovanadate(V)

Ammonium bis(oxalato)dioxovanadate(V)
Names:	ammonium bis(oxalato)dioxovanadate(V)
Formula:	(NH4)3[VO2(C2O4)2] (anhydrous) (NH4)3[VO2(C2O4)2] · 2H2O (dihydrate)
Molar mass:	313.092 g/mol (anhydrous) 349.122 g/mol (dihydrate)
Density:	1.667 g/cm3 (dihydrate)
Crystal system:	orthorhombic (dihydrate) a=11.098 Å, b=15.714 Å, c=7.979 Åα=90°, β=90°, γ=90°
Color:	yellow
Decomposition point:	125 °C398.15 K <br />257 °F <br />716.67 °R <br /> (dihydrate) 200 °C473.15 K <br />392 °F <br />851.67 °R <br /> (anhydrous)
Stability:	stable (dihydrate)
Hardness:	relatively strong

Description

Organic coordination complex, salt of ammonium, transitional metal vanadium and organic oxalic acid. From water solutions crystallizes as dihydrate.

Precursors

Reaction between ammonium vanadate, oxalic acid and ammonium oxalate

Chemical equation:

NH₄VO₃ + H₂C₂O₄ + (NH₄)₂C₂O₄ = (NH₄)₃[VO₂(C₂O₄)₂] + H₂O

For preparation of 100.00g of ammonium bis(oxalato)dioxovanadate(V) dihydrate

dihydrate

anhydrous

а 33.51g of ammonium vanadate, 25.79g of oxalic acid and 35.55g of ammonium oxalate is required.

All the compounds are combined in 1:1:1 molar ratio as aqueous solution. A deep yellow solution quickly formed. Some drops of H2O2 can be added to prevent reduction. This solution is then evaporated at room temperature to form large crystals. Darkening is caused by reduction and is not a big deal.

Storage conditions

Keep in its original form or under several layers of varnish at average humidity and room temperature. Do not keep crystals near heaters.

Solubility

Highly soluble in water.

Gallery

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  Some large single crystalsAmmonium bis(oxalato)dioxovanadate(V), Vicky Silviana, personal BlogVicky SilvianaPersonal Blog

Sources

• Hoard, J. L.; Scheidt, W. Robert; Tsai, Chun-Che Stereochemistry of dioxovanadium(V) complexes. I. Crystal and molecular structure of triammonium bis(oxalato)dioxovanadate(V) dihydrate
• Sathyanarayana, D. N.; Patel, C. C. Studies of Ammonium Dioxovanadium(V) Bisoxalate Dihydrate

Navigation

Vanadium compounds
Vanadium(II)-ammonium sulfate ((NH4)2V(SO4)2) • Vanadium(III)-ammonium sulfate (NH4V(SO4)2)

Oxalates
Salts	Ammonium oxalate ((NH4)2C2O4) • Cobalt(II) oxalate (CoC2O4) • Diglycine oxalate ((NH2CH2COOH)3 · H2C2O4) • Neodymium oxalate (Nd2(C2O4)3) • Oxalic acid (H2C2O4) • Sodium oxalate (Na2C2O4) • Tris(ethylenediamine)nickel oxalate ([Ni(H2NCH2CH2NH2)3]C2O4)
Dioxalatocuprates	Ammonium dioxalatocuprate(II) ((NH4)2[Cu(C2O4)2]) • Potassium dioxalatocuprate(II) (K2[Cu(C2O4)2]) • Sodium dioxalatocuprate(II) (Na2[Cu(C2O4)2])
Trioxalatoaluminates	Potassium trioxalatoaluminate (K3[Al(C2O4)3]) • Sodium trioxalatoaluminate (Na3[Al(C2O4)3])
Trioxalatochromates	Potassium trioxalatochromate(III) (K3[Cr(C2O4)3]) • Sodium trioxalatochromate(III) (Ns3[Cr(C2O4)3])
Trioxalatocobaltates	Potassium trioxalatocobaltate(III) (K3[Co(C2O4)3])
Trioxalatoferrates	Ammonium trioxalatoferrate(III) ((NH4)3[Fe(C2O4)3]) • Lithium trioxalatoferrate(III) (Li3[Fe(C2O4)3]) • Lithium trioxalatoferrate(III)-chloride (Li4[Fe(C2O4)3]Cl) Potassium trioxalatoferrate(III) (K3[Fe(C2O4)3]) • Potassium-sodium trioxalatoferrate(III) (K5Na[Fe(C2O4)3]2) • Sodium trioxalatoferrate(III) (Na3[Fe(C2O4)3])
Ethers	Dimethyl oxalate ((CH3)2C2O4)