Lithium tris(oxalato) ferrate chloride

Formula: Li₄[Fe(C₂O₄)₃]Cl·9H₂O

Double salt of lithium with two different anions: ferrioxalate [Fe(C₂O₄)₃]^3- and chlorice Cl^-. Also known as tetralithium iron(III) trioxalate chloride nonahydrate.

Lithium ferrioxalate alone forms tabular crystals, but when lithium chloride is added, they crystallize together, orming new structure.

Properties

• Crystal system: trigonal
• Crystal shape: straight triangular prisms. Very rare shape for a crystal.
• Color: bright green, characteristing for ferrioxalates.
• Stability on air: not stable, losing water eventually.

Preparation

To prepare this compound, make aqueous solution, containing stoichiometric amounts of lithium ferrioxalate (see preparation on its page) and lithium chloride. Equation is:

Li₃[Fe(C₂O₄)₃] + LiCl + 9H₂O = Li₄[Fe(C₂O₄)₃]Cl·9H₂O

Growing

As always, I used slow evaporation at room temperature to grow large crystals. Solubility of this material is quite high.

Safety

All oxalates are mildly toxic.

More photos

References

• Crystal structure and mössbauer study of tetralithium iron(III) trioxalate chloride nonahydrate