Tris(bipyridine)iron(II) chloride

Tris(bipyridine)iron(II) chloride is the chloride salt of the coordination complex tris(bipyridine)iron(II), [Fe(C₁₀H₈N₂)₃]²⁺. It is a red solid. In contrast to tris(bipyridine)ruthenium(II), this iron complex is not a useful photosensitizer because its excited states relax too rapidly, a consequence of the primogenic effect.

Tris(bipyridine)iron(II) chloride

Identifiers
CAS Number	14751-83-8
3D model (JSmol)	Interactive image
ChemSpider	176367
PubChem CID	203609
InChI InChI=1S/3C10H8N2.2ClH.Fe/c3*1-3-7-11-9(5-1)10-6-2-4-8-12-10;;;/h3*1-8H;2*1H;/q;;;;;+2/p-2 Key: GBRPARYPGGYWHF-UHFFFAOYSA-L
SMILES [n+]12ccccc1c1cccc[n+1]1[Fe-4]234([n+]1ccccc1c1cccc[n+1]13)[n+]1ccccc1c1cccc[n+1]14.[Cl-].[Cl-]
Properties
Chemical formula	C30H24Cl2FeN6
Molar mass	595.31 g·mol−1
Appearance	red solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Tris(bipyridine)iron(II) chloride features an octahedral Fe(II) center bound to three bipyridine ligands. The complex has been isolated as salts with many anions.^[1]

Synthesis and reactions

The sulfate salt [Fe(bipy)₃]SO₄ is produced by combining ferrous sulfate with excess bipy in aqueous solution.^[2] This result illustrates the preference of Fe(II) for bipyridine vs water. The potentials for |[Fe(bipy)₃]^2+/3+ and [Fe(phen)₃]^2+/3+ are very similar.^[3]

Addition of cyanide to an aqueous solution of [Fe(bipy)₃]SO₄ precipitates Fe(bipy)₂(CN)₂.^[4]

Another reported synthetic approach for the synthesis of [Fe(bipy)₃]²⁺ involves the use of Iron(II) tetrafluoroborate as a precursor, combined with bipy in a precise stoichiometric ratio, in the solid state via mechanochemistry.^[5]

Related complexes

• Tris(o-phenanthroline)iron(II)