Dichlorotetrakis(pyridine)iron(II)

Dichlorotetrakis(pyridine)iron(II) is the coordination complex with the formula FeCl₂(pyridine)₄. A yellow solid, it is a prominent example of a transition metal pyridine complex. It is used as an anhydrous precursor to other iron complexes and catalysts.^[1] According to X-ray crystallography, the chloride ligands are mutually trans. The complex has a high spin configuration. A monohydrate as well as several related complexes are known, e.g. CoCl₂(pyridine)₄ and NiCl₂(pyridine)₄.^[2] It is prepared by treating ferrous chloride with an excess of pyridine.^[3]

Dichlorotetrakis(pyridine)iron(II)

Names
Other names Tetra(pyridine)iron dichloride
Identifiers
CAS Number	15138-92-8 monohydrate
3D model (JSmol)	Interactive image
ChemSpider	21169983
PubChem CID	15809771
InChI InChI=1S/4C5H5N.2ClH.Fe/c4*1-2-4-6-5-3-1;;;/h4*1-5H;2*1H;/q;;;;;;+2/p-2 Key: KVQSAWIBLUAVAB-UHFFFAOYSA-L
SMILES C1=CC=NC=C1.C1=CC=NC=C1.C1=CC=NC=C1.C1=CC=NC=C1.Cl[Fe]Cl
Properties
Chemical formula	C20H20Cl2FeN4
Molar mass	443.15 g·mol−1
Appearance	yellow solid
Density	1.351 g/cm3
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references