:1,1'-Dilithioferrocene
{{Chembox
| ImageFile = FcLi2.svg
| ImageSize = 110 px
| ImageAlt =
| IUPACName = 1,1'-Dilithioferrocene
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 33272-09-2
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID = 9238543
| PubChem = 11063390
| StdInChI=1S/2C5H4.Fe.2Li/c2*1-2-4-5-3-1;;;/h2*1-4H;;;/q2*-1;;2*+1
| StdInChIKey = CWUATGTYNYDRDF-UHFFFAOYSA-N
| SMILES = [Li+].[Li+].[CH]1[CH][CH][C-][CH]1.[CH]1[CH][CH][C-][CH]1.[Fe]
}}
|Section2={{Chembox Properties
| C=10|H=8|Fe=1|Li=2
| MolarMass =
| Appearance = orange solid
| Density =
| MeltingPt =
| BoilingPt =
| Solubility = }}
|Section3={{Chembox Hazards
| MainHazards = pyrophoric
| FlashPt =
| AutoignitionPt = }}
}}
1,1'-Dilithioferrocene is the organoiron compound with the formula Fe(C5H4Li)2. It is exclusively generated and isolated as a solvate, using either ether or tertiary amine ligands bound to the lithium centers. Regardless of the solvate, dilithioferrocene is used commonly to prepare derivatives of ferrocene.
Synthesis and reactions
Treatment of ferrocene with butyl lithium gives 1,1'-dilithioferrocene, regardless of the stoichiometry (monolithioferrocene requires special conditions for its preparation). Typically the lithiation reaction is conducted in the presence of tetramethylethylenediamine (tmeda). The adduct [Fe(C5H4Li)2]3(tmeda)2 has been crystallized from such solutions.{{cite journal |doi=10.1021/om00131a023|title=The Structure of the 3:2 Adduct of 1,1'-Dilithioferrocene with Tetramethylethylenediamine|year=1985|last1=Butler|first1=Ian R.|last2=Cullen|first2=William R.|last3=Ni|first3=Jijin|last4=Rettig|first4=Stephen J.|journal=Organometallics|volume=4|issue=12|pages=2196–2201}} Recrystallization of this adduct from thf gives [Fe(C5H4Li)2]3(thf)6.{{cite journal |doi=10.1021/om800765a|title=Comparison of Doubly Lithiated, Magnesiated, and Zincated Ferrocenes: [Fe(η5-C5H4)2]2Zn2(tmeda)2, the First Example of a [1.1]Ferrocenophane with Bridging First-Row Transition Metal Atoms|year=2008|last1=Perucha|first1=Alejandro Sánchez|last2=Heilmann-Brohl|first2=Julia|last3=Bolte|first3= Michael|last4=Lerner|first4=Hans-Wolfram|last5=Wagner|first5=Matthias|journal=Organometallics|volume=27|issue=23|pages=6170–6177}}
1,1'-Dilithioferrocene reacts with a variety of electrophiles to afford disubstituted derivatives of ferrocene. These electrophiles include S8 (to give 1,1'-ferrocenetrisulfide), chlorophosphines, and chlorosilanes.{{cite journal|first1=David E.|last1= Herbert |first2=Ulrich F. J.|last2= Mayer |first3=Ian |last3=Manners |title=Strained Metallocenophanes and Related Organometallic Rings Containing pi-Hydrocarbon Ligands and Transition-Metal Centers|journal= Angew. Chem. Int. Ed. |year=2007|volume =46|pages= 5060–5081|doi=10.1002/anie.200604409|pmid= 17587203 |issue=27}}
The diphosphine ligand 1,1'-bis(diphenylphosphino)ferrocene (dppf) is prepared by treating dilithioferrocene with chlorodiphenylphosphine.
Monolithioferrocene
The reaction of ferrocene with one equivalent of butyllithium mainly affords dilithioferrocene. Monolithioferrocene can be obtained using tert-butyllithium.{{cite journal |doi=10.1016/S0022-328X(01)00743-4|title=Synthesis, Structural Characterization and 57Fe-Mössbauer Spectra of Ferrocenylhexasilanes|year=2001|last1=Rautz|first1=Hermann|last2=Stüger|first2=Harald|last3=Kickelbick|first3=Guido|last4=Pietzsch|first4=Claus|journal=Journal of Organometallic Chemistry|volume=627|issue=2|pages=167–178}}
References
{{Cyclopentadienide complexes}}
{{DEFAULTSORT:Dilithioferrocene, 1,1'-}}