Organolanthanide chemistry is the field of chemistry that studies compounds with a lanthanide-to-carbon bond. Organolanthanide compounds are different from their organotransition metal analogues in the following ways:
Metal-carbon σ bonds are found in alkyls of the lanthanide elements such as [LnMe6]3− and Ln[CH(SiMe3)2]3. Methyllithium dissolved in THF reacts in stoichiometric ratio with LnCl3 (Ln = Y, La) to yield Ln(CH3)3 probably contaminated with LiCl.
If a chelating agent (L-L), such as tetramethylethylenediamine (tmed or tmeda) or 1,2-dimethoxyethane (dme) is mixed with MCl3 and CH3Li in THF, this forms [Li(tmed)]3[M(CH3)6] and [Li(dme)]3[M(CH3)6].
Certain powdered lanthanides react with diphenylmercury in THF to yield octahedral complexes:
Cyclopentadienyl complexes, including several lanthanocenes, are known for all lanthanides. All, barring tris(cyclopentadienyl)promethium(III) (Pm(Cp)3), can be produced by the following reaction scheme:
Pm(Cp)3 can be produced by the following reaction:
These compounds are of limited use and academic interest.