Organolanthanide chemistry

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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:

  • They are far more air- and water-sensitive and are often pyrophoric.
  • Chemistry in the 0 oxidation state is far more limited. In fact, their electropositive nature makes their organometallic compounds more likely to be ionic.
  • They form no stable carbonyls at room temperature; organolanthanide carbonyl compounds have been observed only in argon matrices, and decompose when heated to 40 K.

σ-Bonded Complexes

Metal-carbon σ bonds are found in alkyls of the lanthanide elements such as [LnMe6]3- and Ln[CH(SiMe3)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:

2Ln + 3Ph2Hg + 6THF → 2LnPh3(THF)3 + Hg (Ln = Ho, Er, Tm, Lu).

π-Bonded Complexes

Cyclopentadienyl complexes are known for all lanthanides. All, barring tris(cyclopentadienyl)promethium(III) (Pm(Cp)3) can be produced by the following reaction scheme:

3 Na[Cp] + MCl3 → M[Cp]3 + 3 NaCl

Pm(Cp)3 can be produced by the following reaction:

2 PmCl3 + 3 Be[Cp]2 → 3 BeCl2 + 2 Pm[Cp]3

These compounds are of limited use and academic interest. [1]

See also

CH He
CLi CBe CB CC CN CO CF Ne
CNa CMg CAl CSi CP CS CCl CAr
CK CCa CSc CTi CV CCr CMn CFe CCo CNi CCu CZn CGa CGe CAs CSe CBr CKr
CRb CSr CY CZr CNb CMo CTc CRu CRh CPd CAg CCd CIn CSn CSb CTe CI CXe
CCs CBa CHf CTa CW CRe COs CIr CPt CAu CHg CTl CPb CBi CPo CAt Rn
Fr CRa Rf Db Sg Bh Hs Mt Ds Rg Cn Uut Fl Uup Lv Uus Uuo
↓
CLa CCe CPr CNd CPm CSm CEu CGd CTb CDy CHo CEr CTm CYb CLu
Ac CTh CPa CU CNp CPu CAm CCm CBk CCf CEs Fm Md No Lr
Chemical bonds to carbon
Core organic chemistry Many uses in chemistry
Academic research, but no widespread use Bond unknown

References

  1. ↑ J. J. Zuckerman (17 September 2009). Inorganic Reactions and Methods, The Formation of Bonds to Elements of Group IVB (C, Si, Ge, Sn, Pb). John Wiley & Sons. ISBN 978-0-470-14547-0. Retrieved 28 July 2013. 
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