Lanthanide complex with trialkyl

Alternatively, and this procedure is preferred for the lanthanoid complexes [135], the imidazolium salt can be deprotonated in situ and reacted with a suitable trialkyl lanthanide or reacted without deprotonation with an anionic tetraalkyl lanthanide complex (see Figure 4.63). 

Lanthanide trialkyl and triaryl complexes are relatively unstable compared with lanthanide n-complexes because of their high coordination unsaturation. Thus trialkyl lanthanide complexes... 

The most convenient method for the synthesis of lanthanide dialkyl complexes is the alkane elimination reaction of lanthanide trialkyl complexes with a monoanionic preligand (L H) (Equation 8.15). The monoanionic preligands, which have tunable steric and electronic features, are favored for modifying the stability and reactivity of the complexes. Various bulky substituted cyclopentadienyl [4] and non-cyclopentadienyl derivatives have been used as the spectator ligands. The most common types of monoanionic non-cyclopentadienyl ancillary ligands are summarized in Figure 8.10 [36 8]. 

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