Lanthanide enolates

Divalent organolanthanide complexes can also initiate MMA polymerization. A divalent lanthanide complex, as a single-electron transfer reagent, can readily react with the monomer to generate a radical anion species, which subsequently couples into a bimetallic trivalent lanthanide enolate intermediate, which is the active center. Therefore, divalent organolanthanide complexes serve as bisinitiators for MMA polymerization [160]. 

A C—C coupling reaction has been observed in the reaction of LnCp 2CH(SiMe3)2 (Ln = La, Ce) with enolizable ketones such as acetone or 3-pentanone. A plausible mechanism for this reaction, which proceeds with elimination of one mole of CH2(SiMe3)2, invokes formation of the lanthanide enolate 70, coordination of a second molecule of ketone to the metal centre to give 71 and C-C coupling with the enolate to yield the final product (equation 49). 

Metal enolates found varied application in chemical analysis. An outstanding group are certain lanthanide enolates used as shift reagents in NMR spectroscopy. The analytical methods discussed in Section IV are based on formation of a metal enolate for separation, detection, identification and determination of metal ions or the use of a metal enolate as ancillary reagent to improve analytical quality. Of special relevance in analytical chemistry are the metal /3-diketonates, M(dik) , derivatived from deprotonated /3-diketones (dikH),... 

Lanthanide enolates carrying lipophilic groups can be used as ionophores to fabricate Cl ISE membranes. Thus, electrodes with a membrane incorporating into pvc a lantanide chelate such as 61 or 62a-c, an anion excluder such as NaBPlu and a plasticizer (dioctyl sebacate, dioctyl adipate, dibutyl phthalate, dioctyl phthalate or tributyl phosphate) have... 

Lanthanide enolates as nuclear magnetic resonance shift reagents... 

Lanthanide enolates as nnclear magnetic resonance shift reagents 801... 

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