1009332-10-8Relevant articles and documents
Strategies for the synthesis of lanthanum dialkyl complexes with monoanionic ancillary ligands
Bambirra, Sergio,Perazzolo, Francesca,Boot, Steven J.,Sciarone, Timo J.J.,Meetsma, Auke,Hessen, Bart
, p. 704 - 712 (2009/01/30)
The synthesis of lanthanum dialkyl complexes with monoanionic ancillary ligands [L]- is pursued by three different strategies: (a) in situ peralkylation of LaBr3(THF)4 with 3 equiv of LiCH 2SiMe3 followed by reaction with LH; (b) reaction of isolated La(CH2Ph)3(THF)3with LH; (c) stepwise salt metathesis on LaBr3(THF)4. Methods (a) and (b) generally work well for triazacyclononane-amide and amidinate ligands, but are unsuitable for the sterically demanding β-diketiminate [HC(MeC-NAr) 2]- (Ar = 2,6-iPr2C6H3) due to its high affinity for the Li cation and the sluggish reactivity of the diketimine. Nevertheless, the β-diketiminate lanthanum dibenzyl complex [HC(MeCNAr)2]-La(CH2Ph)2(THF) could be obtained by first reacting LaBr3(THF)4 with K[HC(MeCNAr) 2] to form [HC(MeCNAr)2]LaBr2(THF)2 and subsequent reaction of this dibromide complex with 2 equiv of PhCH 2K. When this reaction mixture is warmed, the product decomposes by H-abstraction from one of the diketiminate methyl groups and ligand redistribution, forming the coordination polymer {[μ-η2: η1-ArNC(Me)CHC(CH2)NAr]2La[K(THF) 4]}∞.