Synthesis and structures of new mixed-metal lanthanide/magnesium allyl complexes

Luis F. Sanchez-Barba, David L. Hughes, Simon M. Humphrey, Manfred Bochmann

Research output: Contribution to journalArticlepeer-review

42 Citations (Scopus)


The reaction of LnI3(THF)n (Ln = La, n = 4; Ln = Y, n = 3.5) with 3 equiv of allylMgI in THF/1,4-dioxane proceeds in moderate yields to give the unexpected mixed-metal complexes [Ln(?3-C3H5)3(µ-C4H8O2)·Mg(?1-C3H5)2(µ-C4H8O2)1.5]8 (Ln = La 1, Y 2). By contrast, samarium iodide gives a salt containing a new allyl-bridged anion, [Mg(THF)6][Sm2(?3-C3H5)6(µ-?3:?3-C3H5)]2·toluene (3), while neodymium iodide affords [Mg(THF)6][Nd(?3-C3H5)4]2·2THF (4) under the same reaction conditions. On reaction with a mild proton acid such as the diketimine 2-(2,6-diisopropylphenyl)amino-4-(2,6-diisopropylphenyl)imino-2-pentene, 3 is converted into [Mg(THF)6][Sm(?3-C3H5)4]2·2THF (5), alongside Sm(?3-C3H5)2{?3-HC(MeCNC6H3iPr2-2,6)2}. The solid-state structures of 1 and 2 contain distorted trigonal-bipyramidal lanthanide centers with three ?3-allyl ligands and distorted trigonal-bipyramidal magnesium centers with two ?1-bonded allyls. Both metal centers are connected by bridging 1,4-dioxane molecules building a planar polymeric network. By contrast, 3 and 5 consist of well-defined discrete ions. Complex 3 contains an unprecedented type of binuclear anion containing two samarium centers bridged by an ?3:?3-allyl ligand, while the anion in 5 has distorted tetrahedral geometry.
Original languageEnglish
Pages (from-to)5329-5334
Number of pages6
Issue number22
Publication statusPublished - 14 Sep 2005

Cite this