Heterometallic Potassium Rare-Earth-Metal Allyl and Hydrido Complexes Stabilized by a Dianionic (NNNN)-Type Macrocyclic Ancillary Ligand

Abstract

The macrocyclic diamino diamine (1,7-Me2TACD)H2 (1,7-Me2TACD = 1,7-dimethyl-1,4,7,10-tetraazacyclododecane, 1,7-Me2[12]aneN4), reacted under propylene elimination with [Ln(η3-C3H5)3(diox)] (Ln = Y, La) to give the mono(allyl) complexes [(1,7-Me2TACD)Ln(η3-C3H5)]2 (Ln = Y (1a), La (1b)). A single-crystal X-ray diffraction study shows 1b to be a centrosymmetric dimer with lanthanum atoms bridged by one of the two amido nitrogen atoms. Complexes 1a,b were treated with 2 equiv of the potassium allyl KC3H5 to give the corresponding heterometallic allyl complexes [(1,7-Me2TACD)Ln(η3-C3H5)2K(THF)]n (Ln = Y (2a), La (2b)). A single-crystal X-ray diffraction study revealed that 2a,b are polymeric in the solid state with allyl ligands bridging the metal centers in addition to the presence of μ2-amido functions of the 1,7-Me2TACD ligand. Hydrogenolysis of the yttrium compound 2a with 1 bar of H2 led to the formation of the heterometallic Y4K2 hydrido complex [(1,7-Me2TACD)2Y2H3K(THF)2]2 (3a), which can also be synth...