h6 ‐Arene(halogenidoaluminato)lanthanoid(III) complexes: Synthesis, characterization and catalytic activity for isoprene polymerization

η 6 -Arene(iodido-/bromido-aluminato)lanthanoid(III) complexes, [Ln(η -C H 5 Me)(AlI 4 ) 3 ] [ Ln = La ( 1 ), Ce 2 Nd (Gd) ); C Me toluene], -1,3,5)(AlI [Ln Pr 7 8 Sm 9 Gd 10 -1,3,5 mesitylene], and Me)(AlBr 11 12 13 )] were prepared by reactions of aluminium triiodide or tribromide with the corresponding lanthanoid metals 1,2-diiodoethane 1,2-dibromoethane in an arene (toluene mesitylene) solution (molar ratio: 6:2:3). The first X-ray crystal structures arene(iodidoaluminato)lanthanoid(III) complexes are reported. atom is coordinated –arene three chelating κ(I, I′)-tetraiodidoaluminate ligands. tetrabromidoaluminate have similar structures. pre-catalyst was treated AlR (R i Bu) to give [Nd(η R) species situ, which then tested for catalytic activity towards isoprene polymerization. Although resulting polyisoprene had a desirable high cis- 1,4 content, catalyst performance well below known best performing systems indicates that iodidoaluminates least favourable halogenidoaluminatolanthanoid(III) complexes.