Triisobutylaluminium-promoted formation of lanthanide hydrides.

Discrete lanthanide(III) isobutylaluminates Ln[N(SiMe 3 ) 2 ](HAliBu 3 )(AliBu 4 ) (Ln = La, Pr, Nd) are obtained from Ln[N(SiMe 3 ) 2 ] 3 and triisobutylaluminium (TIBA). Nd[N(SiMe 3 ) 2 ](HAliBu 3 )(AliBu 4 ) reacts with crown ether to give the ion pair [Nd(18-c-6){N(SiMe 3 ) 2 }(HAliBu 3 )][AliBu 4 ], featuring a strong Nd-H interaction in the solid state. The equimolar reaction of La[N(SiMe 3 ) 2 ](HAliBu 3 )(AliBu 4 ) with fluorene resulted in the concomitant formation of [(μ-fluorenyl) 3 La 2 (μ-H)(HAliBu 3 ) 2 ] and (fluorenyl) 2 La[N(SiMe 3 ) 2 ]. [(μ-Fluorenyl) 3 La 2 (μ-H)(HAliBu 3 ) 2 ] features fluorenyl ligands with a μ-η 6 :η 6 coordination around the hydrido-bridged dilanthanum core motif. The reported complexes are the first crystallographically characterized, ancillary ligand-free lanthanide(III) tetraisobutylaluminates, and display potential model systems for Ziegler-type polymerization catalysis.