Bora-Amidinate Complexes of Lanthanide(II) Metals

Reaction of (2-Me(2)N-alpha-Me(3)Si-benzyl)(2)Ln center dot(thf)(2) (Ln = Yb, Eu and Sm) with one equivalent of DIPP(H)N-BH-N(H)DIPP ((DIPP)NBN-H(2), DIPP = 2,6-iPr-phenyl) gave the first Ln(II) bora-amidinate complexes which crystallized in the presence of THF as (DIPP)NBN-Ln center dot(thf)(4). Although only the Sm and Eu complex crystallize isomorphic, all three show similar structures. The very small N-Ln-N' bite angles of 59.74(6)-63.28(9)degrees leave a large part of the metal coordination sphere available for neutral thf ligands