Syntheses and structures of mononuclear lutetium imido complexes with very short Lu-N bonds

The reaction of 1,3-bis( 2,6-diisopropylphenyl)imidazolin-2-imine (Im(Dipp)NH) with trimethylsilylmethyllithium and anhydrous lutetium trichloride affords the imido complex [LuCl2( ImN(Dipp))( THF)(3)] (1), which, on further reaction with dipotassium cyclooctatetraenide, K-2( C8H8), leads to the half-sandwich cyclooctatetraenyl complex [(mu(8)-C8H8) Lu(ImN(Dipp))( THF)(2)]; both complexes contain very short Lu-N bond lengths, which are shorter than any previously reported Lu-N distances.