Coordination of 2,2‘-Bipyridyl and 1,10-Phenanthroline to Yttrium and Lanthanum Complexes Based on a Scorpionate Ligand

Reaction of yttrium and lanthanum trichloride with 1 equiv of sodium or potassium hydrotris(3,5-dimethylpyrazolyl)borate and 1 equiv of 2,2‘-bipyridine gives good yields of the complexes [MCl2(TpMe2)(C10H8N2)] (M = Y (1), La
(2)). The analogous compounds with 1,10-phenanthroline, [MCl2(TpMe2)(C12H8N2)] (M = Y (3), La (4)), have been
obtained by a similar procedure. The solid-state structures of 2−4 were determined by single-crystal X-ray diffraction
and revealed that the compounds are all seven-coordinate with capped octahedral geometry. In contrast, reaction
of yttrium trichloride with 1 equiv of sodium hydrotris(3,5-dimethylpyrazolyl)borate in the presence of 1 equiv of
neocuproine affords [YCl3(TpMe2)][Na(neoc)3)] (5). Compounds 1 and 2 provide an entry for the synthesis of complexes
containing the bipyridyl ligand in a radical anionic form or in a dianionic form. Reaction of 1 and 2 with an excess
of sodium amalgam gives [Y(TpMe2)(bipy)(THF)2] (6) and [La(TpMe2)2(bipy)] (7), respectively. The structures of both
compounds have been determined by X-ray crystallography. Compound 7 can be oxidized with iodine to give
[La(TpMe2)2(bipy)]I (8).