First Complexes of Scandium and Yttrium with NNO and NNS Heteroscorpionate Ligands

The reaction of ScCl3(THF)3 or YCl3 in a 1:1 molar ratio under reflux for 8 h with [{Li(bdmpza)(H2O)}4] [bdmpza = bis(3,5-dimethylpyrazol-1-yl)acetate], [{Li(bdmpzdta)(H2O)}4] [bdmpzdta = bis(3,5-dimethylpyrazol-1-yl)dithioacetate], and (Hbdmpze) [bdmpze = 2,2-bis(3,5-dimethylpyrazol-1-yl)ethoxide] affords the corresponding complexes [MCl2((kappa)3-bdmpzx)(THF)] (x = a, M = Sc (1), Y (2); x = dta, M = Sc (3), Y (4); x = e, M = Sc (5), Y (6)). However, when the reaction was carried out for 1 h under reflux between ScCl3(THF)3 and [{Li(bdmpzdta)(H2O)}4], a new anionic complex [Li(THF)4][ScCl3((kappa)3bdmpzdta)] (7) was obtained. Reaction of [{Li(bdmpza)(H2O)}4] with YCl3 in a 2:1 molar ratio under reflux for 8 h gave the complex [YCl((kappa)3-bdmpza)2] (8). The same reaction, but with the lithium compound [{Li(bdmpzdta)(H2O)}4], led to the formation of an anionic complex [Li(THF)4][YCl3((kappa)3-bdmpzdta)] (9). The X-ray crystal structures of 7 and 9 were established. Finally, the addition of 1 equiv of [{Li(bdmpza)(H2O)}4] or [{Li(bdmpzdta)(H2O)}4] to a solution of YCl3 in THF under reflux, followed by the addition of 1 equiv of 1,10-phenanthroline, resulted in the formation of the corresponding complexes [YCl2((kappa)3-bdmpzx)(phen)] (x = a (10), x = dta (11)). These complexes are the first examples of group 3 metals stabilized by heteroscorpionate ligands. In addition, we have explored the reactivity of some of these complexes with alcohols and amides. For example, the direct reaction of [YCl2((kappa)3-bdmpza)(THF)] (2) with several alcohols gave the alkoxide complexes [YCl((kappa)3-bdmpza)(OR)] (R = Et (12), iPr (13)). Finally, the reaction between [ScCl2((kappa)3-bdmpzdta)(THF)] (3) or [Li(THF)4][ScCl3((kappa)3-bdmpzdta)] (7) and LiN(SiMe3)2·Et2O in 1:1 and 1:2 molar ratios gave rise to the complexes [ScCl((kappa)3-bdmpzdta){N(SiMe3)2}] (14) and [Sc((kappa)3-bdmpzdta){N(SiMe3)2}2] (15), respectively.