New Complexes of Zirconium(IV) and Hafnium(IV) with Heteroscorpionate Ligands and the Hydrolysis of Such Complexes To Give a Zirconium Cluster^#

A series of zirconium and hafnium heteroscorpionate complexes have been prepared by the reaction of MCl4 (M = Zr, Hf) with the compounds [{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] (the latter with the prior addition of BunLi). Under the appropriate experimental conditions, mononuclear complexes, namely, [MCl3(κ3-bdmpzx)] [x = a, M = Zr (1), Hf (2); x = dta, M = Zr (3), Hf (4); x = e, M = Zr (5), Hf (6)], and dinuclear complexes, namely, [{MCl2(μ-OH)(κ3-bdmpzx)}2] [x = a, M = Zr (7), Hf (8); x = dta, M = Zr (9); x = e, M = Zr (10)], were isolated. A family of alkoxide-containing complexes of the general formula [ZrCl2(κ3-bdmpzx)(OR)] [x = a, R = Me (11), Et (12), iPr (13), tBu (14); x = dta, R = Me (15), Et (16), iPr (17), tBu (18); x = e, R = Me (19), Et (20), iPr (21), tBu (22)] was also prepared. Complexes 11−14 underwent an interesting hydrolysis process to give the cluster complex [Zr6(μ3-OH)8(OH)8(κ2-bdmpza)8] (23). The structures of these complexes have been determined by spectroscopic methods, and the X-ray crystal structures of 7, 8, and 23 were also established.