Structural Properties of the Acidification Products of Scandium Hydroxy Chloride Hydrate

The structural properties of a series of scandium inorganic acid derivatives were determined. The reaction of Sc(0) with concentrated aqueous hydrochloric acid led to the isolation of [(H2O)5Sc(μ-OH)]24Cl·2H2O (1). Compound 1 was modified with a series of inorganic acids (i.e., HNO3, H3PO4, and H2SO4) at room temperature and found to form {[(H2O)4Sc(κ(2)-NO3)(μ-OH)]NO3}2 (2a), [(H2O)4Sc(κ(2)-NO3)2]NO3·H2O (2b) (at reflux temperatures), {6[H][Sc(μ-PO4)(PO4)]6}n (3), and [H][Sc(μ3-SO4)2]·2H2O (4a). Additional organosulfonic acid derivatives were investigated, including tosylic acid (H-OTs) to yield {[(H2O)4Sc(OTs)2]OTs}·2H2O (4b) in H2O and [(DMSO)3Sc(OTs)3] (4c) in dimethyl sulfoxide and triflic acid (H-OTf) to form [Sc(H2O)8]OTf3 (4d). Other organic acid modifications of 1 were also investigated, and the final structures were determined to be {([(H2O)2Sc(μ-OAc)2]Cl)6}n (5) from acetic acid (H-OAc) and [Sc(μ-TFA)3Sc(μ-TFA)3]n (6) from trifluoroacetic acid (H-TFA). In addition to single-crystal X-ray structures, the compounds were identified by solid-state and solution-state (45)Sc nuclear magnetic resonance spectroscopic studies.