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 Sc0 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(κ2-NO3)­(μ-OH)]­NO3}2 (2a), [(H2O)4Sc­(κ2-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 45Sc nuclear magnetic resonance spectroscopic studies.