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 (<b>1</b>). Compound <b>1</b> 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 (<b>2a</b>), [(H₂O)₄Sc­(κ²-NO₃)₂]­NO₃·H₂O (<b>2b</b>) (at reflux temperatures), {6­[H]­[Sc­(μ-PO₄)­(PO₄)]₆}_<i>n</i> (<b>3</b>), and [H]­[Sc­(μ₃-SO₄)₂]·2H₂O (<b>4a</b>). Additional organosulfonic acid derivatives were investigated, including tosylic acid (H-OTs) to yield {[(H₂O)₄Sc­(OTs)₂]­OTs}·2H₂O (<b>4b</b>) in H₂O and [(DMSO)₃Sc­(OTs)₃] (<b>4c</b>) in dimethyl sulfoxide and triflic acid (H-OTf) to form [Sc­(H₂O)₈]­OTf₃ (<b>4d</b>). Other organic acid modifications of <b>1</b> were also investigated, and the final structures were determined to be {([(H₂O)₂Sc­(μ-OAc)₂]­Cl)₆}_<i>n</i> (<b>5</b>) from acetic acid (H-OAc) and [Sc­(μ-TFA)₃Sc­(μ-TFA)₃]_<i>n</i> (<b>6</b>) 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