Synthesis, crystal structure and characterization of alkali metal hydroxoantimonates

Several alkali metal hydroxoantimonates, K2[Sb(O)(OH)5], Na[Sb(OH)6], Cs[Sb(OH)6] and Cs2[Sb2(μ-O)2(OH)8] were isolated from aqueous solutions and characterized by single crystal and powder X-ray diffraction studies and by FTIR and thermal analysis. Crystal structures involving [Sb(O)(OH)5]2− were never anticipated before, and this is also the first disclosure of a dinuclear antimonate [Sb2(μ-O)2(OH)8]2−. Aqueous antimonate solutions of different pH were studied by high resolution electrospray mass spectrometry showing pH indifferent spectra and predominance of the mono and dinuclear antimonate species at pH 4–10.

Synthesis of Na, K and Cs hydroxoantimonates and their structures characterization by single crystal and powder X-ray diffractometry, and by FTIR are presented. The sodium antimonate aqueous solutions were studied by high resolution electrospray ionization mass spectrometry as a function of pH.Figure optionsDownload as PowerPoint slideHighlights
► Several alkali metal hydroxoantimonates were isolated and characterized.
► Aqueous antimonate solutions were studied by electrospray mass spectrometry.
► This is the first disclosure of a dinuclear antimonate [Sb2(μ-O)2(OH)8]2−.
► The predominance of the mono and dinuclear antimonate species at pH 4–10 was found.