Nature of peroxoborate species in aqueous solution: a study by boron-11 nuclear magnetic resonance and Raman spectroscopy

Abstract

The ¹¹B n.m.r. spectra of solutions of [B(OH)₄]^– or B(OH)₃(0.01–4 mol dm^–3) with H₂O₂(0.01–34 mol dm^–3) have been studied from pH 14 to 4. A number of peroxoborates have been identified, in particular [B(O₂H)_n(OH)_{4 –n}]^–(n= 0–4) and polymeric species including [B₂(O₂)₂(O₂H)_n(OH)_{4 –n}]^2–n= 0, 2, or 4). Raman spectra have been recorded for concentrated solutions {1–4 mol dm^–3[B(OH)₄]^–, 1–12 mol dm^–3 H₂O₂} and partial assignments proposed.