Structure of aqueous potassium metaborate solution

The structure of aqueous potassium metaborate solutions has been confirmed by X-ray scattering, Raman spectra and species distribution calculation. The optimized structure of B(OH)4− was obtained by density functional theory calculation. The hydration distance and hydration number of K+ in aqueous potassium metaborate solution were given by X-ray scattering. The B–O(H2O) distance in hydrated anion B(OH)4− were determined to be 0.37 nm with the hydration number of 2.3 per hydroxyl(–OH). The K–B distance of the contact ions KB(OH)40 was measured to be 0.34 nm.