Structure of aqueous potassium pentaborate solution

Abstract The structure of aqueous potassium pentaborate solution has been confirmed by species distribution calculation, synchrotron X-ray scattering, density function theory calculation. The kinds of species and the transformation relationship were investigated by species distribution calculation. The radial distribution function and the structure parameters were given out by synchrotron X-ray scattering experiment. The hydration distance of K–O(H 2 O) is ∼0.294 nm with a average hydration number of 8.0. The B–O(H 2 O) distance in hydrated anion [B 3 O 3 (OH) 4 (H 2 O) n ] − were determined to be ∼0.37 nm with the hydration number of 4–5. The structure and interaction energy of the first hydration sphere of [K(H 2 O) n ] + and [B 3 O 3 (OH) 4 (H 2 O) n ] − were also studied by density functional theory calculation.