Aqua species of beryllium

   We have already noted that there is a high tendency to form [Be(H₂O)₄]²⁺‏ in aqueous media. In ¹⁷O-enriched water, exchange between coordinated water and solvent is slow on the NMR spectroscopic timescale, permitting the nature of the hydrated ion to be established. The tetrahedral coordination sphere (Be-O = 162.0 pm) has been established in the solid state structure of [Be(H₂O)₄][O₂CC≡CCO₂] (Figure 1.1). The charge density of Be^2‏+ is high and solutions of beryllium salts are acidic.  Reaction showen in below is an over-simplistic representation of the dissociation, since various condensation processes occur and hydroxo-bridged species are also present.