71Ga nuclear magnetic resonance investigation of aqueous gallium(III) and its hydrolysis

The 71Ga resonance line width of the aquagallium cation [Ga(H2O)6]3+ is shown to vary with pH, and to have a minimum value of 53 Hz in the presence of excess acid and provided that the gallium concentration is not greater than 22 mM. It is shown that the dependence of line width on pH is due to self‐hydrolysis of the cation and is consistent with the known value of the 1,1 hydrolysis constant of pK1,1 = 2.6.