Estimation of the Standard Enthalpy of Formation of Crystalline Alkali Metal Borates

A structure–property correlation has been developed, which makes it possible to choose the optimal values of the enthalpy of formation of alkali metal borates, for which, according to the data of various experimental works and reference publications, wide variations are observed. Using this correlation, the enthalpy of formation of unstudied alkali metal borates can be reasonably estimated. It has been found that the contribution of B 2 O 3 to the enthalpy of formation is the same not only for alkali metal borates but also for Ba, Ca, and Pb borates, for whose enthalpy of formation a structure–property correlation has also been established. This suggests the suitability of the obtained correlations for estimating the enthalpy of formation in the borate series, where the value is known only for one member of the series, as well as the possibility of estimating the enthalpy of formation of mixed borates of different metals.