Structure and properties of hydrated complexes of methylphosphonic acids

The electronic structure and the geometry of the hydrated complexes of methylphosphonic acids were investigated by the Density Functional Theory Method (B3LYP functional with 6-31G∗∗ basis set). Molecular structures were found to coexist with their ion associates. The interconversion between the two forms involves the simultaneous transfer of two protons, a process with a low energy barrier.