Borophosphonate cages as element-blocks: Ab initio calculation of the electronic structure of a simple borophosphonate, [HPO₃BH]₄, and synthesis of two novel borophosphonate cages with polymerizable groups

Ab initio calculations based on the density functional theory (DFT) were performed with respect to the structure and orbital energy values of a simple [HPO₃BH]₄ cage, and the results were discussed with structural parameters reported for other borophosphonate cages as well as with the calculated orbital energy values of its silsesquioxane analogue, [HSiO_1.5]₈. In addition, two novel borophosphonate cages capable of use as element-block monomers were prepared from two boronic acid-t-butylphosphonic acid reactions.