A new polytype of orthoboric acid, H₃BO₃-3<i>T</i>

Abstract

The crystal structure of H(3)BO(3)-3T, a new trigonal polytype of orthoboric acid, consists of sheets of hydrogen-bonded B(OH)(3) molecules similar to those found in the triclinic structure of orthoboric acid, H(3)BO(3)-2A. In each case, van der Waals forces connect the sheets. However, the stacking sequences of the sheets differ between the two polymorphs. In H(3)BO(3)-3T (space group P3(2)), the sheets are stacked in the repeating sequence ABC em leader, whereas in H(3)BO(3)-2A (space group P-1, the sheets are stacked in the repeating sequence AB em leader.