Intramolecular polarization of the dative B–O bond in the donor–acceptor complexes of 1-boraadamantanes with tetrahydrofuran

The X-ray diffraction studies and B3LYP/6-311G^* calculations of the complexes of 1-boraadamantane and 4-bromo-1-boraadamantane with THF have revealed that the introduction of a halogen atom results in a shortening of the B−O bond due to intramolecular polarization.