Crystal and supramolecular structures of complexes of BF3NH3 and BH3NH3 with 18-crown-6
Abstract
The macrocyclic polyether 18-crown-6 (C12H24O6) readily forms crystalline 1 : 1 complexes with the adducts BF3NH3 and BH3NH3. Crystals of the solvates BF3NH3·C12H24O6·CH2Cl2 and BH3NH3·C12H24O6·MeOH were suitable for X-ray crystallographic investigation. In both cases, the crystal structures reveal that 18-crown-6 adopts an all-gauche conformation with pseudo D3d symmetry in which the intermolecular N–H ⋯ O hydrogen-bonding interactions between the macrocyclic polyether and the adducts are associated directly with the triangle of oxygen atoms on the complexing face of the crown.