Crystal Structures of Chiral Ionophores: Bis(9,9′-spirobifluorene)-26-crown-4 and -32-crown-6

The X-ray crystal structures of bis(9,9′-spirobifluorene)-26-crown-4βbenzene solvate (monoclinic, a = 15.47 Å, b 11.265 Å, c = 15.220 Å, β = 91.54°, space group C2) and bis(9,9′-spirobifluorene)-32-crown-6·dichloromethane solvate (tetragonal, a = 20.958 Å, c = 11.779 Å, space group P4₁2₁2) are described. Both compounds act as enantioselective ionophores for α-aminoalcohols.