Copper(I) Ion Mediated Self-Organization of Molecular Rectangular Boxes from 1,2-Bis(2-pyridylethynyl)benzene Ligands with Bulky Substituents

The reaction of chiral 1,2-bis(2-pyridylethynyl)benzene ligands with
copper(I) ions in dichloromethane at room temperature gives rise
to the formation of molecular rectangular boxes in high yields.
The structures of these complexes were confirmed by X-ray
crystallographic analysis. The compound CL1 crystallizes in the
triclinic space group P1, with a = 13.707(4) Å, b = 14.891(3) Å,
c = 12.030(1) Å, α = 101.65(2)°, β = 115.08(2)°, γ = 97.66(1)°,
V = 2110.8(2) Å3, Z = 1 (T = 288 K). The compound CL2
crystallizes in the triclinic space group P1, with a = 13.539(4) Å,
b = 14.755(2) Å, c = 11.951(2) Å, α = 101.70(1)°, β =
115.11(1)°, γ = 97.44(2)°, V = 2053.8(8) Å3, Z = 1 (T = 198
K). The formation of box-type structure is caused by steric
hindrance between bulky substituents of the ligands.