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) A, b = 14.891(3) A, c = 12.030(1) A, alpha = 101.65(2) degrees, beta = 115.08(2) degrees, gamma = 97.66(1) degrees, V = 2110.8(2) A(3), Z = 1 (T = 288 K). The compound CL2 crystallizes in the triclinic space group P1, with a = 13.539(4) A, b = 14.755(2) A, c = 11.951(2) A, alpha = 101.70(1) degrees, beta = 115.11(1) degrees, gamma = 97.44(2) degrees, V = 2053.8(8) A(3), Z = 1 (T = 198 K). The formation of box-type structure is caused by steric hindrance between bulky substituents of the ligands.