SYNTHESIS, CHARACTERIZATION, AND X-RAY STRUCTURE OF 1,2-BIS-CROWN-5-CALIX[4]ARENE - MODELING OF METAL COMPLEXATION

1,2-bis-crown-5-calix[4]arene (3) was prepared by reacting calix[4] arene (1) with tetraethylene glycol di-p-toluenesulphonate (2) in the presence of cesium carbonate in 9% yield. The X-ray structure of (3) was determined. Crystal data for C44H52O10 are as follows: monoclinic, space group P-2/c with a = 18.006(8) Angstrom, b = 10.680(4) Angstrom, c = 22.359(6) Angstrom, beta = 112.93(3)degrees, V = 3958(6) Angstrom 3, Z = 4, D-calc = 1.2 g cm(-3), the final R value is 0.11 for the 1851 observed reflections (I > 3 sigma(I)). The single crystal included two similar but slightly different molecules immobilized in a pinched-cone conformation with C-2 symmetry. The two enantiomorphous molecules were analyzed by molecular mechanics using the GenMol program to model the selective alkali-metal complexation.