Synthesis and inclusion properties of macrocyclic polyethers containing phosphonic groups

Three novel polyether macrocycles II-IV bearing phosphonic groups have been synthesised in satisfactory yields. Macrocycle II was found to form a 1:1 inclusion compound with cyclohexane and thus was easily isolated from the reaction mixture as a clathrate. The crystal and molecular structure of the cyclohexane solvate has been determined by single crystal X-ray analyses and refined to an R of 0.028 for 3199 reflection. The compound is monoclinic, space group P2(1)/n with a = 15.886(6) Angstrom, b = 11.657(5) Angstrom, c = 18.621 (6) Angstrom, beta = 90.12(3)degrees, Z = 2. The whole molecule exhibits a great deal of disorder and the different conformations were modelled as consisting of two different primary conformers with population approximately 60:40.