PREPARATION AND CATION COMPLEXING PROPERTIES OF SOME MACROPOLYCYCLIC LIGANDS

Five new cryptands have been prepared by a 2:1 cyclocondensation of an alpha,omega-dihalide with an alpha,omega-diamine. In some cases, other products, such as bis(aza-12-crown-4) ligands and products of a 4:2 cyclocondensation, were isolated also. The structures of the cryptands and bis(aza-crown)s of the game molecular weight were established after careful analysis by C-13 NMR and X-ray spectroscopy and a few independent syntheses of the bis(aza-crown) ethers. A new TLC test has been developed to distinguish between the cryptands and the bis(aza-crown)s. Log K values for the interaction of two cryptands, each containing two propylene bridges in one arm, with various cations were determined. The results show a much weaker interaction of the cryptands containing two propylene bridges with various cations than that for the corresponding cryptands with only ethylene bridges. The most stable complexes of these new propylene-containing cryptands were those involving Ba2+ and Sr2+ ions. X-ray analyses of three cryptands, each of which has the [18]N2O4 macrocycle as part of its structure, show different organizations for the ring heteroatoms.