Five new cryptands have been prepared by a 2: l cyclocondensation of an a, o-dihalide with an u, w-diamine. In some cases, other producta, such as bh (aza-l2-crown-4) ligands and producta of a 4 2 cyclocondensation, were isolated also. The structurea of the cryptands and bis (aza-crow& of the same molecular weight were established after careful analysis by NMR and X-ray spectroscopy and a few independent syntheses of the bis (aza-crown) ...