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A one-step method for the synthesis of new phenol-containing cryptands and cryptohemispherands by treating N,"-bis(methoxymethy1)diazacrowns with the appropriate bis-and trisphenols is reported. This method, based on a special Mannich reaction, gives cyclized products without the need for protecting groups and high dilution conditions. Unusually high yields of cryptohemisherands were realized using a relatively high concentration of the starting materials (50 mmol/ L) and in the absence of metal cations as template agents in the reaction mixture. These excellent yields can be explained by intramolecular hydrogen bonding which prevents polycondensation. This new method also allowed preparation of new phenol-containing cylindrical tricyclic ligands by first forming bisphenol-substituted diaza-18-crown-6 at 80 "C followed by its reaction with a second bis(methoxymethy1)-substituted diaza-18-crown-6 at 144 "C. Crystal structures of two cryptohemispherands are reported herein. A shorter internal distance between N and 0 atoms in 27 as compared to 6 (R = NOz, n = m = 2) indicates intramolecular hydrogen bonding in phenol-containing macrocycle 27.

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The first three representatives of the new family of oxacyclophanes incorporating two 2,7-dioxyfluorenone fragments, connected by [-CH(2)CH(2)O-](m) spacers (m=2-4), have been synthesized. The yield of the smallest oxacyclophane (m=2) is considerably higher with respect to the larger ones (m=3 and m=4), which are formed in comparable yields. Molecular modeling and NMR spectra analysis of the model compounds suggest that an essential difference in oxacyclophanes yields is caused by formation of quasi-cyclic intermediates, which are preorganized for macrocyclization owing to intramolecular pi-pi stacking interactions between the fluorenone units. The solid-state structures of these oxacyclophanes exhibit intra- and intermolecular pi-pi stacking interactions that dictate their rectangular shape in the fluorenone backbone and crystal packing of the molecules with the parallel or T-shape arrangement. The crystal packing in all cases is also sustained by weak C--HO hydrogen bonds. FAB mass spectral analysis of mixtures of the larger oxacyclophanes (m=3 and m=4) and a paraquat moiety revealed peaks corresponding to the loss of one and two PF(6) (-) counterions from the 1:1 complexes formed. However, no signals were observed for complexes of the paraquat moiety with the smaller oxacyclophane (m=2). Computer molecular modeling of complexes revealed a pseudorotaxane-like incorporation of the paraquat unit, sandwiched within a macrocyclic cavity between the almost parallel-aligned fluorenone rings of the larger oxacyclophanes (m=3 and m=4). In contrast to this, only external complexes of the smallest oxacyclophane (m=2) with a paraquat unit have been found in the energy window of 10 kcal mol(-1).

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