INCLUSION CRYSTALS FROM NAPHTHALENOPHANES IN AROMATIC SOLVENTS

The inclusion crystal formation of naphthalenophanes with polar substi tuents was investigated in comparison with that of naphthalenophanes w ithout substituents. In contrast with the latters, the naphthalenophan e with two methoxycarbonyl groups (2a) afforded rather stable inclusio n crystals, in which the benzene molecules were accommodated in the ch annels along the b-axis. The formation of the channels is ascribable t o the strong intermolecular dipole-dipole interaction between the meth oxycarbonyl groups. On the other hand, no inclusion crystals were obta ined from the naphthalenophane with four ethoxycarbonyl groups (2b).