Y. Nakamura et al., INTERACTION BETWEEN BENZENE AND NAPHTHALENOPHANE - IN THE GAS-PHASE AND THE CRYSTALLINE LATTICE, Liebigs Annalen, (8), 1997, pp. 1769-1776
The interaction between naphthalenophane 1 and another aromatic compou
nd in the gas phase was investigated by molecular orbital calculations
, mainly focusing on the arrangement of both aromatic compounds and th
e effect oi the substituents in the benzene ring. The X-ray crystallog
raphic analysis of some clathrates of 1 with an aromatic solvent was a
lso carried out in order to clarify the relationship between the gas a
nd condensed phases. The most stable arrangement calculated for a comp
lex of 1 and benzene or substituted benzene in the gas phase was found
to be the arrangement in which the edges of the two naphthalene rings
of 1 are directed to the face of the benzene ring. Such an arrangemen
t was also observed in the clathrate crystals, according to the X-ray
crystallographic analysis. This result suggests that the stable arrang
ement in the gas phase is probably maintained in solution, leading to
the same arrangement in the crystals. The order of stabilization of th
e clathrates with some substituted benzenes is in agreement with that
of the electron-donating ability of the functional group present in th
e benzene. A slight difference in the stabilization was observed betwe
en the complex with toluene and that with chlorobenzene, and such a di
fference is considered to affect the inclusion behavior of 1.