Two clathrates, (H)(THF)(2) and (H)(1,3-dioxolane)(2), where H is 1,4-bis[3-(9-anthryl)propen-1-on-3-yl]benzene, were shown to be isomorphic by means of X-ray diffraction studies. In spite of the structural similarity, their thermal behavior was considerably different. The difference can be explained in terms of intermolecular weak forces between the host and the guest, including CH/pi and O/pi interactions.