Xanthenolclathrates: structure, thermal stability, guest exchange and kinetics of desolvation

Abstract

A series of clathrates comprising the xanthenol host, 9-(4-methoxyphenyl)-9H-xanthen-9-ol, with a variety of aromatic guests displays similar structures in the space group P(−1). We have elucidated the structures of the inclusion compounds H·½G, where H is 9-(4-methoxyphenyl)-9H-xanthen-9-ol and G is benzene, o-, m- and p-xylene. The structures are isostructural with respect to the host and display consistent (Host)–OH⋯O–(Host) hydrogen bonding. The guests lie on a centre of inversion and with the exception of the symmetrical guests, benzene and p-xylene, are disordered. An interesting case arises with m-xylene, which is ordered at low temperature (113 K) with both the host and guest molecules in general positions. At a higher temperature (283 K) the inclusion compound with m-xylene fits the series. We have correlated the structures with their thermal stabilities, guest exchange and kinetics of desolvation.