Clathrate inclusion behaviour of thia - substituted diquinoline host molecules

Continuing our search for new compounds which function as lattice inclusion hosts, the thia-substituted diquinoline derivatives 5 and 6 have been synthesised and the X-ray structures of (5)6?(CH3OH) and (6)?(benzene) determined. A literature survey on the thioether–1,3-peri aromatic hydrogen interaction reveals that this is reasonably common, but neither crystal structure contains this motif despite expectations from our earlier work on the oxygenated analogues 3 and 4. It is also significant that the commonly observed edge–edge aryl C–H...N dimer motif is absent in (5)6?(CH3OH) and only present in (6)?(benzene) as an ineffectual, longrange contact. Instead, opposite host enantiomers in (5)6?(CH3OH) are linked through aza–1,3-peri aromatic hydrogen interactions, and the prevalence of this motif in the literature is also surveyed. Six molecules of 5 surround the methanol guest which is disordered on a 3̄ site. The benzene molecules in (6)?(benzene) assemble by means of aryl edge–face interactions to produce parallel columns. This arrangement is the same as part of the lattice structure in solid benzene.