Structural aspects of a commensurate tunnel inclusion compound of tri-ortho-thymotide containing 1,8-dibromooctane guest molecules

摘要

Structural properties of the solid inclusion compound formed between 1,8-dibromooctane and tri-ortho-thymotide (TOT) are reported.In contrast to the inclusion compounds formed between TOT and other long-chain #alpha#,#omega#-dihalogenoalkane guest molecules,the 1,8-dibromooctane/TOT inclusion compoound has a commesurate relationship between the host and guest subsystem. The structural properties of this inclusion compound have been investigated at ambient temperature (293 K) and 123 K using single crystal X-ray diffraction techniques.At both temperatures, the structure [space group P6_1(P6_5)] is based on a superstructure (with seven-fold increase in unit cell volume)or the standard type T-II host structure of TOT inclusion compounds. The superstucture represents a comparatively small distortion from the standard type T-II TOT host structure, and contains two independent types of tunnels (the central and non-central tunnels). At 123 K,the guest molecules in the noncentral tunnels are ordered (although with conformational disorder of the bromine end-groups),whereas the guest molecules in the central tunnel are disordered. At 293 K,there is substantial disorder of the guest molecules in both the central and non central tunnels. The structural properties of 1,8-dibromooctane/TOT contrast with those of other #alpha#,#omega#-dihalogenoalkane/TOT inclusion compounds.