The Synthesis of Novel Enclathration Compounds : Bis(9-amino-9-aryl-9H-thioxanthenes) and Investigations of their Host-Guest Inclusion Potential

Abstract

Four novel bis(9-amino-9-aryl-9H-thioxanthenes) were synthesized and their inclusion potential assessed by allowing them to crystallize slowly from organic solvents (single and binary mixtures). Only two of the compounds studied displayed inclusion ability and enclathrated several of the solvents studied. The stoichiometries of the resultant inclusion complexes were determined by 1H-NMRstudies, and the favoured host:guest ratios were found to be predominantly 1 : 1, with ratios 2 : 1, 4 : 3 and 3 : 2 occurring less frequently. The stability of the clathrate complexes has been investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Competition experiments were carried out with the compounds that successfully hosted solvent molecules in order to determine their relative affinity for these solvents. One of the hosts was also exposed to two vaporous guests in two separate experiments to assess its ability for entrapping molecules from the vapour phase.


South African Journal of Chemistry Vol.55 2002: 144-148