Synthesis of N,N'-bis(9-phenylxanthen-9-yl)ethylenediamine and an investigation of its host-guest inclusion potential

The novel amine, N,N'-bis(9-phenylxanthen-9- yl)ethylenediamine 1, was synt hesized by treating 9-phenylxanthen-9-ylium perchlorate with ethylenediamin e. Its host potential was assessed by allowing it to crystallise from a ran ge of organic solvents (single and binary mixtures), of which several were found to be included. The stoichiometries of these host-guest complexes wer e determined through H-1-NMR analysis and their stabilities assessed throug h thermal analysis. Single crystal X-ray crystallography was used to elucid ate the crystal structure of the 1:1 1 . THF inclusion complex. It was foun d that only one of the two amine moieties of the host functions as a donor, forming a nearly linear hydrogen bond to the oxygen atom of the guest mole cule. Each THF molecule is effectively surrounded by host molecules so that the THF molecules are found to occupy discrete "cavities" within the host lattice. The activation energy associated with desolvation of the 1 . THF c omplex was determined through thermal analysis and was found to decrease as desolvation progressed.