A comparative study of crystal structures and inclusion properties of fluorinated triazines

Three perfluorinated host compounds of the triazine type, namely 2,4,6-tris(pentafluorophenoxy)-1,3,5-triazine (<b>1</b>), 2,4,6-tris(pentafluorothiophenoxy)-1,3,5-triazine (<b>2</b>) and 2,4,6-tris(pentafluorophenamin)-1,3,5-triazine (<b>3</b>), were synthesized differing only in the linking heteroatom (O, S and NH) between the triazine core and the pentafluorophenyl groups. The crystal structures involving compounds <b>1</b>, <b>2</b> and their inclusion compounds are dominated by a variety of fluorine interactions (phenyl-perfluorophenyl, C–HF, FF, C–FπF). However, in the structure of <b>3</b>, possessing additional hydrogen atoms of the linkage NH-groups, the formation of hydrogen bonds is favoured, whereas fluorine contacts are less apparent. Investigations by powder X-ray diffraction and thermogravimetric analysis revealed substantial differences in the host–guest interactions of the inclusion compounds.