Crystal Structure, Thermal Decomposition Behavior, and Order−Disorder Transition of the Guest Component of Concomitant Pseudodimorphic Clathrates between 2,2‘-Bis(9-hydroxy-9-fluorenyl)biphenyl Host and Chloroform Guest

Abstract

Two clathrates between the 2,2‘-bis(9-hydroxy-9-fluorenyl)biphenyl host and chloroform guest, having 1:2 (α-phase) and 1:1 (β-phase) stoichiometries, have been obtained in the same vial by fast evaporation of a supersaturated solution in chloroform. The structures of the pseudodimorphs were determined by single-crystal X-ray diffraction. Their thermal properties were studied by using combined thermogravimetry-differential scanning calorimetry (TG-DSC), variable temperature X-ray powder diffraction in the temperature interval 20−250 °C, and DSC in the low-temperature interval from −140 to 20 °C. The thermal decomposition behavior of the α- and β-phase pseudodimorphs, a difference in the desolvation onset temperatures, as well as an occurrence of endothermic peaks in the low-temperature DSC curves (order−disorder transition of the guest component) have been explained on the basis of the structural data.