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

• Published in: Crystal growth & design 2003-07, Vol.3 (4), p.541-546
• Main Authors: Sumarna, Omay, Seidel, Jürgen, Weber, Edwin, Seichter, Wilhelm, Ibragimov, Bakhtiyar T, Beketov, Kayrat M
• Format: Article
• Language: English
• Subjects: Aliphatic, non-condensed and condensed benzenic, and alicyclic compounds; Condensed matter: structure, mechanical and thermal properties; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Exact sciences and technology; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg034013a

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.