Clathrate design for dioxane inclusion involving singly bridged triarylmethanol hosts. Synthesis, X-ray crystal structures and thermal stabilities of five inclusion compounds

Desorption kinetics of a xanthenol–dioxane clathrate

“…The host naphthalene moiety and the xanthene ring are nearly orthogonal, the dihedral angle between their least-squares planes being 88.21 (2) . This is comparable with the conformation found in similar structures, such as bis(9-phenyl-9hydroxy)xanthene tris(dioxane) clathrate (Cso È regh et al, 1993). In other structures, such as 9-(cyclohepta-2,4,6-trien-1yl)xanthen-9-ol (Badejo et al, 1991), the dihedral angle is substantially different, at 21.9 (2) .…”

“…We used the program SECTION (Barbour,1999a) to map the cavities and found that the approximate size of these cages is 7.6 Â 6.5 Â 7.4 A Ê . This compares favourably with other structures, such as the 9-[4-(tert-butyl)phenyl]¯uoren-9-ol±dioxane clathrate (Cso È regh et al, 1993), where the cages have approximate dimensions 5.7 Â 7.1 Â 9.7 A Ê .…”

“…Dioxane is an interesting guest molecule, since it has two O atoms which are capable of being hydrogen-bond acceptors. A series of similar hosts have been observed to include dioxane, with host±guest stoichiometries varying from 2:1 to 2:3 (Cso È regh et al, 1993), with the guests situated in channels or cages. In this study, each host molecule is hydrogen bonded via organic compounds o668 # 2004 International Union of Crystallography DOI: 10.1107/S0108270104017792…”

A history of the Chemistry Department, University of Cape Town

“…Recently, host-guest aspects of intermolecular reactions have been studied on a wide scale. Under Nassimbeni, many organic inclusion compounds that enclathrate volatile guest molecules have been investigated Bourne et al, 1991;Csoregh et al, 1993;Caira et al, 1994aCaira et al, ,b, 1996aBarbour et al, 1995;Nassimbeni, 1998), this study being amplified by a correlation of the structures found with other physical properties such as thermodynamic stability and associated decomposition kinetics. Optical resolution of racemates has also been achieved (Toda et al, 1988).…”

Competitive interactions in crystalline 9-pyridyl-9-fluorenols: crossover from O–H⋯O to O–H⋯N hydrogen bonding to construct intra- and intermolecular, helical and linear contact modes

“…13 However, in many cases, due to the bulkiness of the basic skeletons, interactions between the molecules as host and solvents as guest components are necessary for stabilization of the crystal lattice forming solvates. [14][15][16][17][18] Replacement of the aryl group, e.g. the phenyl ring in 1 for a pyridyl moiety (2-4, Fig.…”