Crystal engineering of porosity
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006.
Inclusion and porosity properties of the following supramolecular solid-state hosts were investigated: • 2,7-dimethylocta-3,5-diyne-2,7-diol • 2-methyl-6-phenylhexa-3,5-diyn-2-ol • Dianin’s compound • p-tert-butyl-calixarene • 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxy-2,8,14,20- tetrathiacalixarene • Two discrete coordination metallocycles, [Ag2IMID2](BF4)2 and [Cu2(BITMB)2(Cl)4] All of these compounds form well-defined crystalline host structures. Inclusion phenomena involving encapsulation of liquids were studied using single-crystal x-ray diffraction methods. Several guest-free host structures (α phases) were structurally elucidated and their gas sorption properties were investigated. Studies of the sorption properties of seemingly nonporous materials were carried out to provide insight into this rare phenomenon. Water and iodine sorption by a polymorph of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxy-2,8,14,20- tetrathiacalixarene shows that the conventional perception of sorption through the solid-state requires reassessment. Gas sorption studies were carried out using apparatus devised and presented here. These include sorption apparatus and a device to determine single-crystal structures under controlled gas atmospheres.