Structures and thermal stability of selected organic inclusion compounds

• Main Author: Janjic, Nikolina
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2015
• Subjects: Chemistry
• Online Access: http://hdl.handle.net/11427/14968

Includes bibliographical references. === The crystal structures of 1,1 ,6,6-Tetraphenyl-hexa-2,4-diyne-1 ,6-diol and 5-(3,5- Dicarboxyphenylethynyl)-isophthalic acid hosts with various guests have been elucidated. Depending on their structural properties and the way in which the host components pack, the guests may become trapped in spaces or voids, stacked in channels or sandwiched between layers of hosts. The crystal structures are stabilised by hydrogen bonding networks created by host-guest intermolecular interactions. The host hydroxy moieties adopt a trans conformation in 1,1 ,6,6-Tetraphenyl-hexa-2,4-diyne-1 ,6- diol host-guest inclusion componds. Host-guest hydrogen bonding in 5-(3,5- Dicarboxyphenylethynyl)-isophthalic acid salts occurs via the carboxylate group of the host anion. Hydrogen bond formation was the directing force determining the form of a host-guest array. The crystal structures of four inclusion compounds with 1,1 ,6,6-Tetraphenyl-hexa-2,4- diyne-1 ,6-diol host and six hydrated salt structures with 5-(3,5-Dicarboxyphenylethynyl)isophthalic acid host were solved using the single crystal X-ray diffraction technique. In addition the thermal stability and the structural properties of all compounds were investigated by thermal analysis techniques, including differential scanning calorimetry, thermogravimetry and hot-stage microscopy.