Yan, Joseph Shue-Hen2024-08-152024-08-1519781978https://hdl.handle.net/1828/20226In this work we have synthesised a symmetrical benzanne­lated dimethyldihydropyrene and s.h0vm that it is aromatic both in terms of magnetic effects (diatropic and large 'Q' value) and classical reaction chemistry (in that it U1.1de rgce3 electrophilic substitution reactions). Synthetic procedures have been developed which allow a base-induced sulphinic acid elimination as an alter­native to the better-known Hofmann type sulphonium salt elimina­tion in the last step of the sequence to produce cyclophane-dienes. Also a method has been found whereby alkyl substituents may be introduced onto the bridge position of the phane-diene. The synthesis of the first terphenylophane is also described . The phototautomerisation of the benzodimethyldihydropyrene and its derivatives has been studied, and it is found that the activation barriers between the phane-diene=dihydropyrene tau­tomers are somewhat higher (i.e. process is slower) than for the parent system. The barriers to rotation in several substituted terphenyls have also been determined.122 pagesAvailable to the World Wide WebThesis