Studies on novel macrocyclic sulphur compounds

This thesis describes the synthesis and properties of 2,2'-­bridged biphenyls in which sulphur or oxygen functions are incorporated into the bridging unit. Seven-, eight-, nine-, ten­- and eleven-membered ring systems were prepared by nucleophilic substitution of alkylene a, w -dihalides, xylylene dihalides or dialkyl ether ?, w-dihalides by alkali metal dimercaptides or 2,2'- biphenoxide. A homologous series of cyclic disulphones has been prepared by oxidation of the parent disulphide systems with hydrogen peroxide. The nuclear magnetic resonance spectra of appropriate compounds are discussed and related to the optical stability of these disymmetric systems. Partial optical resolution of the dithia-heterocycles and the relation between their stereochemistry and optical stability is described, The ultraviolet spectra of the bridged and unbridged biphenyls is discussed and related to the conformation of the biphenyl rings. The thermal degradation of some "acyclic" disulphonium salts with the formation of dibenzothiophen is discussed. The preparation of fourteen-, sixteen-, eighteen- and twenty-four­membered tetrathia-heterocyclic systems containing the ?- xylylene bridge is described. A brief description of the divalent palladium and platinum complexes of the "acyclic" disulphides is given. Finally, the mass spectra of many of the compounds are discussed