| This thesis describes the chemistry of highly chlorinated or brominated cyclopentadiene dimers and cages. Some structures previously assigned were either corrected or confirmed unambiguously by single-crystal X-ray analyses.; BromoMirex reacts with sodium methoxide in THF to give a dimethoxy compound. Its structure was reassigned to 2,8-dimethoxydecabromopentacyclo-[5.3.0.0 2,6.03,9.04.8]decane. The reactions of sodium methoxide with highly chlorinated homocubane/bishomocubane compounds were also examined. The mechanism of this remarkable displacement was investigated.; Polychlorohomocubanes were found to be inert to conventional SN 2 and SN1 reactions, but they readily reacts with lithium triethylborohydride to give hydrogen(s) substituted cages. The mechanism of this reaction is explained as a SET process involving a cage radical intermediate.; The structure of the major product of photochlorination of bis-(pentachlorocyclopen tadienyl) was unambiguously reassigned to dodecachloro-cis,anti,cis -tricyclo[5.3.0.02,6]deca-4,9-diene. Aluminum chloride-catalyzed chlorination of bis-(pentachlorocyclopentadienyl) gave endo and exo Diels-Alder dimer of hexachlorocyclopentadiene. The structures of these two compounds were confirmed to be correct. The mechanism of Prins dimerization was investigated and the aluminum chloride-induced formation of pentachlorocyclopentadiene cation was concluded to be the rate determining step. In addition, the stereochemistry of Diels-Alder dimer of pentachlorocyclopentadiene was determined. This dimer reacts with aluminum chloride to give rearrangement products. The mechanism of this rearrangement is explained as an elimination/addition process.; The structures of various perhalodiones available by isomerization of the Diels-Alder dimer of tetrachloro- and tetrabromocyclopentadienone were determined unambiguously. The structure of the photoisomerization product of Octachloro-cis,anti,cis-tricyclo[5.3.0.02,6]deca-4,9-diene-3,8-dione was reassigned to anti9,10-octachlorotricyclo[4.2.1.1 2,5]deca-3,7-diene-9,10-dione. Finally, octachloro-3a,4,7,7a-tetrahydro-1 H-4,7-methano-indene-1,8-diol was prepared and its reactivity toward Lewis acid was examined. |
