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The use of elemental iodine as an in situ oxidant allows the metal vapor synthesis of bis($\eta\sp 6$-arene)manganese cationic sandwich complexes from alkyl substituted arenes. These stable 18 electron species are isolated as hexafluorophosphate salts. $\sp 1$H NMR, $\sp{13}$C NMR, and FABMS spectra were secured for each compound.

Part I. A series of bichromophoric molecules linked by an ester bridge is synthesized, and their photochemical and intramolecular energy transfer properties are examined. If benzophenone and naphthalene are held approximately 10 A apart by this ester bridge rather than by an alkyl chain, intramolecular energy transfer is only 93% to 97% complete in a frozen glass, rather than 100% complete. This value shows the previous critical radius of 13 A from the sphere of quenching model to be too long. The reason and rationalization for this loss of energy transfer efficiency is explored. Several irradiation experiments are also conducted, studying both intramolecular and intermolecular energy transfer along competing pathways. Part II. The stereochemistry of 4-benzoyl-2,3-diazabicyclo(2.2.2) oct-2-ene is studied using various two-dimensional NMR techniques.

A two-step synthesis of spiro(2.4) hepta-1,4,6-triene 1 is described. The starting material 2 was synthesized by irradiation of diazocyclopentadiene in the presence of (2-bromovinyl)trimethylsilane. The predominant formation of the trans isomer probably reflects the isomeric composition of the starting alkene (cis:trans ratio $\approx$ 10:90). Elimination of 2 using CsF in dimethyl sulfoxide yielded 1.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE MAI) Spiro (2.4) hepta-1,4,6-triene is remarkably stable. $\rm\sp1H$ and $\rm\sp{13}C$ NMR data could be obtained at room temperature. The infrared spectrum exhibits a moderately strong absorption at 1713 $\rm cm\sp{-1}$ characteristic of cyclopropenes. The ultraviolet spectrum of spiro (2.4) hepta-1,4,6-triene recorded in methanol has $\lambda\sb{\rm max}$ = 254 nm, very close to that reported (257 nm) for 3. This observation is in conflict with theoretical predictions which claim that 1 will experience a small hypsochromic shift resulting from spiroconjugation.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE MAI)