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Product analyses and nanosecond time-resolved spectroscopy on laser flash photolysis are analyzed for the photoinduced electron-transfer reaction of 3,4-di([alpha]-styryl)furan. A new method is provided for the generation of aryl-substituted tetramethyleneethane (TME)-type intermediates.

The results of an investigation of the thermoluminescence and electroluminescence of arylated methylenecyclopropanes 1 are described. The mechanistic features of this reaction system have the potential of overcoming significant problems associated with organic light emitting diodes.

Results obtained for the three types of electro transfer (ET) fluorescence quenching and back ET with three types of geminate radical pairs were compared with one another to characterized photoinduced ET in polar solvents such as acetonitrile and methanol. In acetonitrile, N-methylacridinium ion was used as a monocationic fluorescer and aromatic compounds as neutral quenchers. In methanol, aromatic compounds were used as neutral fluorescers and methyl and benzyl viologens as dicationic quenchers. Results showed that the molecular charge has no effect on the rates of fluorescence quenching and back ET, but it affected the rate of geminate radical separation into free radicals.

A cation-radical cyclization-diradical cleavage mechanism is believed responsible for a degenerate Cope rearrangement undergone by 2,5-diaryl-3,3,4,4-tetradeuterio-1,5-hexadiene to afford a photostationary mixture of d(sub 4)-1 amd its 1,1,6,6-tetradeuterio derivative. The reaction involves 1,4-diaryl-2,2,3,3-tetradeuteriocyclohexane-1,4-diyl cation radical, while the nonphotoinduced electron transfer reaction of d(sub 4)-1 with cerium(IV) ammonium nitrate also forms d(sub 4)-2*+ but does not lead to degenerate Cope arrangement.

The synthesis and characterization of fluorophore-amino acid-cyclodextrin (CD) triads as molecular sensors were carried out. The fluorescent CDs, which displayed variable fluorescence and absorption intensities upon addition of a guest molecule, were N-dansyl-L-leucine-modified and N-dansyl-D-leucine-modified beta-CD, and N-dansyl-L-leucine-modified and N-dansyl-D-leucine-modified gamma-CD.

A ternary inclusion complex of beta-cyclodextrin (beta-CD) with alcohol and azulene is studied by induced circular dichroism (ICD) and 1H NMR techniques. The complex consists of two beta-CD's, two alcohols and one azulene. The fluorescence spectra of azulene aqueous solution with varying concentration of beta-CD and the ICD spectra with beta-CD and with both beta-CD and 1-propanol are presented.

Spectroscopic and calorimetric evidence together with results of product analysis, which support the participation of two different types of intermediates in the PET methylenecyclopropane rearrangements is presented. The conclusion states that the PET degenerate rearrangement of d2-1 proceeds in a CRCL-DRCY mechanism involving the large twisted TMM action radical and diradical intermediates d2-6+ and d2- 6 respectively.

A study is conducted to examine the photoinduced electron-transfer reactions of 2,2-bis(p-methoxyphenyl)-3,3-dimethyl-4-methylnecy-clobutanone and 2,2-bis(p-methoxyphenyl)-4-isopropylidenecyclobutanone. This study produced a new substance in the field of non-Kekule chemistry, which would affect related fields of reactive intermediate, electron-transfer chemistry and organic photochemistry.

Mechanistic studies were conducted to observe two different types of trimethylenemethane (TMM) intermediates using nanosecond laser flash photolysis, electron paramagnetic resonance spectroscopy and photoacoustic calorimetry. Results showed the participation of two types of TMM intermediates in the degenerate methylenecyclopropane rearrangement of 4,4-dideuterio-2,2-bis(4-methoxyphenyl)-1-methylenecyclopropane. A proposed rearrangement sequence including a back electron transfer process provide the first observation of the interconversion of intermediates.