Glenn E. Lawson

Photoinduced inter- and intra-molecular electron transfer reactions of [60]fullerene and a tertiary amine. Formation of the cycloadduct N-ethyl-trans-2′,5′-dimethylpyrrolidino[3′,4′:1,2][60]fullerene

The photoreduction of [60]fullerene by triethylamine results in the formation of a cycloadduct N-ethyl-trans-2′, 5′-dimethylpyrrolidino[3′,4′: 1,2][60]fullerene, which is probably due to sequential intermolecular and intramolecular processes and argues strongly for the presence of ion pairs as intermediates in a room temperature toluene solution.

Electron donor-acceptor interactions of fullerenes C60 and C70 with triethylamine

Abstract The absorption spectra of C 60 and C 70 undergo dramatic changes from a neat toluene solution to a neat triethylamine (TEA) solution. It is shown that the observed spectral changes are due to the bleaching of the C 60 and C 70 monomer absorptions and the absorption contributions of fullerene-TEA reaction products, not due to C 60 (C 70 )-TEA complexes. Dependencies of the chemical reactions on TEA concentration and time are examined. The electron transfer quenching of C 60 and C 70 monomer fluorescence intensities at low TEA concentrations is discussed.

Fullerene-based macromolecules from photochemical reactions of [60]fullerene and triethylamine

Abstract [60]fullerene-triethylamine macromolecules are obtained from photoinduced electron transfer-proton transfer reactions. The material is characterized by photon correlation spectroscopy of quasi-elastic light scattering, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, NMR and FT-IR techniques. The electronic absorption and emission properties of the material are studied. Because the macromolecules likely contain intramolecular redox pairs, the possibility of intramolecular exciplexes is examined and discussed.

Effects of photochemical reactions of pyrene in alcohol and aqueous solvent systems on spectroscopic analyses

Although pyrene is a popular fluorescent molecular probe in analytical and bioanalytical chemistry, its photostability is hardly understood. This paper reports a surprising finding that pyrene undergoes significant photochemical reactions in alcohol and aqueous solvents under the condition of exposing a sample solution to excitation irradiation in an emission spectrometer for a short period of time. The reactions yield at least two photoproducts, whose fluorescence spectra overlap severely with that of pyrene. Implications of pyrene photochemical reactions in alcohol and aqueous solvent systems to existing and future applications of pyrene as a fluorescent molecular probe are discussed.

Photochemical Preparation of Highly Water-Soluble Pendant [60]Fullerene-Aminopolymers

Abstract— In order to introduce fullerene cages into an aqueous environment, pendant [60]fullerene‐poly(propionylethyle‐neimine‐co‐ethyleneimine) was prepared photochemical‐ly. The pendant polymer is highly water soluble, with equivalent aqueous solubilities of the polymer‐bound [60]fullerene much higher than the solubility of [60]ful‐lerene in toluene. The photochemical reaction between [60]fullerene and secondary amine moieties in the ami‐nopolymers likely follows a photoinduced electron transfer‐proton transfer mechanism. The pendant polymer structures, which are represented by dehydrogenated di‐and tetra‐aminofullerene linkages, were characterized by use of proton and 13C NMR, Fourier transform‐infrared spectroscopy, gel‐permeation chromatography and optical spectroscopic methods.

Polymeric fullerene hydrides. Birch reduction of [60] fullerene polymers from solution-based photopolymerization and free radical polymerization reactions

Fullerene polymers represent a new class of carbon materials for potential hydrogen storage applications. Poly[60]fullerene polymers were obtained by covalently linking [60]fullerene molecules in photochemical reactions. [60]Fullerene polymers were also prepared in free radical reactions of [60]fullerene with radical initiator benzoyl peroxide. The polymeric [60]fullerene materials were hydrogenated under Birch reduction conditions. The hydrides, which contain ≈3.5% (wt/wt) of hydrogen, were characterized by use of gel permeation chromatography, NMR, FT-IR, and elemental analysis. The results are compared with those of monomeric [60]fullerene hydrides.