Formation of solute excited states and radicals during pulse radiolysis of naphthalene in ethereal solutions

Abstract

Yields of solute radicals and triplet and singlet excited states differ markedly for solutions of naphthalene in two ethers, 1,2-dirnethoxyethane (DME) and tetrahydrofuran (THF), which have almost the same dielectric constant (7.2 and 7-4 respectively at 25°C). The concentration dependences reveal that in both solvents the production of radicals and excited states are not inter-related in a simple manner ; production of singlet and triplet states do, however, seem to be related.Considerable attention has been focused on the yield of ionic intermediates in the radiolysis of liquids. The production of the spectrum of eG in pulse radiolysis of water is convincing evidence for an extensive degree of ionization. Lower yields of e&.. are obtained on pulse radiolysis of alcohols and other moderately polar liquids and addition to methanol of potent electron scavenger^,^ e.g., biphenyl

Poly(3-decylthiophene) Radical Anions and Cations in Solution: Single and Multiple Polarons and Their Delocalization Lengths in Conjugated Polymers

“…Four species can contribute to these steps: solvated electrons, singlet and triplet excited states of P3DT, and P3DT radical anions (P3DT –• ). Small yields of excited states are known to be formed in the pulse radiolysis of THF . In the present experiments, emission was observed with a spectrum and lifetime of ∼0.6 ns similar to that reported for poly(3-octylthiophene) in THF .…”

“…Small yields of excited states are known to be formed in the pulse radiolysis of THF. 49 In the present experiments, emission was observed with a spectrum and lifetime of ∼0.6 ns similar to that reported for poly(3-octylthiophene) in THF. 50 For times longer than 2 ns, there are negligible contributions from singlets, which convert to triplets with a high quantum yield for intersystem crossing (ϕ = 0.958).…”

Sub-picosecond Production of Solute Radical Cations in Tetrahydrofuran after Radiolysis

“…In work examining ultrafast electron capture by conjugated polymers in THF, we noted possible production of polymer radical cations faster than 15 ps, but were unable to identify the source . Finally there have been a number of reports of delayed emission and triplets in ethers including THF − as well as in methanol and ethanol. , These are puzzling results as one would normally expect such chemistry only follows recombination of radical anions and radical cations, which should not exist in rapidly hole-fragmenting media.…”