Rearrangements in Model Peptide-Type Radicalsvia Intramolecular Hydrogen-Atom Transfer

Excited-state intramolecular hydrogen atom transfer of curcumin in surfactant micelles.

Femtosecond fluorescence upconversion experiments were performed on the naturally occurring medicinal pigment, curcumin, in anionic, cationic, and neutral micelles. In our studies, the micelles are composed of sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and triton X-100 (TX-100). We demonstrate that the excited-state kinetics of curcumin in micelles have a fast (3-8...

The intramolecular hydrogen atom transfer in the photodissociation of o-chlorotoluene

Based on ab initio calculated results, a new mechanism is proposed that intramolecular hydrogen atom transfer may occur Ž . during the photodissociation of o-chlorotoluene at 266 nm. This mechanism is different from the general suggestion, i.e. 1 Ž . Ž . Ž . Ž . o-chlorotoluene S TMo-chlorotoluene T TMClqo-tolylTMbenzylqCl. Our suggestion is 2 o-chlorotoluene S TMo1 1 1 Ž . Ž . Ž . chlorotoluen...

Solvent Dependence on the Intramolecular Excited-State Proton or Hydrogen Atom Transfer in Hypocrellin

Hypocrellin and its analog, hypericin (Figure 1), are naturally occurring quinones that have been used for centuries as folk medicines in the orient and the occident and that have attracted much interest because of their light-induced toxicity toward the human immunodeficiency virus (HIV).1The structural similarities of hypocrellin and hypericin would seem to suggest that hypocrellin exhibits e...

Conventional and Unconventional Intramolecular Hydrogen Bonding in some Beta-diketones

This study presents our view of unconventional and conventional intramolecular hydrogen bonds (HBs) for some beta-diketones theoretically and experimentally. According to our results, the groups such as Phenyl and t-But in beta positions increase and CF3 group decrease IHB strength, respectively. For better understanding of the substitution effects, the compounds with similar and different subs...

Controlling intramolecular hydrogen transfer by single atoms and molecules