Proton transfer coupled

Solvation Dynamics in the Proton Transfer Coupled Charge Transfer Reaction. 248... 

Chou PT, Huang CH, Pu SC et al (2004) Tuning excited-state charge/proton transfer coupled reaction via the dipolar functionality. J Phys Chem A 108 6452-6454... 

Mileni, M. Haas, A. H. Mantele, W. Simon, J. Lancaster, C. R. D. Probing Heme Propionate Involvement in Transmembrane Proton Transfer Coupled to Electron Transfer in Dihemic QuinokEumarate Reductase by C-Labeling and FTIR Difference Spectroscopy. Biochemistry 2003, 44, 16718-16728. 

Proton Transfer Coupled to Electron or Hole Transfer... 

It was noted above that the photolysis of indole and aldehydes in the solid state leads to diindolymethanes by a mechanism postulated to involve an oxetane intermediate (Scheme 14). The reaction also proceeds when aromatic aldehydes and indole or 2-methylindole are irradiated with UV light in acetonitrile solution (Scheme 28) [61]. Under these circumstances, it has been proposed that light-induced electron transfer from the indole to the aldehyde yields a ketyl radical anion and the indole radical cation. Proton transfers, coupling, and elimination of water can then yield an electrophilic alkylidene indolenine 65 which can react with indole thermally to give the observed product. 

We can detect whether electron transfer is coupled to the proton transfer reaction by measuring the redox potential over as wide a pH range as enzyme stability allows. If E° is independent of pH, this indicates that there is no proton transfer coupled to the electron transfer reaction, or that the simultaneous ionization of the oxidized and reduced forms offset one another (see below). However, if proton transfer is coupled to electron transfer for a particular redox state, the electron transfer will be dependent on pH. For enzymes, proton transfer usually accompanies electron transfer in order to maintain charge neutrality at the active site. This is illustrated in the simple case of oxidized free flavin, abbreviated (Flox). In order to understand how pA a... 

Among oxygen acids, proton-transfers coupled with structural change elsewhere occur particularly in the addition reactions of the carbonyl... 

Fig. 5.21. Delocalized and localized models of proton transfer coupled with ATP synthesis in chloroplasts. (Reproduced, with permission, from the Annual Review of Plant Physiology, Volume 38, 1987, by Annual Reviews Inc.)...

FIGURE 68.24 Proposed potential energy surface diagram for the proton-transfer-coupled intramolecular charge transfer of DMAS/fi CD system. 

Kim, Y, Yoon, M., and Kim, D., Excited-state intramolecular proton transfer coupled-charge transfer of N,N-dimethylaminosahcylic acid in aqueous P-cyclodextrin solutions, /. Photochem. 

Fig. 3. Working principle of sensor proton-transfer coupling reverse PET, on-off.

Typical amphoteric liquids include phosphoric acid and diverse heterocycles such as imidazole, pyrazole, benzimidazole, and triazole. In the liquid state, they all show relatively high proton conductivities with significant contributions from structure diffusion, that is, the motion of protonic defects (excess or deficient protons) by intermolecular proton transfer, coupled to hydrogen bond breaking and forming processes. A promising approach to eliminate the liquid electrolyte is to attach the protic groups of the liquid electrolyte to... 

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