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Pregled bibliografske jedinice broj: 532388

Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution


Jakobušić Brala, Cvijeta; Karković, Ana; Sajenko, Ivana; Pilepić, Viktor; Uršić, Stanko
Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution // Zeitschrift für physikalische Chemie, 226 (2012), 1; 29-46 doi:10.1524/zpch.2011.0150 (međunarodna recenzija, članak, znanstveni)


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Naslov
Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution

Autori
Jakobušić Brala, Cvijeta ; Karković, Ana ; Sajenko, Ivana ; Pilepić, Viktor ; Uršić, Stanko

Izvornik
Zeitschrift für physikalische Chemie (0942-9352) 226 (2012), 1; 29-46

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
proton-coupled electron transfer; kinetic isotope effect; hydrogen tunnelling; dynamics; quaternary ammonium ion; ascorbate

Sažetak
The presence of quaternary ammonium ions unexpectedly leads to a sizable increase of the kinetic isotope effects in the coupled electron-proton transfer (PCET) reaction of an ascorbate monoanion with the hexacyanoferrate(III) ions in water and this, in “neat” water over-the-barrier coupled electron-proton transfer interaction, entered into tunnelling regime in the presence of the quaternary ions. The kinetic isotope effect between ascorbate monoanion and its 2-OD derivative in the investigated reaction with hexacyanoferrate(III) increased from kH/kD = 4.40(0.08) in the reaction in water (in the presence of 8×10-3 M NaCl) without the added quaternary ions, to kH/kD = 10.08(0.07) in the presence of 1.0 M tetraethylammonium ion, to kH/kD = 8.01(0.19) in the presence of 1.0 M of benzyltrimethylammonium ion and to kH/kD = 7.25(0.02) in the presence of only 0.1 M of tetraethylammonium ion. In contrast, kH/kD = 4.06(0.15) has been observed in presence of 0.1 M NaCl. The isotopic ratio of Arrhenius pre-factors AH/AD = 0.16(0.01) has been obtained in the presence of only 0.1 M of tetraethylammonium ions and AH/AD = 0.10 (0.02) in the presence of 0.5 M of the ions. The corresponding observed value is AH/AD = 0.23 (0.02) in the presence of 0.5 M of benzyltrimethylammonium ions and AH/AD = 0.35 (0.06) in the presence of 0.5 M tetramethylammonium ions. The differences in the enthalpies of activation H‡ between D2O and H2O all are well beyond the semiclassical value of 5.1 kJ/mol for the difference between zero-point energies EoDEoH for dissociation of an OH bond. The observed tunnelling phenomena point to a role of dynamics of the transition configuration of the PCET process, coupled with dynamics of hydrogen-bonded structures related to the solvent shell of the reactive configuration and its environment including the nearby quaternary ammonium ions.

Izvorni jezik
Engleski

Znanstvena područja
Kemija



POVEZANOST RADA


Projekti:
006-0063082-0354 - Fizikalno kemijske interakcije biomedicinski važnih prirodnih antioksidansa (Pilepić, Viktor, MZOS ) ( POIROT)

Ustanove:
Farmaceutsko-biokemijski fakultet, Zagreb

Poveznice na cjeloviti tekst rada:

doi www.degruyter.com

Citiraj ovu publikaciju:

Jakobušić Brala, Cvijeta; Karković, Ana; Sajenko, Ivana; Pilepić, Viktor; Uršić, Stanko
Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution // Zeitschrift für physikalische Chemie, 226 (2012), 1; 29-46 doi:10.1524/zpch.2011.0150 (međunarodna recenzija, članak, znanstveni)
Jakobušić Brala, C., Karković, A., Sajenko, I., Pilepić, V. & Uršić, S. (2012) Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution. Zeitschrift für physikalische Chemie, 226 (1), 29-46 doi:10.1524/zpch.2011.0150.
@article{article, author = {Jakobu\v{s}i\'{c} Brala, Cvijeta and Karkovi\'{c}, Ana and Sajenko, Ivana and Pilepi\'{c}, Viktor and Ur\v{s}i\'{c}, Stanko}, year = {2012}, pages = {29-46}, DOI = {10.1524/zpch.2011.0150}, keywords = {proton-coupled electron transfer, kinetic isotope effect, hydrogen tunnelling, dynamics, quaternary ammonium ion, ascorbate}, journal = {Zeitschrift f\"{u}r physikalische Chemie}, doi = {10.1524/zpch.2011.0150}, volume = {226}, number = {1}, issn = {0942-9352}, title = {Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution}, keyword = {proton-coupled electron transfer, kinetic isotope effect, hydrogen tunnelling, dynamics, quaternary ammonium ion, ascorbate} }
@article{article, author = {Jakobu\v{s}i\'{c} Brala, Cvijeta and Karkovi\'{c}, Ana and Sajenko, Ivana and Pilepi\'{c}, Viktor and Ur\v{s}i\'{c}, Stanko}, year = {2012}, pages = {29-46}, DOI = {10.1524/zpch.2011.0150}, keywords = {proton-coupled electron transfer, kinetic isotope effect, hydrogen tunnelling, dynamics, quaternary ammonium ion, ascorbate}, journal = {Zeitschrift f\"{u}r physikalische Chemie}, doi = {10.1524/zpch.2011.0150}, volume = {226}, number = {1}, issn = {0942-9352}, title = {Sizeable Increase of Kinetic Isotope Effects and Tunnelling in Coupled Electron–Proton Transfers in Presence of the Quaternary Ions. PCET Processes and Hydrogen Tunnelling as a “Probe” for Structuring and Dynamical Phenomena in Water Solution}, keyword = {proton-coupled electron transfer, kinetic isotope effect, hydrogen tunnelling, dynamics, quaternary ammonium ion, ascorbate} }

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus


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