Cascade proton relays facilitate electron transfer across hydrogen‐bonding network

2022 ◽  
Author(s):  
Heechan Kim ◽  
Dongwhan Lee
Keyword(s):  
Electron Transfer ◽  
Hydrogen Bonding ◽  
Hydrogen Bonding Network

The hydrogen-bonding network in deacetylcephalothin

2005 ◽  
Vol 61 (11) ◽  
pp. o625-o627
Author(s):  
Janusz Zachara ◽  
Izabela D. Madura ◽  
Andrzej Zimniak ◽  
Irena Oszczapowicz ◽  
Iwona Chrobak
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonding Network

Remarkable low symmetry hydrogen bonding network in the structure of ReCl2(NCMe)(NO)(PMe3)2

2000 ◽  
Vol 306 (2) ◽  
pp. 153-159 ◽  
Author(s):  
Heiko Jacobsen ◽  
Helmut W Schmalle ◽  
Andreas Messmer ◽  
Heinz Berke
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonding Network ◽  
Low Symmetry

scholarly journals Flavones’ and Flavonols’ Antiradical Structure–Activity Relationship—A Quantum Chemical Study

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 461 ◽  
Author(s):  
Maciej Spiegel ◽  
Tadeusz Andruniów ◽  
Zbigniew Sroka
Keyword(s):  
Electron Transfer ◽  
Hydrogen Bonding ◽  
Density Functional ◽  
Hydrogen Abstraction ◽  
Quantum Chemical Study ◽  
Hydrogen Atom Transfer ◽  
Hydroxyl Group ◽  
Water Solvent ◽  
Intramolecular Hydrogen ◽  
Catechol Moiety

Flavonoids are known for their antiradical capacity, and this ability is strongly structure-dependent. In this research, the activity of flavones and flavonols in a water solvent was studied with the density functional theory methods. These included examination of flavonoids’ molecular and radical structures with natural bonding orbitals analysis, spin density analysis and frontier molecular orbitals theory. Calculations of determinants were performed: specific, for the three possible mechanisms of action—hydrogen atom transfer (HAT), electron transfer–proton transfer (ETPT) and sequential proton loss electron transfer (SPLET); and the unspecific—reorganization enthalpy (RE) and hydrogen abstraction enthalpy (HAE). Intramolecular hydrogen bonding, catechol moiety activity and the probability of electron density swap between rings were all established. Hydrogen bonding seems to be much more important than the conjugation effect, because some structures tends to form more intramolecular hydrogen bonds instead of being completely planar. The very first hydrogen abstraction mechanism in a water solvent is SPLET, and the most privileged abstraction site, indicated by HAE, can be associated with the C3 hydroxyl group of flavonols and C4’ hydroxyl group of flavones. For the catechol moiety, an intramolecular reorganization to an o-benzoquinone-like structure occurs, and the ETPT is favored as the second abstraction mechanism.

Sign in / Sign up

Export Citation Format

Share Document