Proton affinity and proton transfer energy for selected organic molecules

2005 ◽  
Author(s):  
T. Wroblewski ◽  
L. Ziemczonek ◽  
K. Szerement ◽  
G. P. Karwasz
Keyword(s):  
Proton Transfer ◽  
Proton Affinity ◽  
Organic Molecules ◽  
Transfer Energy

scholarly journals Minimal Optimized Effective Potentials for Density Functional Theory Studies on Excited-State Proton Dissociation

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 679
Author(s):  
Pouya Partovi-Azar ◽  
Daniel Sebastiani
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Proton Transfer ◽  
Density Functional ◽  
Photochemical Reactions ◽  
Transfer Energy ◽  
Functional Theory ◽  
Effective Potentials ◽  
Proton Dissociation ◽  
Dissociation Curves

Recently, a new method [P. Partovi-Azar and D. Sebastiani, J. Chem. Phys. 152, 064101 (2020)] was proposed to increase the efficiency of proton transfer energy calculations in density functional theory by using the T1 state with additional optimized effective potentials instead of calculations at S1. In this work, we focus on proton transfer from six prototypical photoacids to neighboring water molecules and show that the reference proton dissociation curves obtained at S1 states using time-dependent density functional theory can be reproduced with a reasonable accuracy by performing T1 calculations at density functional theory level with only one additional effective potential for the acidic hydrogens. We also find that the extra effective potentials for the acidic hydrogens neither change the nature of the T1 state nor the structural properties of solvent molecules upon transfer from the acids. The presented method is not only beneficial for theoretical studies on excited state proton transfer, but we believe that it would also be useful for studying other excited state photochemical reactions.

The effect of water-mediated catalysis on the intramolecular proton-transfer reactions of the isomers of 5-chlorouracil: a theoretical study

2019 ◽  
Vol 75 (5) ◽  
pp. 554-561
Author(s):  
Jian Zhang ◽  
Xiu Li
Keyword(s):  
Proton Transfer ◽  
Density Functional ◽  
Dft Method ◽  
Intramolecular Proton Transfer ◽  
Transfer Reactions ◽  
Energy Barriers ◽  
Transfer Energy ◽  
Geometrical Structures ◽  
Proton Transfer Reactions ◽  
Mediated Catalysis

The geometrical structures and thermal energies (E), enthalpies (H) and Gibbs free energies (G) of 13 isomers of 5-chlorouracil (5ClU) in the gas and water phases were investigated using the density functional theory (DFT) method at the M06-2X/6-311++g(3df,3pd) level. The isomers of 5ClU can be microhydrated at different molecular target sites. The mono- and dihydrated forms are the most stable in both the gas and water phases, and, because of the intermolecular interactions, the hydrations lead to a degree of change in the stability trend. Two types of isomerizations were considered: the internal H—O bond rotations in which the H atom rotates 180° around the C—O bond and the intramolecular proton-transfer reactions in which an H atom is transferred between an O atom and a neighbouring N atom. The forward and backward energy barriers for isomerizations of nonhydrated 5ClU were calculated. In addition, 16 optimized transition-state structures for water-mediated catalysis on isomerizations of 5ClU were investigated. The forward and backward proton-transfer energy barriers of water-mediated catalysis on isomerizations of 5ClU were obtained. The results indicate that the catalytic effect of two H2O molecules is much greater than that of one H2O molecule in isomerizations of 5ClU.

scholarly journals NH4+ Association and Proton Transfer Reactions With a Series of Organic Molecules

2019 ◽  
Vol 7 ◽  
Author(s):  
Eva Canaval ◽  
Noora Hyttinen ◽  
Benjamin Schmidbauer ◽  
Lukas Fischer ◽  
Armin Hansel
Keyword(s):  
Proton Transfer ◽  
Organic Molecules ◽  
Transfer Reactions ◽  
Proton Transfer Reactions

Thermokinetic Proton Transfer and Ab Initio Studies of the [2H,S,O]+System. The Proton Affinity of HSO

2000 ◽  
Vol 104 (19) ◽  
pp. 4636-4647 ◽  
Author(s):  
Brian K. Decker ◽  
Nigel G. Adams ◽  
Lucia M. Babcock ◽  
T. Daniel Crawford ◽  
Henry F. Schaefer
Keyword(s):  
Proton Transfer ◽  
Ab Initio ◽  
Proton Affinity
Sign in / Sign up

Export Citation Format

Share Document