Ab Initio and Density Functional Theory Studies of Proton Transfer Reactions in Multiple Hydrogen Bond Systems

1995 ◽  
Vol 99 (2) ◽  
pp. 592-599 ◽  
Author(s):  
Qi Zhang ◽  
Robert Bell ◽  
Thanh N. Truong
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Proton Transfer ◽  
Ab Initio ◽  
Density Functional ◽  
Transfer Reactions ◽  
Functional Theory ◽  
Multiple Hydrogen Bond ◽  
Proton Transfer Reactions

Characterization of low-barrier hydrogen bonds. 3. Hydrogen maleate. An ab initio and DFT investigation

1997 ◽  
Vol 75 (9) ◽  
pp. 1195-1202 ◽  
Author(s):  
Michael A. McAllister
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Ab Initio ◽  
Bond Energy ◽  
Density Functional ◽  
Hydrogen Bond Energy ◽  
Functional Theory ◽  
Low Barrier Hydrogen Bonds

High-level ab initio molecular orbital and density functional theory calculations predict the existence of a very short-strong hydrogen bond in the monoanion of maleic acid (hydrogen maleate). At all levels of theory (HF, MP2, BLYP, and B3LYP) except B3PW91 the potential energy surface is predicted to contain two minima, and hence resembles a double well. The barrier to proton transfer via a symmetrical transition state is calculated to be very small at all levels of theory. In all cases the calculated zero point vibrational energy available to the system is larger than the calculated barrier for proton transfer, thus the resulting hydrogen bond formed in hydrogen maleate is predicted to be symmetrical. Using the B3PW91 functional and the 6-31 + G(d,p) basis set results in a single-well potential and a symmetrically positioned hydrogen. All correlated methods predict the gas phase hydrogen bond energy to be approximately 27 kcal/mol. Effects due to solvents were estimated using solvent cavity methods. Approximating the solvent as a dielectric continuum reduces the calculated hydrogen bond energy by roughly 6 kcal/mol at all levels of theory. Keywords: low-barrier hydrogen bonds, short-strong hydrogen bonds, hydrogen maleate, ab initio, density functional theory.

Effect of electronic excitation to intermolecular proton transfer in bulk nitromethane: Tuned parameter SCC-DFTB and first principles study

2015 ◽  
Vol 14 (02) ◽  
pp. 1550013 ◽  
Author(s):  
Feng Guo ◽  
Hong Zhang ◽  
Chao-Yang Zhang ◽  
Xin-Lu Cheng ◽  
Hai-Quan Hu
Keyword(s):  
Proton Transfer ◽  
First Principles ◽  
Density Functional ◽  
Tight Binding ◽  
Transfer Reactions ◽  
Singlet Ground State ◽  
Functional Theory ◽  
Intermolecular Proton Transfer ◽  
Proton Transfer Reactions ◽  
Dynamics Simulations

To understand the reaction mechanism involving hydrogen transfers through hydrogen-bond bridge, we carried out both Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) calculations of bulk nitromethane and Density Functional Theory (DFT) calculations of singlet ground state/triplet excited state molecular nitromethane using B3LYP functional. Firstly, we tuned the repulsive parameters of the SCC-DFTB method for nitromethane with dataset calculated from DFT at B3LYP/6-311g level. The molecular dynamics simulations are carried out with tuned parameters to get the dynamical properties of the bulk nitromethane, and the static calculations are intended to give energy profile of the reaction process. These calculations indicate the excitation of nitromethane molecule making the proton transfer reactions possible, and lowering the reaction barrier.

Theoretical study of the ground and excited states of 1-methylamideanthraquinone and its complex with fluoride anion

2016 ◽  
Vol 15 (04) ◽  
pp. 1650033
Author(s):  
Bing-Qiang Wang ◽  
Xiao-Fen Yin ◽  
Yan-Yun Dong ◽  
Cai-Yun Zhang
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Proton Transfer ◽  
Density Functional ◽  
Intermolecular Hydrogen Bond ◽  
Emission Spectra ◽  
Intramolecular Proton Transfer ◽  
Fluoride Anion ◽  
Functional Theory ◽  
Intramolecular Hydrogen

We have performed a series of calculations using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) for 1-methylamideanthraquinone (MAAQ). In the S0 state of MAAQ, amide group is coplanar with anthraquinone, and an intramolecular hydrogen bond [Formula: see text] is formed. The [Formula: see text] transition has an intramolecular charge transfer character. Two stable structures (planar nMAAQ and twisted tMAAQ) have been obtained in the S1 state of MAAQ. Thereinto, nMAAQ is lower by 0.105[Formula: see text]eV than tMAAQ in energy, so nMAAQ is the dominant conformation in the S1 state of MAAQ and the emission spectra of tMAAQ cannot be observed in the solution of MAAQ. Excited state intramolecular proton transfer (ESIPT) between C[Formula: see text]O and N–H was not observed in the S1 state of MAAQ. Upon addition of fluoride anion, only twisted conformations were obtained in both S0 and S1 states of MAAQ-F[Formula: see text]. An intermolecular hydrogen bond [Formula: see text] is formed in the S0 state, and intermolecular proton transfer happens in the S1 state for MAAQ-F[Formula: see text].

Low barrier hydrogen bond in protonated proton sponge. X-ray diffraction, infrared, and theoretical ab initio and density functional theory studies

2003 ◽  
Vol 119 (8) ◽  
pp. 4313-4319 ◽  
Author(s):  
Agnieszka J. Bieńko ◽  
Zdzisław Latajka ◽  
Wanda Sawka-Dobrowolska ◽  
Lucjan Sobczyk ◽  
Valery A. Ozeryanskii ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Ab Initio ◽  
Density Functional ◽  
Proton Sponge ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

Effects of micro-hydration in proton transfer from H2S·NO+ complex to water: Ab initio and molecular dynamics study

2011 ◽  
Vol 76 (5) ◽  
pp. 585-603 ◽  
Author(s):  
Ivan Černušák ◽  
Jozef Federič ◽  
Pavel Jungwirth ◽  
Milan Uhlár
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Wave Function ◽  
Proton Transfer ◽  
Ab Initio ◽  
Density Functional ◽  
Binding Energies ◽  
Coupled Clusters ◽  
Functional Theory ◽  
Second Order Perturbation Theory

We have studied several microhydrated (H2O)n·NO+·H2S structures (n = 1–3) and their fragments using wave-function based approach (coupled-clusters including single, double and non-iterative triple substitutions – CCSD(T) and second-order perturbation theory – MP2) and also employing density functional theory (with BLYP and ωB97XD functional). MP2 energetics is very close to CCSD(T) one. Both functionals provide reasonable binding energies compared to MP2, the ωB97XD being superior to BLYP. The exploratory ab initio molecular dynamics performed on four- and five-body clusters revealed that the hydrogen bonds network and cooperativity in these systems play a crucial role in the proton transfer from H2S·NO+ to H2O and its conversion to thionitrous acid.

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