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

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.


2010 ◽  
Vol 66 (4) ◽  
pp. 451-457 ◽  
Author(s):  
Armand Budzianowski ◽  
Mariana Derzsi ◽  
Piotr J. Leszczyński ◽  
Michał K. Cyrański ◽  
Wojciech Grochala

Two polymorphs (α, β) of pyrazinium hydrogen sulfate (pyzH+HSO_4^-, abbreviated as PHS) with distinctly different hydrogen-bond types and topologies but close electronic energies have been synthesized and characterized for the first time. The α-polymorph (P212121) forms distinct blocks in which the pyzH+ and HSO_4^- ions are interconnected through a network of NH...O and OH...O hydrogen bonds. The β-form (P\bar 1) consists of infinite chains of alternating pyzH+ and HSO_4^- ions connected by NH...O and OH...N hydrogen bonds. Density functional theory (DFT) calculations indicate the possible existence of a hypothetical polar P1 form of the β-polymorph with an unusually high dipole moment.



2021 ◽  
Author(s):  
Qian Tang ◽  
Ting Huang ◽  
Ruisi Huang ◽  
Hongyu Cao ◽  
Lihao Wang ◽  
...  

Abstract The hydrogen bond formation with formic acid would affect the complementary pair of bases between uracil and adenine, but the binding modes and spectral properties of hydrogen bonds are still obscure. Density functional theory and time-dependent density functional theory were applied to investigate the intermolecular hydrogen bonds between uracil and formic acid. The reduced density gradient (RDG), bond lengths and vibration absorption frequencies revealed that the most probable uracil-formic acid (U-FA) interaction mode formed in the position c of FA and the site 1 of U, that is, the mode 1c. The theoretical parameters in excited state complexes manifested that the variety of hydrogen bond configurations led to different degrees of strengthening or weakening of molecular interaction. In the implicit solvent (water), the formations of O-H∙∙∙O in the uracil-formic acid complexes were promoted obviously. These theoretical studies would positively affect the researches of life science and medicinal chemistry.



2016 ◽  
Vol 15 (04) ◽  
pp. 1650033
Author(s):  
Bing-Qiang Wang ◽  
Xiao-Fen Yin ◽  
Yan-Yun Dong ◽  
Cai-Yun Zhang

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].



2003 ◽  
Vol 119 (8) ◽  
pp. 4313-4319 ◽  
Author(s):  
Agnieszka J. Bieńko ◽  
Zdzisław Latajka ◽  
Wanda Sawka-Dobrowolska ◽  
Lucjan Sobczyk ◽  
Valery A. Ozeryanskii ◽  
...  


2013 ◽  
Vol 91 (2) ◽  
pp. 169-175
Author(s):  
Weiping Zhang ◽  
Xiaoyu Zhang

The effects of hydration on the ground-state structural stability and excited-state hydrogen-bonding dynamics of 2′-deoxyguanosine 5′-monophosphate (dGMP) carrying different negative charges were investigated with B3LYP/6–31+G(d,p) using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods, respectively. Particularly, we not only considered the solvent effects by the polarizible continuum model (PCM), but also the first solvation shell was included explicitly. We demonstrated that the intramolecular hydrogen bond O2–H1···O3 will be weakened with the strengthening of the hydration. From the view of bond length, we can make a valid presumption that the site of negative charge will be the more preferable site of the hydration, and the preferable site may be changed because of the presence of other hydrogen bonds. Furthermore, we found that the first solvation shell had very little effect on the geometric structures except for the hydrogen bond P–O5···H5. By comparing the excitation energies, one important finding is that the changes in different electronic states are not obvious with the increase in n value when considering the PCM. Another finding is that the average interactions of hydrogen bonds may be strengthened with an increase of negative charge because of a decrease in excitation energies.



2011 ◽  
Vol 76 (5) ◽  
pp. 585-603 ◽  
Author(s):  
Ivan Černušák ◽  
Jozef Federič ◽  
Pavel Jungwirth ◽  
Milan Uhlár

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.



Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 564
Author(s):  
Beata Kizior ◽  
Jarosław J. Panek ◽  
Bartłomiej M. Szyja ◽  
Aneta Jezierska

Intra- and inter-molecular interactions were studied in 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone and 1,4-dihydroxy-anthraquinone to shed more light on the molecular assembly phenomena. The electronic ground and excited states features of the compounds were investigated to find structure-property dependencies. The theoretical study was carried out on the basis of Density Functional Theory (DFT), its Time-Dependent (TD-DFT) extension, and using Car–Parrinello Molecular Dynamics (CPMD). In order to show how the environmental effects modulate the physico-chemical properties, the simulations were performed in vacuo, with the solvent reaction field (Polarizable Continuum Model (PCM) and water as a solvent) and crystalline phase. The intramolecular hydrogen bonds and the bridged proton dynamics were analyzed in detail. The aromatic rings and electronic structure changes were estimated using the Harmonic Oscillator Model of Aromaticity (HOMA) and Atoms in Molecules (AIM) theory. The Symmetry-Adapted Perturbation Theory (SAPT) was employed for interaction energy decomposition in the studied dimers and trimers. It was found that the presence of a polar solvent decreased the energy barrier for the bridged proton transfer. However, it did not significantly affect the aromaticity and electronic structure. The SAPT results showed that the mutual polarization of the monomers in the dimer was weak and that the dispersion was responsible for most of the intermolecular attraction. The intermolecular hydrogen bonds seem to be much weaker than the intramolecular bridges. The TD-DFT results confirmed that the electronic excitations do not play any significant role in the intramolecular proton transfer. The CPMD results indicated that the protons are very labile in the hydrogen bridges. Short proton transfer and proton-sharing events were observed, and a correlation between them in the twin bridges was noticed, especially for the first investigated compound.



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