Journal ArticleDOI
Structural Stability in Dimer and Tetramer Clusters of l-Alanine in the Gas Phase and the Feasibility of Peptide Bond Formation
E. J. Padma Malar,P. Divya +1 more
Reads0
Chats0
TLDR
Stability in low-energy structures of the dimer and tetramer clusters of l-alanine in the gas phase is studied by accurate quantum chemical computations at the DLPNO2013-CCSD(T) level and it is found that the dispersion interaction energies have a small role in the stability of the clusters.Abstract:
Stability in low-energy structures of the dimer and tetramer clusters of l-alanine in the gas phase is studied by accurate quantum chemical computations at the DLPNO2013-CCSD(T) level. It is found that the dispersion interaction energies in the dimer (-0.3 to -0.6 kcal/mol) and in the tetramer (-1.3 to -2.5 kcal/mol) have a small role in the stability of the clusters as compared to the hydrogen bond (HB) energies -4.1 to -14.2 and -32.2 to -40.1 kcal/mol, respectively. The HB energy in the alanine cluster is obtained from the binding energy (BE) of DLPNO2013-CCSD(T)//B2PLYP/def2-TZVP by subtracting the dispersion interaction energy. Local HB energies deduced from the dimer structures are found to be suitable to estimate total HB energies in similar environments. The BEs of OH···NH and OH···OC bonds are -9.5 and -7.1 kcal/mol, respectively. This suggests that the higher clusters are formed through OH···NH bonds as they confer more stability. Analysis of bonding in the tetramer shows that the low-energy tetramer and higher clusters are formed through the OH···NH mode of hydrogen bonding, unlike the dimer which is formed through the OH···OC bond. Feasibility of the amino acid cluster to function as a precursor for polypeptide formation is examined because the orientation of the OH···NH mode of hydrogen bonding is suitable for chemical condensation. The propensity of forming coiled structures in higher clusters and thus in the polypeptides is examined based on the conformational stability in the tetramer of alanine.read more
Citations
More filters
Journal ArticleDOI
Polypeptide formation in clusters of β-alanine amino acids by single ion impact.
Patrick Rousseau,Dariusz G. Piekarski,M. Capron,Alicja Domaracka,Lamri Adoui,Fernando Martín,Fernando Martín,Manuel Alcamí,Manuel Alcamí,Sergio Díaz-Tendero,Bernd A. Huber +10 more
TL;DR: The present results show that a plausible route to polypeptides formation in space is the collision of energetic ions with small clusters of amino acids, and show that peptide bonds are efficiently formed by water molecule emission, leading to the formation of up to tetrapeptide.
Journal ArticleDOI
Structural contribution of cationic groups to water sorption in anion exchange membranes: A combined DFT and MD simulation study
Wanting Chen,Xuemei Wu,Tiantian Li,Xiaoming Yan,Yang Zhang,Xiaozhou Wang,Fan Zhang,Shouhai Zhang,Gaohong He +8 more
TL;DR: In this paper, the authors investigated the structural contributions of different cationic groups to water sorption with only experiments, and they found that water molecules tend to first fill into the free volume of the AEMs, while the equilibrium water content is the overall result of interchain interactions, hydration, and location in the hydrophilic phase.
Journal ArticleDOI
A theoretical exploration of the effect and mechanism of CO on NO2 heterogeneous reduction over carbonaceous surfaces
TL;DR: In this article, the effect and mechanism of CO presence and its adsorption mode on NO2 heterogeneous reduction reaction over a carbonaceous surfaces were analyzed using density functional theory (DFT).
Journal ArticleDOI
The effect of CO on the transformation of arsenic species: A quantum chemistry study
TL;DR: In this paper, the effect of CO on the transformation of arsenic species was explored via density functional theory (DFT), and the reaction mechanism of homogeneous and heterogeneous reactions for arsenic oxides (AsO2 and As2O3) with CO were investigated via DFT, where the geometries of reactants, intermediates, transition states and products for each reaction were optimized by using the B3LYP method in conjunction with the 6-31G(d) basis set, and the single-point energy of each structure was calculated at the B2
Journal ArticleDOI
The inhibiting water uptake mechanism of main-chain type N-spirocyclic quaternary ammonium ionene blended with polybenzimidazole as anion exchange membrane
TL;DR: In this paper , the effect of deprotonation degree and flexibility of polybenzimidazole (PBI) on the inhibiting water uptake mechanism of main-chain type N-spirocyclic quaternary ammonium ionene (SI) as anion exchange membranes (AEMs).
References
More filters
Journal ArticleDOI
Density-functional exchange-energy approximation with correct asymptotic behavior.
TL;DR: This work reports a gradient-corrected exchange-energy functional, containing only one parameter, that fits the exact Hartree-Fock exchange energies of a wide variety of atomic systems with remarkable accuracy, surpassing the performance of previous functionals containing two parameters or more.
Journal ArticleDOI
The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: two new functionals and systematic testing of four M06-class functionals and 12 other functionals
Yan Zhao,Donald G. Truhlar +1 more
TL;DR: The M06-2X meta-exchange correlation function is proposed in this paper, which is parametrized including both transition metals and nonmetals, and is a high-non-locality functional with double the amount of nonlocal exchange.
Journal ArticleDOI
The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors
TL;DR: In this paper, a direct difference method for the computation of molecular interactions has been based on a bivariational transcorrelated treatment, together with special methods for the balancing of other errors.
Journal ArticleDOI
Density-functional approximation for the correlation energy of the inhomogeneous electron gas
TL;DR: Numerical results for atoms, positive ions, and surfaces are close to the exact correlation energies, with major improvements over the original LM approximation for the ions and surfaces.
Journal ArticleDOI
The ORCA program system
TL;DR: An overview of the current possibilities of ORCA is provided and its efficiency is documents.
Related Papers (5)
Ammonia Borane Clusters: Energetics of Dihydrogen Bonding, Cooperativity, and the Role of Electrostatics
Conformational Stability of Lactonitrile-Water Complexes: An ab Initio Study
Roberto Rivelino,Sylvio Canuto +1 more