scholarly journals Probing the Catalytically Active Species in POM-Catalyzed DNAmodel Hydrolysis

2020 ◽  
Author(s):  
Frederico Martins ◽  
Ángel Sanchez-Gonzalez ◽  
Jose Lanuza ◽  
Haralampos Miras ◽  
Xabier Lopez ◽  
...  
Keyword(s):  
Density Functional ◽  
Catalytic Effect ◽  
Molecular Model ◽  
Active Species ◽  
Functional Theory ◽  
Spectrometric Data ◽  
Ionisation Mass Spectrometry ◽  
Data Density ◽  
Catalytically Active ◽  
Hydrolysis Of

<div>Phosphoester hydrolysis is an important chemical step in DNA repair. One archetypal molecular model of phosphoesters is para-nitrophenylphosphate (pNPP). It has been shown previously that the presence of molecular metal oxide [Mo7O24]6– may catalyse the hydrolysis of pNPP through the partial decomposition of polyoxomolybdate framework resulting in a [(PO4)2Mo5O15]6– product. Real-time monitoring of the catalytic system using electrospray ionisation mass spectrometry (ESI-MS) provided a glance into the species present in the reaction mixture. Following up on the obtained spectrometric data, Density Functional Theory (DFT) calculations were carried out to characterise the hypothetical intermediate [Mo5O15(pNPP)2(H2O)6]6–</div><div>that would be required to form under the</div><div>hypothesised transformation. Surprisingly, our results point to the dimeric [Mo2O8]4- anion resulting from the decomposition of [Mo7O24]6– as the active catalytic species involved in the hydrolysis of pNPP rather than the originally assumed {Mo5O15} skeleton. A similar study was carried out involving the same species but substituting Mo by W. The mechanism involving W species showed a higher barrier and less stable products in agreement with the non-catalytic effect found in experimental results.</div>

scholarly journals Probing the Catalytically Active Species in POM-Catalyzed DNAmodel Hydrolysis

2020 ◽  
Author(s):  
Frederico Martins ◽  
Ángel Sanchez-Gonzalez ◽  
Jose Lanuza ◽  
Haralampos Miras ◽  
Xabier Lopez ◽  
...  
Keyword(s):  
Density Functional ◽  
Catalytic Effect ◽  
Molecular Model ◽  
Active Species ◽  
Functional Theory ◽  
Spectrometric Data ◽  
Ionisation Mass Spectrometry ◽  
Data Density ◽  
Catalytically Active ◽  
Hydrolysis Of

<div>Phosphoester hydrolysis is an important chemical step in DNA repair. One archetypal molecular model of phosphoesters is para-nitrophenylphosphate (pNPP). It has been shown previously that the presence of molecular metal oxide [Mo7O24]6– may catalyse the hydrolysis of pNPP through the partial decomposition of polyoxomolybdate framework resulting in a [(PO4)2Mo5O15]6– product. Real-time monitoring of the catalytic system using electrospray ionisation mass spectrometry (ESI-MS) provided a glance into the species present in the reaction mixture. Following up on the obtained spectrometric data, Density Functional Theory (DFT) calculations were carried out to characterise the hypothetical intermediate [Mo5O15(pNPP)2(H2O)6]6–</div><div>that would be required to form under the</div><div>hypothesised transformation. Surprisingly, our results point to the dimeric [Mo2O8]4- anion resulting from the decomposition of [Mo7O24]6– as the active catalytic species involved in the hydrolysis of pNPP rather than the originally assumed {Mo5O15} skeleton. A similar study was carried out involving the same species but substituting Mo by W. The mechanism involving W species showed a higher barrier and less stable products in agreement with the non-catalytic effect found in experimental results.</div>

DFT study on the hydrolysis of metsulfuron-methyl: A sulfonylurea herbicide

2018 ◽  
Vol 17 (08) ◽  
pp. 1850050 ◽  
Author(s):  
Qiuhan Luo ◽  
Gang Li ◽  
Junping Xiao ◽  
Chunhui Yin ◽  
Yahui He ◽  
...  
Keyword(s):  
Free Energy ◽  
Water Molecule ◽  
Carbonyl Group ◽  
Energy Barrier ◽  
Density Functional ◽  
Free Energy Barrier ◽  
Functional Theory ◽  
Metsulfuron Methyl ◽  
Catalytic Role ◽  
Hydrolysis Of

Sulfonylureas are an important group of herbicides widely used for a range of weeds and grasses control particularly in cereals. However, some of them tend to persist for years in environments. Hydrolysis is the primary pathway for their degradation. To understand the hydrolysis behavior of sulfonylurea herbicides, the hydrolysis mechanism of metsulfuron-methyl, a typical sulfonylurea, was investigated using density functional theory (DFT) at the B3LYP/6-31[Formula: see text]G(d,p) level. The hydrolysis of metsulfuron-methyl resembles nucleophilic substitution by a water molecule attacking the carbonyl group from aryl side (pathway a) or from heterocycle side (pathway b). In the direct hydrolysis, the carbonyl group is directly attacked by one water molecule to form benzene sulfonamide or heterocyclic amine; the free energy barrier is about 52–58[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. In the autocatalytic hydrolysis, with the second water molecule acting as a catalyst, the free energy barrier, which is about 43–45[Formula: see text]kcal[Formula: see text]mol[Formula: see text], is remarkably reduced by about 11[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. It is obvious that water molecules play a significant catalytic role during the hydrolysis of sulfonylureas.

DENSITY FUNCTIONAL THEORY STUDY OF H2O ADSORPTION AND DISSOCIATION ON Al (111) SURFACE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350035 ◽  
Author(s):  
LIXIA YANG ◽  
XIAOLI LEI ◽  
JUN FENG ◽  
YUXIN ZHANG ◽  
MINGXING LIU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Catalytic Effect ◽  
Geometry Optimization ◽  
Vacancy Defect ◽  
Hydroxyl Group ◽  
Dissociation Pathway ◽  
Functional Theory ◽  
Lower Activation ◽  
Adsorption And Dissociation

Comparative study about the adsorption and dissociation behaviors of H2O molecule on clean and vacancy defective Al (111) surface was conducted by extensive density functional theory (DFT) calculations, the interaction mechanisms between H2O molecule and Al (111) surface were also figured out. Geometry optimization results indicated that H2O molecule was apt to be adsorbed at top site on these two kinds of surfaces, whereas, the adsorption configurations, the adsorption type and inclination of H2O molecule planes away from the normal were different. The calculated adsorption energies demonstrated that the adsorption of H2O molecule occurred more readily on vacancy defective Al (111) surface. The electron density distribution indicated that the vacancy defect enhanced the interactions between H2O molecule and surface Al atoms. Further analysis of the density of states (DOS) showed that the vacancy defect increased the number of bonding electrons between H2O molecule and surface Al atoms. The detailed exploration of dissociation pathways demonstrated that the dissociation of H2O molecule on these two kinds of surfaces was a two-step process: (1) H2O → H + OH , (2) OH → H + O . However, for each step the dissociation pathway variations on vacancy defective Al (111) surface were different with those on clean Al (111) surface. Compared with the first step, the dissociation of hydroxyl group into O atom and H atom was kinetically difficult. The calculated lower activation energy barriers on vacancy defective Al (111) surface showed that the vacancy defect had catalytic effect for the dissociation of H2O molecule to some extent, especially for the first step.

Identifying the catalytically active sites on the layered tri-chalcogenide compounds CoPS3 and NiPS3 for efficient hydrogen evolution reaction

2021 ◽  
Author(s):  
Khorsed Alam ◽  
Tisita Das ◽  
Sudip Chakraborty ◽  
Prasenjit Sen
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Functional Theory ◽  
Catalytically Active ◽  
Structure Calculations

Electronic structure calculations based on density functional theory are used to identify the catalytically active sites for the hydrogen evolution reaction on single layers of the two transition metal tri-chalcogenide...

Catalytic Effect of Alkali and Alkaline Earth Metals in Lignin Pyrolysis: A Density Functional Theory Study

2020 ◽  
Vol 34 (8) ◽  
pp. 9734-9740 ◽  
Author(s):  
Keunhong Jeong ◽  
Hye Jin Jeong ◽  
Gunwoo Lee ◽  
Sang Hoon Kim ◽  
Kwang Ho Kim ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Alkaline Earth ◽  
Catalytic Effect ◽  
Alkaline Earth Metals ◽  
Density Functional Theory Study ◽  
Functional Theory

In Silico Alkaline Hydrolysis of Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine: Density Functional Theory Investigation

2016 ◽  
Vol 50 (18) ◽  
pp. 10039-10046 ◽  
Author(s):  
Liudmyla K. Sviatenko ◽  
Leonid Gorb ◽  
Frances C. Hill ◽  
Danuta Leszczynska ◽  
Manoj K. Shukla ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Alkaline Hydrolysis ◽  
In Silico ◽  
Density Functional ◽  
Functional Theory ◽  
Hydrolysis Of

scholarly journals Influence of the number of water molecules on the mechanism of N-sulfinylaniline hydrolysis

2005 ◽  
Vol 83 (9) ◽  
pp. 1588-1596 ◽  
Author(s):  
Elena V Ivanova ◽  
Heidi M Muchall
Keyword(s):  
Water Molecule ◽  
Density Functional ◽  
Weak Interactions ◽  
Activation Barrier ◽  
Water Molecules ◽  
Functional Theory ◽  
High Enthalpy ◽  
Rate Determining Step ◽  
Enthalpy Of Activation ◽  
Hydrolysis Of

The mechanism of the uncatalyzed hydrolysis of N-sulfinylaniline (Ph-N=S=O) has been studied with B3LYP/6-31+G(2d,2p) in the gas phase, with explicit treatment of water molecules. Hydrolysis involves water attack on sulfur, with a close to perpendicular alignment of a water molecule and the NSO plane in both prereaction complexes and transition states for the rate-determining step. Consequently, the distance of the weak S···O interaction, together with the efficiency of protonation of either nitrogen (attack across the N=S bond) or oxygen (attack across the S=O bond) atoms of the NSO group, determines the height of the activation barrier for hydrolysis. While the reaction with one water molecule is characterized by an unreasonably high enthalpy of activation, a cooperative effect from the weak interactions appears with the inclusion of a second water molecule, where both participate in the reaction, and the activation enthalpy drops significantly. The preference for attack across the S=O bond that is found in the reaction with one water molecule switches to a dominance of attack across the N=S bond in the reaction with three water molecules.Key words: N-sulfinylaniline, hydrolysis, mechanism, density functional theory (DFT).

Density functional theory study on the reaction of triazol-3-one with nitronium: direct nitration versus acidic group-induced nitration

RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25183-25191 ◽  
Author(s):  
Kuan Wang ◽  
Jian-Gang Chen ◽  
Bozhou Wang ◽  
Fengyi Liu ◽  
Zhao-Tie Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Catalytic Effect ◽  
Acid Group ◽  
Induction Effect ◽  
Density Functional Theory Study ◽  
Acidic Group ◽  
Functional Theory ◽  
The Impact

Herein, an unexpected induction effect derived from the coexisted acid group (NO3− and/or HSO4−) was proposed. The impact of the induction effect and the resulted enhanced catalytic effect on the nitration of TO was systematically demonstrated.

Sign in / Sign up

Export Citation Format

Share Document