A quantum-chemical study of pesticidal activity of phenylurea derivatives. The equilibrium geometries

1984 ◽  
Vol 49 (1) ◽  
pp. 190-196
Author(s):  
Vladimír Mocko ◽  
Karol Fiedler ◽  
Jaroslav Leška
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Herbicidal Activity ◽  
Sufficient Condition ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Conformational Geometry ◽  
Equilibrium Geometries

Quantum-chemical methods have been used to study geometry of 13 phenylurea derivatives with respect to their herbicidal activity. From energy hypersurfaces of the equilibrium geometries it was possible to determine the shape and evaluate the flexibility of the molecules. An interdependence is observed between space arrangement and herbicidal activity of some derivatives. However, the exception found indicate that conformational geometry of the molecules studied does not represent a sufficient condition for their herbicidal activity.

scholarly journals A quantum chemical study on ˙Cl-initiated atmospheric degradation of acrylonitrile

RSC Advances ◽  
2017 ◽  
Vol 7 (33) ◽  
pp. 20574-20581 ◽  
Author(s):  
Jingyu Sun ◽  
Youxiang Shao ◽  
Wenzhong Wu ◽  
Yizhen Tang ◽  
Yunju Zhang ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Atmospheric Degradation ◽  
Atomic Chlorine

Degradation of acrylonitrile (CH2CHCN) by reaction with atomic chlorine was studied using quantum chemical methods.

scholarly journals A quantum chemical study on gas phase decomposition pathways of triethylgallane (TEG, Ga(C2H5)3) and tert-butylphosphine (TBP, PH2(t-C4H9)) under MOVPE conditions

2014 ◽  
Vol 16 (32) ◽  
pp. 17018-17029 ◽  
Author(s):  
Andreas Stegmüller ◽  
Phil Rosenow ◽  
Ralf Tonner
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Phase Decomposition ◽  
Chemical Methods ◽  
Decomposition Products ◽  
Elementary Reactions ◽  
Quantum Chemical Methods ◽  
Precursor Molecules

Gas phase decomposition products of MOVPE precursor molecules TEG and TBP were identified via thermodynamic and kinetic data from a catalogue of 61 elementary reactions as calculated by quantum chemical methods.

Quantum Chemical Study of Thermal Dehydrochlorination of Poly(vinyl chloride) Containing Aldehyde Groups

1995 ◽  
Vol 60 (8) ◽  
pp. 1310-1315
Author(s):  
Jaroslav Burda
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Aldehyde Group ◽  
Point Of View ◽  
Chemical Methods ◽  
Poly Vinyl Chloride ◽  
Quantum Chemical Methods ◽  
Aldehyde Groups ◽  
Force Potential

Thermal dehydrochlorination of syndiotactic oligomeric models of PVC with aldehyde groups is studied using semiempirical quantum chemical methods AM1 and MNDO. The possibility of both radical and ionic mechanism of HCl elimination is examined. From the results it follows that the homolytic detachment of chlorine from the carbon in β-position to the aldehyde group is preferred, followed by hydrogen splitting off. Hydrogen atom detachment from the carbon in α-position to the aldehyde group as the first step is found energetically less convenient. The dehydrochlorination of aldehyde-containing PVC model, especially of the first molecule from the chain, is remarkably easier in comparison with regular PVC model. However, the energetical preference is smaller for further HCl splitting off and, from the kinetic point of view, this process seems to be slower. The influence of the aldehyde group inductive effect on the driving force potential m(Ca-Cw) is apparent from the partial charge distributions.

scholarly journals Quantum-chemical study of activation of yellow phosphorus by copper(II) chloride

2016 ◽  
pp. 4-9
Author(s):  
Akyl Tulegenov ◽  
Dina Akbayeva
Keyword(s):  
Transition Metal Complexes ◽  
Quantum Chemical ◽  
Catalytic Properties ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Oxidation Reactions ◽  
Chemical Methods ◽  
Yellow Phosphorus ◽  
Quantum Chemical Methods ◽  
Molecular Cations

Catalytic properties of Cu2+ ions in oxidation reactions of P4 were investigated in present work using quantum-chemical methods. The geometric structures of several transition metal complexes were determined. The oxidation of P4 molecules in reactions with alkane hydroxide compounds by means of interaction with Cu2+ ions is substantiated based on comparative analysis of energies. The mechanism of activation of P4 molecular cations is studied. The possibility of occurrence of the reaction is shown based on thermodynamic parameters.

scholarly journals Quantum chemical study of the structure, spectroscopy and reactivity of NO + .(H 2 O) n =1−5 clusters

2018 ◽  
Vol 376 (2115) ◽  
pp. 20170152 ◽  
Author(s):  
Kirsty A. Linton ◽  
Timothy G. Wright ◽  
Nicholas A. Besley
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Ab Initio Molecular Dynamics ◽  
Structure Theory ◽  
Energy Structure ◽  
Hartree Fock ◽  
Quantum Chemical Methods ◽  
Moller Plesset

Quantum chemical methods including Møller–Plesset perturbation (MP2) theory and density functional theory (DFT) have been used to study the structure, spectroscopy and reactivity of NO + .(H 2 O) n =1−5 clusters. MP2/6-311++G** calculations are shown to describe the structure and spectroscopy of the clusters well. DFT calculations with exchange–correlation functionals with a low fraction of Hartree–Fock exchange give a binding energy of NO + .(H 2 O) that is too high and incorrectly predict the lowest energy structure of NO + .(H 2 O) 2 , and this error may be associated with a delocalization of charge onto the water molecule directly binding to NO + . Ab initio molecular dynamics (AIMD) simulations were performed to study the NO + .(H 2 O) 5 H + .(H 2 O) 4 + HONO reaction to investigate the formation of HONO from NO + .(H 2 O) 5 . Whether an intracluster reaction to form HONO is observed depends on the level of electronic structure theory used. Of note is that methods that accurately describe the relative energies of the product and reactant clusters did not show reactions on the timescales studied. This suggests that in the upper atmosphere the reaction may occur owing to the energy present in the NO + .(H 2 O) 5 complex following its formation. This article is part of the theme issue ‘Modern theoretical chemistry’.

Application of solvaton model to quantum-chemical study of influence of solvation on the chemical process NH3 + HF → NH+4 + F-

1980 ◽  
Vol 45 (8) ◽  
pp. 2308-2314 ◽  
Author(s):  
Stanislav Miertuš ◽  
Josef Bartoš
Keyword(s):  
Aqueous Medium ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Ion Pair ◽  
Polar Components ◽  
The Right ◽  
Equilibrium Geometries ◽  
Reaction Equilibrium ◽  
Influence Of Solvent

Influence of solvent (H2O) on the system NH3 + HF NH+4 + F- has been studied with the use of the solvaton model at the level of the semiempirical CNDO/2 method. The solvent has been found to cause changes in equilibrium geometries and charge distributions particularly in the polar components of the system. Hydration stabilizes much more the charged components, hence the reaction equilibrium should be shifted to the right in aqueous medium. Hydration also facilitates the proton-transfer from HF to NH3, and the ion pair H3NH+...F- should be the most stable intermediate in aqueous medium according to the calculations.

Quantum chemical study of sulfonium ylides: Structure, charge distribution and dipole moments

1980 ◽  
Vol 45 (4) ◽  
pp. 1236-1250 ◽  
Author(s):  
Vladimír Král ◽  
Zdeněk Arnold ◽  
Václav Jehlička ◽  
Otto Exner
Keyword(s):  
Ab Initio ◽  
Charge Distribution ◽  
Quantum Chemical ◽  
Dipole Moments ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Quantum Chemical Methods ◽  
Sulfonium Ylide ◽  
Experimental Values ◽  
Sulfonium Ylides

The geometry, charge distribution and dipole moments of parent sulfonium ylide - dimethylsulfoniomethylide (I) - and a series of stabilized sulfonium ylides, including 2-dimethylsulfuranylidene-1,3-cyclopentanedione (VI) prepared in this study, was investigated using the CNDO/2, PCILO and ab initio methods. Values of dipole moments, calculated by quantum chemical methods (CNDO/2 with sp and spd bases, ab initio with the STO-3G basis) as well as by the method of empirical bond moments, are compared with the experimental values determined in dioxane or benzene. Dipole moments of several related ammonium ylides were also studied.

A quantum chemical study of the acidity of acetylene and 1,2-dihydrobuckminsterfullerene de-rivatives

2018 ◽  
Vol 59 (1) ◽  
pp. 51-53
Author(s):  
M. V. Makarova ◽  
◽  
S. G. Semenov ◽  
R. R. Kostikov ◽  
◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study
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