scholarly journals The Internal Relation between Quantum Chemical Descriptors and Empirical Constants of Polychlorinated Compounds

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2935 ◽  
Author(s):  
Jiangchi Fei ◽  
Qiming Mao ◽  
Lu Peng ◽  
Tiantian Ye ◽  
Yuan Yang ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Chemical Reactivity ◽  
Chemical Properties ◽  
Quantum Chemical Descriptors ◽  
Polychlorinated Naphthalenes ◽  
Empirical Constant ◽  
Intrinsic Correlation ◽  
Chemical Descriptors ◽  
The Relationship ◽  
Empirical Constants

Quantum chemical descriptors and empirical parameters are two different types of chemical parameters that play the fundamental roles in chemical reactivity and model development. However, previous studies have lacked detail regarding the relationship between quantum chemical descriptors and empirical constants. We selected polychlorinated biphenyls (PCBs) as an object to investigate the intrinsic correlation between 16 quantum chemical descriptors and Hammett constants. The results exhibited extremely high linearity for ∑ σ o ,   m ,   p + with Qxx/yy/zz, α and EHOMO based on the meta-position grouping. Polychlorinated dibenzodioxins (PCDDs) and polychlorinated naphthalenes (PCNs) congeners, as two independent compounds, validated the reliability of the relationship. The meta-substituent grouping method between ∑ σ o ,   m ,   p + and α was successfully used to predict the rate constant (k) for •OH oxidation of PCBs, as well as the octanol/water partition coefficient (logKOW) and aqueous solubility (−logSW) of PCDDs, and exhibited excellent agreement with experimental measurements. Revealing the intrinsic correlation underlying the empirical constant and quantum chemical descriptors can develop simpler and higher efficient model application in predicting the environmental behavior and chemical properties of compounds.

scholarly journals A Comparative Study of Two Quantum Chemical Descriptors in Predicting Toxicity of Aliphatic Compounds towards Tetrahymena pyriformis

2010 ◽  
Vol 2010 ◽  
pp. 1-17 ◽  
Author(s):  
Altaf Hussain Pandith ◽  
S. Giri ◽  
P. K. Chattaraj
Keyword(s):  
Quantum Chemical ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Molecular Descriptor ◽  
Tetrahymena Pyriformis ◽  
Quantitative Structure Activity Relationship ◽  
Quantum Chemical Descriptors ◽  
Data Set ◽  
Aliphatic Compounds ◽  
Chemical Descriptors

Quantum chemical parameters such as LUMO energy, HOMO energy, ionization energy (I), electron affinity (A), chemical potential (μ), hardness (η) electronegativity (χ), philicity (ωα), and electrophilicity (ω) of a series of aliphatic compounds are calculated at the B3LYP/6-31G(d) level of theory. Quantitative structure-activity relationship (QSAR) models are developed for predicting the toxicity (pIGC50) of 13 classes of aliphatic compounds, including 171 electron acceptors and 81 electron donors, towards Tetrahymena pyriformis. The multiple linear regression modeling of toxicity of these compounds is performed by using the molecular descriptor log P (1-octanol/water partition coefficient) in conjunction with two other quantum chemical descriptors, electrophilicity (ω) and energy of the lowest unoccupied molecular orbital (ELUMO). A comparison is made towards the toxicity predicting the ability of electrophilicity (ω) versus ELUMO as a global chemical reactivity descriptor in addition to log P. The former works marginally better in most cases. There is a slight improvement in the quality of regression by changing the unit of IGC50 from mg/L to molarity and by removing the racemates and the diastereoisomers from the data set.

scholarly journals Global chemical reactivity parameters for several chiral beta-blockers from Density Functional Theory Viewpoint

2016 ◽  
Vol 89 (4) ◽  
pp. 513-518 ◽  
Author(s):  
Mona Maria Talmaciu ◽  
Ede Bodoki ◽  
Radu Oprean
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Beta Blockers ◽  
Chemical Hardness ◽  
Quantum Chemical Descriptors ◽  
Chemical Structures ◽  
Coronary Syndrome ◽  
Chemical Descriptors

Background and aim.  Beta-adrenergic antagonists have been established as first line treatment in the medical management of hypertension, acute coronary syndrome and other cardiovascular diseases, as well as for the prevention of initial episodes of gastrointestinal bleeding in patients with cirrhosis and esophageal varices, glaucoma, and have recently become the main form of treatment of infantile hemangiomas.The aim of the present study is to calculate for 14 beta-blockers several quantum chemical descriptors in order to interpret various molecular properties such as electronic structure, conformation, reactivity, in the interest of determining how such descriptors could have an impact on our understanding of the experimental observations and describing various aspects of chemical binding of beta-blockers in terms of these descriptors.Methods. The 2D chemical structures of the beta-blockers (14 molecules with one stereogenic center) were cleaned in 3D, their geometry was preoptimized using the software MOPAC2012, by PM6 method, and then further refined using standard settings in MOE; HOMO and LUMO descriptors were calculated using semi-empirical molecular orbital methods AM1, MNDO and PM3, for the lowest energy conformers and the quantum chemical descriptors (HLG, electronegativity, chemical potential, hardness and softness, electrophilicity) were then calculated.Results. According to HOMO-LUMO gap and the chemical hardness the most stable compounds are alprenolol, bisoprolol and esmolol. The softness values calculated for the study molecules revolve around 0.100. Propranolol, sotalol and timolol have among the highest electrophilicity index of the studied beta-blocker molecules. Results obtained from calculations showed that acebutolol, atenolol, timolol and sotalol have the highest values for the electronegativity index. Conclusions. The future aim is to determine whether it is possible to find a valid correlation between these descriptors and the physicochemical behavior of the molecules from this class. The HLG could be correlated to the experimentally recorded electrochemical properties of the molecules. HOMO could be correlated to the observed oxidation potential, since the required voltage is related to the energy of the HOMO, because only the electron from this orbital is involved in the oxidation process.

Reactivity of fullerenes. Quantum-chemical descriptors versus curvature

1995 ◽  
Vol 338 (1-3) ◽  
pp. 293-301 ◽  
Author(s):  
K. Choho ◽  
W. Langenaeker ◽  
G. Van De Woude ◽  
P. Geerlings
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Descriptors ◽  
Chemical Descriptors

scholarly journals A QUANTUM-CHEMICAL DESCRIPTORS OF CARBONIC ANHYDRASE CA(I) INHIBITION BY AROMATIC SULFONYL AMIDES

2020 ◽  
Vol 2 (29(56)) ◽  
pp. 27-30
Author(s):  
E.N. Krylov ◽  
L.V. Virzum ◽  
I.D. Kryukova
Keyword(s):  
Nitrogen Atom ◽  
Carbonic Anhydrase ◽  
Electrostatic Potential ◽  
Quantum Chemical ◽  
Molecular Electrostatic Potential ◽  
Quantum Chemical Descriptors ◽  
Carbonic Anhydrase Inhibition ◽  
Chemical Descriptors ◽  
Quantum Parameters

The quantum parameters of aromatic sulfonylamides are determined to describe their interaction with carbonic anhydrase at the theory level M06/6-311 ++G**(SMD). The molecular electrostatic potential on the nitrogen atom in sulfamides and Hirschfeld charge on this atom have been found to appear to be adequate and determinative descriptors of carbonic anhydrase inhibition.

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