Employment of quantum chemical descriptors for Hammett constants: Revision Suggested for the acetoxy substituent

Papp, Tamara; Kollár, László; Kégl, Tamás

doi:10.1016/j.cplett.2013.10.017

Cited by 22 publications

(18 citation statements)

References 32 publications

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“…Additionally, the πand σ-couplings between the attached group and the host molecule influence the amplitude of the changes. Therefore, physical quantities correlating with global charge redistribution across the bridging bond should be proper descriptors of electronic properties, in full accordance with previous studies [31,29,30].…”

Section: Introductionsupporting

confidence: 83%

“…However, being empirical it is not readily available on demand [29], and also physical insight will be missed in this approach. There are many quantum chemical descriptors correlating with σ p [27,30,31,32]. We need to determine one which best fits the stated goals, namely: be easy to calculate and straightforward to measure (to be not specific to calculation method) as well as have direct relation to electronic changes in an extended π-conjugated host molecule.…”

Section: Introductionmentioning

confidence: 99%

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Modification of optoelectronic properties of conjugated oligomers due to donor/acceptor functionalization: DFT study

et al. 2016

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A comprehensive DFT study of a set of oligo(p-phenylene vinylene) molecules is performed to understand the structural and electronic changes upon functionalization. These changes are rationalized within a model considering frontier molecular orbitals of the π-conjugated system and σ-bonding orbital by which the functional group is attached to the host molecule. Two simple scalar quantum chemical descriptors are shown to correlate with optoelectronic properties of the functionalized molecule: the electronegativity and the relative electric dipole moment of the smallest π-closed shell subsystem containing the functional group and the terminal segment of the host molecule (phenyl). Both descriptors correlate linearly with the empirical Hammett σ p constant for a set of 24 functional groups. Comparison with available experimental data on UV-Vis absorption and cyclic voltammetry is made. Observed structural changes reflect changes in the electronic density.

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Section: Introductionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Modification of optoelectronic properties of conjugated oligomers due to donor/acceptor functionalization: DFT study

et al. 2016

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“…A large number of geometrical, electrostatic, and quantum information regarding molecules can be presented by computational chemistry software. Thus, many descriptors reflect the properties of molecules and can provide insight into the chemical nature of compounds under given reaction conditions [ 7 , 8 , 9 ]. For example, the descriptors E LUMO (energy of lowest unoccupied molecular orbital) and E HOMO (highest occupied molecular orbital) reflect the molecular orbital energies [ 1 , 10 , 11 ], which play an important role in predominating many chemical reactions and determining molecular electronic transition [ 1 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

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

Fei

Mao

et al. 2018

Molecules

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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 ∑σnormalo, normalm, normalp+ 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 ∑σnormalo, normalm, normalp+ 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.

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“…The sEDA and pEDA descriptors were next modified to evaluate heteroatom or heteroatomic group incorporation effect into a cyclic systems (sEDA(II) and pEDA(II)), to estimate substituent effect caused by a double‐bonded substituent (sEDA(=) and pEDA(=)), and to determine the heteroatom incorporation effect into a ring junction position (sEDA(III) and pEDA(III)) . The sEDA and pEDA descriptors of the classical substituent effect, now often referred by us as sEDA(I) and pEDA(I), were used to study a variety of problems: aromaticity of different systems, stability and tautomerism, vibrational and nuclear magnetic resonance spectra, optical molecular switches, halogen bond problems, reaction course analysis, and general issues connected to the substituent effect …”

Section: Introductionmentioning

confidence: 99%

On the nonadditivity of the substituent effect in homo-disubstituted pyridines

Hęclik

Dobrowolski

2016

J. Phys. Org. Chem.

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The substituent effect in mono‐ and disubstituted pyridines was studied by means of the sEDA and pEDA substituent effect descriptors expressing the substituent effect on the σ‐ and π‐electron systems of the ring, respectively. The sEDA descriptors calculated for mono‐ or disubstituted pyridines can be presented as perfectly linear functions of either benzene or monosubstituted pyridine sEDA descriptors, respectively. For the pEDA descriptors, there are substantial deviations from linearity observed for both mono‐ and disubstituted systems. For the disubstituted systems, the nonadditivity of the pEDA descriptors is strongly pronounced for the substituents in the ortho‐ and para‐positions to each other while it is only weak for the meta‐located groups. For both mono‐ and disubstituted systems, there are correlations between charge at the nitrogen lone electron pair and the σ‐ and π‐electron withdrawing and donating properties of the substituent. In general, the electron charge increases with the increase of the σ‐electron donating ability but decreases with the increase of π‐electron donating ability of substituents. Again, the effects are more significant for substituents in the ortho‐ and para‐positions than in the meta‐position. The influence of the π‐electron properties of the substituent on the lone pair, belonging to σ‐electron system of pyridines, shows the presence of hyperconjugation effects in the substituted pyridines. The hyperconjugation can be also clearly observed in cross‐dependencies of the sEDA and pEDA descriptors.

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Employment of quantum chemical descriptors for Hammett constants: Revision Suggested for the acetoxy substituent

Cited by 22 publications

References 32 publications

Modification of optoelectronic properties of conjugated oligomers due to donor/acceptor functionalization: DFT study

Modification of optoelectronic properties of conjugated oligomers due to donor/acceptor functionalization: DFT study

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

On the nonadditivity of the substituent effect in homo-disubstituted pyridines

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