Theoretical study on the molecular structure and vibrational properties, NBO and HOMO–LUMO analysis of the POX3 (X=F, Cl, Br, I) series of molecules

Galván, J.E.; Gil, Diego M.; Lanús, Hernán Enrique; Altabef, A. Ben

doi:10.1016/j.molstruc.2014.10.060

Cited by 11 publications

(3 citation statements)

References 31 publications

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“…It can be concluded that the best HALS in this study is Tinuvin 622 regarding its highest electrophilicity of 1.43 eV, lowest chemical hardness of 2.57 eV, and lowest chemical potential of −2.71 eV, while the worst one is Tinuvin 770 with the lowest level of reactivity. These results are in good agreement with those obtained by previous studies 36 …”

Section: Resultssupporting

confidence: 93%

Theoretical and experimental assessment of UV resistance of high‐density polyethylene: Screening and optimization of hindered amine light stabilizers

Davand

Rahimpour

Hassanajili

et al. 2021

J of Applied Polymer Sci

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Hindered amine light stabilizers (HALS) are widely used chemical stabilizers for preventing polymer degradation. In this study, the effects of type of HALS and its content in high‐density polyethylene (HDPE) over the stabilization process are investigated employing density functional theory (DFT) and experimental approach. The electrophilicity index of four types of commercial HALS are compared by DFT to select the most effective one. Besides, the HDPE sample containing a phenolic antioxidant and different contents of the selected HALS are experimentally exposed to UV irradiation. The effect of HALS content on the changes in chain microstructure and molecular weight of HDPE are evaluated using gel permeation chromatography and frequency sweep rheometry. In the absence of HALS, HDPE suffers degradation and the phenolic antioxidant causes chain scission. However, by adding HALS, the chain branching and crosslinking mechanisms are predominant. The results of FTIR, DSC, and tensile analyses follow similar trends, revealing that the best stabilization performance corresponds to adding 600 ppm HALS to HDPE.

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Section: Resultssupporting

confidence: 93%

Theoretical and experimental assessment of UV resistance of high‐density polyethylene: Screening and optimization of hindered amine light stabilizers

Davand

Rahimpour

Hassanajili

et al. 2021

J of Applied Polymer Sci

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“…In this respect, hard molecules (e.g., TEMPO and 4-amino-TEMPO) possess higher values of chemical hardness, and subsequently, larger gaps between the HOMO and LUMO, whereas soft molecules (e.g., 4-hydroxy-TEMPO and 4-oxo-TEMPO) exhibit lower values of chemical hardness and smaller gaps. The obtained results demonstrate good consistency with those reported in the previous studies [50].…”

Section: Dft Calculation Resultssupporting

confidence: 92%

A Theoretical and Experimental Study for Screening Inhibitors for Styrene Polymerization

2019

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Styrene is one of the most important monomers utilized in the synthesis of various polymers. Nevertheless, during distillation, storage, and transportation of ST, undesired polymer (i.e., UP) formation can take place. Thus, the control of undesired polymerization of styrene is a challenging issue facing industry. To tackle the mentioned issue, the antipolymer and antioxidant activity of stable nitroxide radicals (i.e., SNRs) and phenolics in styrene polymerization were studied by density functional theory (DFT) calculation and experimental approach. The electrophilicity index and growth percentage have been determined by DFT calculation and experimental approach, respectively. It is depicted that 2,6-di-tert-butyl-4-methoxyphenol (DTBMP) and 2,6-di-tert-butyl-4-methylphenol (BHT) from phenolics, and 4-hydroxy-2,2,6,6-tetramethyl piperidine 1-Oxyl (4-hydroxy-TEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine 1-Oxyl (4-oxo-TEMPO) from stable nitroxide radicals were the most effective inhibitors. Also, the growth percentage of DTMBP, BHT, 4-hydroxy-TEMPO, and 4-oxo-TEMPO after 4 h were 16.40, 42.50, 24.85, and 46.8, respectively. In addition, the conversion percentage of DTMBP, BHT, 4-hydroxy-TEMPO, and 4-oxo-TEMPO after 4 h were obtained to be 0.048, 0.111, 0.065, and 0.134, respectively. Furthermore, the synergistic effect of these inhibitors was investigated experimentally, indicating that DTMBP/4-hydroxy-TEMPO exerted the best synergistic effects on the inhibition of polymerization. The optimum inhibition effect was observed at the blend of 4-hydroxy-TEMPO (25 wt.%) and DTMBP (75 wt.%,) corresponding to 6.8% polymer growth after 4 h.

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“…A negative value of LUMO energy is equal to electron affinity (EA = -E LUMO ) (Shankar et al, 2009, Rocha et al, 2015. The chemical hardness η of the molecule based on the molecular orbital can be calculated by the following equation (equation 1) (Galván et al, 2015) η ( ) Equation 1…”

Section: Frontier Molecular Orbital (Fmo) Analysismentioning

confidence: 99%

Computational study of optical properties, and enantioselective synthesis of di-substituted esters of hydantoic and thiohydantoic acids

2020

ZJPAS

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The title compounds with different optically active substituted ester of hydantoic and thiohydantoic were synthesized by the reaction of corresponding enantio-pure amino acids methyl ester hydrochloride with phenylisocyanate/thiocyanate in the presence of triethylamine. The duration of reaction was limited to avoid racemisation and produce high enantio-enriched compounds. Low values of ELUMO-HOMO gap 0.14, 0.16, 0.15, 0.15, and 0.10 eV were observed for compounds 1, 2, 3, 4, and 5, respectively indicate soft, and high reactivity compounds. Values of ELUMO-HOMO gap also show that the compounds can easily decompose spontaneously to their elements. The order of synthesized compounds based on increasing reactivity depends on LUMO-HOMO energy gap represent as follows; 5>1>3, 4>2. Thermodynamic energies have been calculated for synthesized compounds including Enthalpy and Gibbs free energy.

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Theoretical study on the molecular structure and vibrational properties, NBO and HOMO–LUMO analysis of the POX3 (X=F, Cl, Br, I) series of molecules

Cited by 11 publications

References 31 publications

Theoretical and experimental assessment of UV resistance of high‐density polyethylene: Screening and optimization of hindered amine light stabilizers

Theoretical and experimental assessment of UV resistance of high‐density polyethylene: Screening and optimization of hindered amine light stabilizers

A Theoretical and Experimental Study for Screening Inhibitors for Styrene Polymerization

Computational study of optical properties, and enantioselective synthesis of di-substituted esters of hydantoic and thiohydantoic acids

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