Degradation of bromobenzene via external electric field

2020 ◽  
Vol 19 (01) ◽  
pp. 2050004 ◽  
Author(s):  
Yu Chen ◽  
Yuzhu Liu ◽  
Qihang Zhang ◽  
Yihui Yan ◽  
Wenyi Yin
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Energy Charge ◽  
Level Energy ◽  
Homo Level ◽  
Lumo Level ◽  
Dissociation Barrier

Bromobenzene is one of the organic pollutants that damage the natural environment and poses a serious threat to human health. Therefore, it is meaningful to study its degradation characteristics under the electric field. In this paper, density functional theory (DFT) at BPV86/6-311G (d, p) level are employed for the study of C–Br bond distance, total energy, charge distribution, dipole moment, lowest unoccupied molecular orbital (LUMO) level, highest occupied molecular orbital (HOMO) level, energy gap and potential energy surface (PES) of bromobenzene in external electric field ([Formula: see text]15.43[Formula: see text]V[Formula: see text][Formula: see text][Formula: see text]nm[Formula: see text]–15.43[Formula: see text]V[Formula: see text][Formula: see text][Formula: see text]nm[Formula: see text]). It shows that as the electric field increases, the C–Br bond tends to break. The changes in the HOMO level and the LUMO level result in a rapid drop in the energy gap. In addition, the dissociation barrier gradually decreases. When the applied electric field reaches 15.43[Formula: see text]V[Formula: see text][Formula: see text]nm[Formula: see text], the dissociation barrier disappears completely, which means that the C–Br bond is broken and bromobenzene is degraded.

scholarly journals Density Functional Theory Study of CL-20/Nitroimidazoles Energetic Cocrystal Compounds in an External Electric Field

2021 ◽  
Author(s):  
xiaosong Xu ◽  
Renfa Zhang ◽  
Wenxin Xia ◽  
Peng Ma ◽  
Congming Ma ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electric Field ◽  
Nitro Group ◽  
External Electric Field ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

Abstract The external electric field has a significant influence on the sensitivity of the energetic cocrystal materials. In order to find out the relationship between the external electric field and sensitivity of energetic cocrystal compounds 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/1,4-dinitroimidazole (CL-20/1,4-DNI), 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/1-methyl-2,4-dinitro-1H-imidazole (CL-20/2,4-MDNI) and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/1-methyl-4,5-dinitro-1H-imidazole (CL-20/4,5-MDNI). In this work, density functional theory (DFT) at B3LYP-D3/6-311+G(d,p) and M062X-D3/ma-def2 TZVPP levels was employed to calculate the bond dissociation energies (BDEs) of selected N-NO2 trigger bonds, frontier molecular orbitals, electrostatic potentials (ESPs) and nitro group charges (QNO2) under different external electric field. The results show that as the positive electric field intensity increases, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy gap and BDEs become smaller, and the local positive ESPs becomes larger, so that the energetic cocrystals tends to have higher sensitivity. In addition, the linear fitting results show that the trigger bond length and nitro group charge changes are closely related to the external electric field strength.

MANIPULATING PERFORMANCE OF A MOLECULAR WIRE WITH CHEMICAL MODIFICATION AND EXTERNAL ELECTRIC FIELD

2013 ◽  
Vol 12 (05) ◽  
pp. 1350040 ◽  
Author(s):  
DAVOOD FARMANZADEH ◽  
ZEINAB ASHTIANI
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Molecular Orbital ◽  
Energy Gap ◽  
The Other ◽  
Molecular Wire ◽  
Highest Occupied Molecular Orbital ◽  
Molecular Scale ◽  
Lowest Unoccupied Molecular Orbital ◽  
Geometric And Electronic Properties

In this work, a detailed theoretical investigation of the substituent groups effect on the geometric and electronic properties of the newly proposed molecular wire has been performed with the DFT-B3LYP/6-31G* level of theory by considering the influence from the external electric field (EF). The results show that the performance of molecular wire is very sensitive to the electron donating (– NH2 and – OH ), electron withdrawing (– NO2 and – F ) groups and external EF intensities. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), ELUMO–EHOMO (HLG) in all cases decreased, furthermore, the electron withdrawing – NO2 group had a much lower HLG than the other substituted groups. Results of this study indicate that the substitutions and external electric field can be used to tune the properties of a molecular scale device effectively.

Electrochemical characterization of blue-emitting polyfluorene LEP

2003 ◽  
Vol 771 ◽  
Author(s):  
Ilaria Grizzi ◽  
Clare Foden ◽  
Simon Goddard ◽  
Carl Towns
Keyword(s):  
Wave Function ◽  
Electron Affinity ◽  
Energy Gap ◽  
Polymer System ◽  
Theoretical Modelling ◽  
Level Energy ◽  
Optical Energy Gap ◽  
Experimental Conditions ◽  
Homo Level ◽  
Lumo Level

AbstractIn an operating LED, electrons are injected into the polymer's LUMO level from the cathode and holes from the anode into the polymer's HOMO level. The value of the electron affinity (EA) is usually inferred (often incorrectly) from the experimental HOMO level energy and the value of the optical band gap. Using carefully controlled experimental conditions we can now directly access the EA position. Reduction events have been observed on poly(9,9-dioctylfluorene) (F8) and blue emitting polymers based on 9,9-dioctylfluorene. This event is consistent and reversible. As predicted by theory, the LUMO level is entirely delocalised over F8 blocks. An EA of approx. –2.3eV, equal to that of F8, is therefore a common feature of blue polymers containing sequences of 9,9-dioctylfluorene. Blue emitting 9,9-dioctylfluorene -triarylamine AB copolymers containing either 4-sec-butylphenyl diphenyl amine (TFB) or N,N'-bis(4-butylphenyl)-N,N'-diphenyl phenylenediamine (PFB) are characterized by an electron affinity of –2.1eV. This result shows that the LUMO wave function in these systems is localized on the Ph-F8-Ph units. In the case of PFB homopolymer the LUMO level is again localized, this time on the biphenyl unit at the junction of each 2 repeating units. The EA for this material is therefore lower than in the previous cases: -1.84eV, as a result of the increased localization of the LUMO wave function Electrochemical characterisation provides a direct probe for the dynamic of the charge injection in a polymer system, as the HOMO and LUMO are the states into which the holes and electrons are injected. Electrochemical measurement together with theoretical modelling gives a more complete understanding of molecular properties and behaviour. However, electrochemical measurements are not necessarily relevant to the optical energy gap, as the optical excitation does not necessarily involve molecular orbitals probed by electrochemical methods.

The studies on the physical and dissociation properties of chlorobenzene under external electric fields

2018 ◽  
Vol 17 (04) ◽  
pp. 1850029 ◽  
Author(s):  
Hua Lin ◽  
Yuzhu Liu ◽  
Wenyi Yin ◽  
Yihui Yan ◽  
Luwei Ma ◽  
...  
Keyword(s):  
Electric Field ◽  
Bond Length ◽  
External Electric Field ◽  
Electric Fields ◽  
Potential Energy Curve ◽  
Energy Gap ◽  
Degradation Mechanism ◽  
Energy Curve ◽  
External Electric Fields ◽  
Dissociation Barrier

Chlorobenzene is one of the Persistent Organic Pollutants (POPs) threatening human health. It is significant to study the degradation mechanism under external electric fields. Based on the density functional theory, the physical and dissociation properties including C–Cl bond length, total energy, dipole moment, frontier orbital energy, energy gap, IR spectrum, UV-vis absorption spectrum and potential energy curve are studied under external electric fields. According to these results, it is found that the C–Cl bond length becomes longer and tends to break with the increase of external electric field and the energy gap decreases with the increase of positive as well as negative external electric field. Moreover, the dissociation barrier in potential energy curve decreases and equilibrium bond length increases with increase of positive external electric field. And when external electric field reaches 0.040 atomic units ([Formula: see text], 1 atomic [Formula: see text], the dissociation barrier disappears which means that degradation of chlorobenzene occurs under strong external electric field due to the breakage of C–Cl bond. These results provide important references for studying the degradation mechanism of chlorobenzene under strong external electric fields.

Density Functional Theory Study of Antioxidant Adsorption onto Single- Wall Boron Nitride Nanotubes: Design of New Antioxidant Delivery Systems

2019 ◽  
Vol 22 (7) ◽  
pp. 470-482
Author(s):  
Samereh Ghazanfary ◽  
Fatemeh Oroojalian ◽  
Rezvan Yazdian-Robati ◽  
Mehdi Dadmehr ◽  
Amirhossein Sahebkar
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Vitamin C ◽  
Electric Field ◽  
External Electric Field ◽  
Lipoic Acid ◽  
Density Functional ◽  
Cell Interaction ◽  
Boron Nitride Nanotubes ◽  
Functional Theory

Background: Boron Nitride Nanotubes (BNNTs) have recently emerged as an interesting field of study, because they could be used for the realization of developed, integrated and compact nanostructures to be formulated. BNNTs with similar surface morphology, alternating B and N atoms completely substitute for C atoms in a graphitic-like sheet with nearly no alterations in atomic spacing, with uniformity in dispersion in the solution, and readily applicable in biomedical applications with no obvious toxicity. Also demonstrating a good cell interaction and cell targeting. Aim and Objective: With a purpose of increasing the field of BNNT for drug delivery, a theoretical investigation of the interaction of Melatonin, Vitamin C, Glutathione and lipoic acid antioxidants using (9, 0) zigzag BNNTs is shown using density functional theory. Methods: The geometries corresponding to Melatonin, Vitamin C, Glutathione and lipoic acid and BNNT with different lengths were individually optimized with the DMOL3 program at the LDA/ DNP (fine) level of theory. Results: In the presence of external electric field Melatonin, Vitamin C, Glutathione and lipoic acid could be absorbed considerably on BNNT with lengths 22 and 29 Å, as the adsorption energy values in the presence of external electric field are considerably increased. Conclusion: The external electric field is an appropriate technique for adsorbing and storing antioxidants on BNNTs. Moreover, it is believed that applying the external electric field may be a proper method for controlling release rate of drugs.

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

scholarly journals Tipping the balance: theoretical interrogation of divergent extended heterolytic fragmentations

2020 ◽  
Vol 11 (8) ◽  
pp. 2231-2242 ◽  
Author(s):  
Croix J. Laconsay ◽  
Ka Yi Tsui ◽  
Dean J. Tantillo
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Electric Field ◽  
Ab Initio ◽  
External Electric Field ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Functional Theory

We interrogate a type of heterolytic fragmentation called a ‘divergent fragmentation’ using density functional theory (DFT), natural bond orbital (NBO) analysis, ab initio molecular dynamics (AIMD), and external electric field (EEF) calculations.

Computational and Experimental Study onthe Adsorption and Inhibition Effects of 1,3-Benzothiazol-6-ol on the Corrosion ofSteel X80 in Acidic Solution

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Iman Danaee ◽  
Paria Nikparsa ◽  
Mohammad Reza Khosravi-Nikou
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Acidic Solution ◽  
Energy Gap ◽  
Force Microscopy ◽  
Highest Occupied Molecular Orbital ◽  
Low Concentrations ◽  
Noise Data ◽  
Chemical Factors ◽  
Lowest Unoccupied Molecular Orbital

Abstract In this work, the adsorption and inhibition behavior of 1,3-benzothiazol-6-ol were investigated by computational and experimental techniques for steel X80 corrosion in acidic solution. The density functional theory was carried out and quantum chemical factors like the energy gap, energy of highest occupied molecular orbital, the energy of lowest unoccupied molecular orbital, the fraction of electron transferred, and Mulliken charges have been calculated. In addition, according to quantum calculation, S atom in 1,3-benzothiazol-6-ol indicated more tendency for electrophilic attack in adsorption. The main reason for high inhibition efficiencies in very low concentrations is the planar and simplicity of inhibitor structure which leads to increasing the efficiency of adsorption by functional group especially sulfur. Electrochemical frequency modulation and potentiodynamic polarization indicated that this material has excellent inhibiting features in very low concentrations. The influence of DC trend on the explanation of electrochemical noise data was evaluated by polynomial fitting and the optimum polynomial order m = 5 was obtained. Noise resistance and the inhibition efficiency was calculated and compared in different methods. The theory of shot noise in frequency domain was used to obtain the electrochemical event charge. The corroded surface of steel in the absence and existence of thiazole compound was studied by Atomic force microscopy.

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