Comparative studies of excited state intramolecular proton transfer (ESIPT) and azo-hydrazone tautomerism in naphthalene-based fluorescent acid azo dyes by computational study

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Suvidha Shinde ◽  
Nagaiyan Sekar
Keyword(s):  
Molecular Orbital ◽  
Computational Study ◽  
Intramolecular Proton Transfer ◽  
Energy Band Gap ◽  
Light Fastness ◽  
Electrophilicity Index ◽  
Lumo Energy ◽  
Highest Occupied Molecular Orbital ◽  
Hardness Values ◽  
Hydrazone Form

AbstractWe found that benzothiazole is responsible for enhancing fastness properties of dyes. On comparing the total electronic energies of naphthol tautomers (−1425.16 eV) and its analogs (−2146.59 eV), we found that benzothiazolyl series is more stable than the naphthol series. Frontier Molecular Orbitals (FMOs) also show flow of charge transfer from the donor to the acceptor in benzothiazole-containing compounds, whereas it is absent in plane naphthol series. Among the benzothiazolyl isomers, the hydrazone form is found to be more stable and responsible for fluorescence possession. Highest Occupied Molecular Orbital (HOMO)–Lowest Occupied Molecular Orbital (LUMO) energy band gap also indicates the same. Electrophilicity index and hyper-hardness values of both the series were found to be positive which directly ratifies photostability and reactivity. Benzothiazolyl series was found to be more stable, hence light fastness, enhanced.

Theoretical studies on lindqvist polyoxometalates [M6O19]n−(M = Mo, W, n=2; M = V, Nb, Ta, n=8) and derivatives: Electronic structures, stability and bonding

2017 ◽  
Vol 16 (06) ◽  
pp. 1750054 ◽  
Author(s):  
Xiao-Fang Su ◽  
Bo Zhu ◽  
Cai-Xia Wu ◽  
Li-Kai Yan ◽  
Zhong-Min Su
Keyword(s):  
Charge Density ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Density Functional ◽  
Geometrical Structure ◽  
Energy Gap ◽  
Lumo Energy ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The geometrical and electronic structures of [M6O[Formula: see text]][Formula: see text] (M [Formula: see text] Mo, W, [Formula: see text]; M [Formula: see text] V, Nb, Ta, [Formula: see text]) and their derivatives were investigated by using density functional theory methods. The results indicate that the geometrical structure of [V6O[Formula: see text]][Formula: see text] is not different from other Lindqvist-type anions. The energy gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) (HOMO[Formula: see text]LUMO energy gap) of [V6O[Formula: see text]][Formula: see text] is smaller than those of same charge anions, [Nb6O[Formula: see text]][Formula: see text] and [Ta6O[Formula: see text]][Formula: see text]. In addition, the charge density [Formula: see text] of [V6O[Formula: see text]][Formula: see text] is larger when compared with those of other studied clusters. The investigation on the derivatives shows that the valence of V atom (V[Formula: see text] or V[Formula: see text]) and the methoxy ligand influence the HOMO[Formula: see text]LUMO energy gap and the charge density [Formula: see text] of the studied clusters.

scholarly journals Molecular Orbital Study of Flouroaryl Substituted Amino-Borane Dimers: Geometry, Energetics and Reactivity

2019 ◽  
Vol 31 (8) ◽  
pp. 1785-1790
Author(s):  
Shikha Gulati ◽  
Divya Lamba ◽  
H.C. Tandon
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Chemical Reactivity ◽  
Parametric Method ◽  
Geometrical Parameters ◽  
Electrophilicity Index ◽  
Lumo Energy ◽  
Molecular Orbital Study ◽  
Homo Lumo ◽  
Good Agreement

The electronic properties in terms of HOMO-LUMO energy, electronegativity, hardness and electrophilicity index have been calculated and discussed in the framework of Unrestricted Hartee-Fock (UHF), semi-emperical parametric method (PM3) for six fluoro-substituted aminoborane dimers, viz. [Me2B-μ-N(H)ArF]2 (Ar: 4-C6H4F (1), 2-C6H5F (2); 3,5-C6H3F2 (3); 2,3,4,5-C6HF4 (4); 2,3,5,6-C6HF4 (5) and C6F5 (6)). The calculated parameters mentioned above have been compared with the available experimental and other theoretical estimates. The results are in excellent agreement with the reported estimates. The geometrical parameters calculated are also in good agreement with available experimental and theoretical values. The chemical reactivity is also discussed in terms of electrophilicity index (ω) values.

Electronic State Calculation of Manganese Dioxide and Manganese-Molybdenum Oxide for Dimensionally Stable Anode

2007 ◽  
Vol 26-28 ◽  
pp. 969-972 ◽  
Author(s):  
B.S. Kim ◽  
Dong Yoon Lee ◽  
Hee Woong Lee ◽  
Won Sub Chung
Keyword(s):  
Manganese Dioxide ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Cluster Model ◽  
Manganese Atom ◽  
Orbital Method ◽  
Molecular Orbital Method ◽  
Energy Band Gap ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The effect of molybdenum substitution in electronic structures of manganese dioxide has been calculated by the DV-Xα molecular orbital method. The molybdenum atom substituted for manganese atom located in center-sited of (Mn15O56)-52 cluster model. By the molybdenum substitution the energy band gap between the highest occupied molecular orbital (HOMO) of valence band and the lowest unoccupied molecular orbital (LUMO) was decreased, also the interaction of Mn-3d and O-2p was weakened but that of Mo-4d and O-2p was intensified. Both bonds of (Mn15O56)-52 and (Mn14MoO56)-52 was composed of not only ionic but also partially covalent.

Experimental and Theoretical Study on Properties of the Fayalite Mineral in Coal Ash

2010 ◽  
Vol 156-157 ◽  
pp. 1430-1434
Author(s):  
Mei Fang Du ◽  
Gui Lin Lu ◽  
Tuo Zhou ◽  
Ning Pu Hou ◽  
Zhong Xiao Zhang ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Theoretical Study ◽  
Coal Ash ◽  
Water Cooling ◽  
Generalized Gradient ◽  
Lumo Energy ◽  
Generalized Gradient Approximation ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Physical Phenomena

This papers deals with the study of the fayalite with high content of iron in the initial layer of coal ash, using the generalized gradient approximation and Perdew-Wang91 algorithm based on the Quantum chemistry. By calculating, we found that the gap between the highest occupied molecular orbital(HOMO) energy and the lowest unoccupied molecular orbital(LUMO) energy of the Fayalite is very small, so the structure is unstable. Thus show that the water-cooling wall slagging more active due to Fe atoms,prone to transformations of physical phenomena.

Optical properties of (Z)-2-(2-phenylhydrazinylidene)acenaphthen-1(2H)-one: a potential electron donor in organic solar cells

2017 ◽  
Vol 73 (6) ◽  
pp. 458-463
Author(s):  
Yan-Xiao Su ◽  
Chao-Zhi Zhang ◽  
Ming-Xia Song
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Organic Solar Cells ◽  
Energy Gap ◽  
Lumo Energy ◽  
Face To Face ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Title Molecule ◽  
Homo Lumo

Electron-donating molecules play an important role in the development of organic solar cells. (Z)-2-(2-Phenylhydrazinylidene)acenaphthen-1(2H)-one (PDAK), C18H12N2O, was synthesized by a Schiff base reaction. The crystal structure shows that the molecules are planar and are linked together forming `face-to-face' assemblies held together by intermolecular C—H...O, π–π and C—H...π interactions. PDAK exhibits a broadband UV–Vis absorption (200–648 nm) and a low HOMO–LUMO energy gap (1.91 eV; HOMO is the highest occupied molecular orbital and LUMO is the lowest unoccupied molecular orbital), while fluorescence quenching experiments provide evidence for electron transfer from the excited state of PDAK to C60. This suggests that the title molecule may be a suitable donor for use in organic solar cells.

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

scholarly journals Electronic Properties of Triangle Molybdenum Disulfide (MoS2) Clusters with Different Sizes and Edges

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1157
Author(s):  
Songsong Wang ◽  
Changliang Han ◽  
Liuqi Ye ◽  
Guiling Zhang ◽  
Yangyang Hu ◽  
...  
Keyword(s):  
Quantum Chemistry ◽  
Electronic Properties ◽  
Absorption Spectra ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Edge States ◽  
Frontier Orbitals ◽  
Edge Structure ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The electronic structures and transition properties of three types of triangle MoS2 clusters, A (Mo edge passivated with two S atoms), B (Mo edge passivated with one S atom), and C (S edge) have been explored using quantum chemistry methods. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of B and C is larger than that of A, due to the absence of the dangling of edge S atoms. The frontier orbitals (FMOs) of A can be divided into two categories, edge states from S3p at the edge and hybrid states of Mo4d and S3p covering the whole cluster. Due to edge/corner states appearing in the FMOs of triangle MoS2 clusters, their absorption spectra show unique characteristics along with the edge structure and size.

scholarly journals Photoconductivity of Low-Bandgap Polymer and Polymer: Fullerene Bulk Heterojunction Studied by Constant Photocurrent Method

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
V. V. Malov ◽  
A. R. Tameev ◽  
S. V. Novikov ◽  
M. V. Khenkin ◽  
A. G. Kazanskii ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Bulk Heterojunction ◽  
Inorganic Materials ◽  
Fullerene Derivative ◽  
Approximation Procedure ◽  
Photoelectric Properties ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital ◽  
Doped Polymers

AbstractOptical and photoelectric properties of modern photosensitive polymers are of great interest due to their prospects for photovoltaic applications. In particular, an investigation of absorption and photoconductivity edge of these materials could provide valuable information. For these purpose we applied the constant photocurrent method which has proved its efficiency for inorganic materials. PCDTBT and PTB7 polymers were used as objects for the study as well as their blends with a fullerene derivative PC71BM. The measurements by constant photocurrent method (CPM) show that formation of bulk heterojunction (BHJ) in the blends increases photoconductivity and results in a redshift of the photocurrent edge in the doped polymers compared with that in the neat polymers. Obtained from CPM data, spectral dependences of absorption coefficient were approximated using Gaussian distribution of density-of-states within HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) bands. The approximation procedure allowed us to evaluate rather optical than electrical bandgaps for the studied materials. Moreover, spectra of polymer:PC71BM blends were fitted well by the sum of two Gaussian peaks which reveal both the transitions within the polymer and the transitions involving charge transfer states at the donor-acceptor interface in the BHJ.

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