The Influence of the Substitution of Transition Metals on Pristine C20: A DFT Study

2018 ◽  
Vol 17 (04) ◽  
pp. 1760026 ◽  
Author(s):  
Debolina Paul ◽  
Jyotirmoy Deb ◽  
Barnali Bhattacharya ◽  
Utpal Sarkar
Keyword(s):  
Density Functional ◽  
Chemical Potential ◽  
Energy Gap ◽  
Electronic Absorption Spectra ◽  
Wavelength Region ◽  
Chemical Hardness ◽  
Theory Approach ◽  
Functional Theory ◽  
Spectra Analysis ◽  
Doped Fullerenes

The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structures of C[Formula: see text] fullerene have been investigated by density functional theory approach. We have observed a noticeable structural change in pristine C[Formula: see text] due to the substitution of one of its carbon atom by Cu or Zn atom. From our findings, it is found that the energy gap of C[Formula: see text]Cu and C[Formula: see text]Zn increases with respect to pristine C[Formula: see text], thus making the two doped fullerenes more stable than their pristine counterpart. The reactivity parameters such as chemical hardness, chemical potential and electrophilicity index for these structures are also studied. Interestingly, our calculations reveal that both the doped fullerenes obey the maximum hardness principle and minimum electrophilicity principle. Also, from the electronic absorption spectra analysis, it can be inferred that the maximum absorption peak of the two heteroatom-substituted fullerenes C[Formula: see text]Cu and C[Formula: see text]Zn are shifted towards the longer wavelength region as compared to the pure C[Formula: see text] fullerene, which clearly indicates that a red shift is introduced on account of doping.

scholarly journals Spectroscopic and Electrochemical Investigations of New 5-oxo-2- Phenyloxazol-4(5H)-ylidene Based Triazine Derivatives

2019 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Electronic Absorption Spectra ◽  
Spectroscopic Properties ◽  
Functional Theory ◽  
Structural Framework ◽  
Triazine Derivatives ◽  
Homo And Lumo ◽  
Cyclic Voltammetry Analysis ◽  
Oxazolone Ring

The present study reports the two step synthesis of a novel oxazolone derivative, 4-((4,6-bis(4-((Z)-(5-oxo-2-phenyloxazol-4(5H)-ylidene) methyl)phenoxy)-1,3,5-triazin-2-yl) oxy) benzaldehyde (CBOZ (5)), containing two oxazolone ring substituted with central triazine nucleus in their structural framework. The structural and spectroscopic properties of synthesized CBOZ (5) were characterized by FTIR, 1HNMR, 13CNMR, and mass spectroscopic analysis. The UV-Vis absorption of CBOZ (5) showed a single absorption band at ~370 nm due to π-π* transition with the estimated energy gap of ~3.02 eV. Cyclic voltammetry analysis revealed that the synthesized CBOZ (5) obtained the HOMO and LUMO values of -5.87 eV and-2.85 eV, respectively. Density functional theory (DFT) studies were carried out to predict the electronic absorption spectra of CBOZ (5) and the obtained values were in excellent agreement with the experimental results.

scholarly journals A DFT Study of the Impact of Doping on the Electronic and Optical Properties of Indium Nitride Nanocage

2021 ◽  
Author(s):  
Amarjyoti Das ◽  
Rajesh Kumar Yadav
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Density Functional ◽  
Chemical Potential ◽  
Energy Gap ◽  
Indium Nitride ◽  
Wavelength Region ◽  
Binding Energies ◽  
Electronic And Optical Properties ◽  
The Impact

Abstract Density functional theory (DFT) calculations are used to investigate the structural, electronic, and optical properties of the significant fullerene-like cage of In12N12 nanoclusters with Zn (group II) and Si (group IV) dopants. In terms of formation energies and binding energies, the structural stability of the nanocages were studied. It has been seen that stability of the structure is slightly increases with the inclusion of doping. The study found that both the dopants significantly reduce the energy gap of the In12N12 nanocluster. The electronic properties of the In12N12 nanocluster seems to be sensitive to dopants, and it could be altered by a specific impurity. Moreover, electronic properties such as density of states (DOS) analysis, dipole moment, HOMO energies, LUMO energies, energy gaps, chemical potential, electron affinity, ionization potential, hardness, and electrophilicity index are also discussed. The optical absorption spectra of pure and doped nanocages were computed using TDDFT formalism. The maximum wavelength of the pure In12N12 nanocage is moved towards higher wavelength region within the infrared region after doping with Zn and Si, indicating a redshift.

A Density Functional Theory Study on the Structures and Electronic Properties of XAln (X = Br, I; n = 3–15) Clusters

2019 ◽  
Vol 74 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Ming Hui ◽  
Qing-Huai Zhao ◽  
Zhi-Peng Wang ◽  
Shuai Zhang ◽  
Gen-Quan Li
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Three Dimensional ◽  
Density Functional Theory Calculations ◽  
Chemical Hardness ◽  
Geometrical Structures ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractThe effects of halogen element X (X = Br, I) doping on the geometrical structures and electronic properties of neutral aluminium clusters are systematically studied by utilising the density functional theory calculations. The structures of X-doped clusters show the three-dimensional forms with increasing atomic number except for n = 3 and X (X = Br, I) atom prefer to occupy the surface site of the host Aln clusters. BrAl7 and IAl7 clusters are the most stable geometries. The HOMO-LUMO energy gap and chemical hardness show an odd–even alternative phenomenon. The charges always transfer from the Al atoms to the X (X = Br, I) atom. Finally, the dipole and polarisability are discussed.

scholarly journals Density functional theory study of molecular structure, Electronic properties, UV–Vis spectra on coumarin102.

2016 ◽  
Vol 13 (2) ◽  
pp. 143-152
Author(s):  
Baghdad Science Journal
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Potential ◽  
Energy Gap ◽  
Spectral Characteristics ◽  
Functional Model ◽  
Electronic States ◽  
Basis Set ◽  
Uv Spectrum ◽  
Functional Theory

The various properties of the ground and excited electronic states of coumarins 102 using density functional theory (DFT) and time-dependent density functional theory (TDDFT) was calculated by the B3LYP density functional model with 6-31G(d,p) basis set by Gaussian 09 W program. Spectral characteristics of coumarin102 have been probed into by methods of experimental UV-visible, and quantum chemistry. The UV spectrum was measured in methanol. The optimized structures, total energies, electronic states (HOMO- LUMO), energy gap, ionization potentials, electron affinities, chemical potential, global hardness, softness, global electrophilictity, and dipole moment were measured. We find good agreement between experimental data of UV spectrum and TDDFT excitationenergies.

scholarly journals Density Functional Theory Investigation of the Doping Effects of Bromine and Fluorine on the Electronic and Optical Properties of Neutral and Ionic Perylene

2021 ◽  
pp. 1-13
Author(s):  
Auwal A. Abubakar ◽  
A. B. Suleiman ◽  
A. S. Gidado
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Chemical Hardness ◽  
Functional Theory ◽  
Bond Lengths ◽  
Hybrid Molecules ◽  
Non Linear ◽  
Linear Optical Properties

Perylene and its derivatives are some of the promising organic semiconductors. They have found vast applications in many areas such as photovoltaic systems, organic light-emitting diodes, and so on. The instability of organic molecules under ambient conditions is one factor deterring the commercialization of organic semiconductor devices. Currently, most of the investigation of Perylene and its derivatives concentrated on its diimide and bisimide derivatives. In this work, an investigation of the effects of doping Bromine and Fluorine on the electronic and non-linear optical properties was carried out based on Density Functional Theory (DFT) as implemented in the Gaussian 09 software package. We computed the Molecular geometries of the molecules, HOMO-LUMO energy gap, global chemical indices and non-linear optical properties using the same method. The bond lengths and angles of the mono-halogenated molecules at different charge states were found to be less than that of the isolated Perylene. 1-fluoroperylene was found to be the most stable amongst the studied molecule for having the least bond angles and bond lengths. In the calculation of the energy bandgap neutral 1-fluoroperylene was observed to have the highest energy gap 3.0414 eV and 3.0507 eV for 6-31++G(d,p) and 6-311++G(d,p) basis sets respectively. These results were found to agree with the existing literature. This reconfirmed 1-fluoroperylene as the most stable molecule. The computations of the ionic molecules reported small values of the energy gap. The molecule with the most chemical hardness was obtained to be the neutral 1-fluoroperylene with a chemical hardness of 1.5253eV. All the ionic molecules results were found to be more reactive than their neutral form for having lower values of chemical hardness. For NLO calculations, the results showed an increment in their values with the ionic hybrid molecules having the largest values.  In the case of first-order hyper-polarizability, 1-bromoperylene (neutral), 1-fluoroperylene (neutral), 1-bromoperylene (anionic), 1-fluoroperylene (anionic), 1-bromoperylene (cationic) and 1-fluoroperylene (cationic) were found to be 73.93%, 1.71%, 83.9%, 39.2%,38.7% and 41.7% larger than that of Urea respectively. These calculated results make these hybrid molecules suitable for a wide range of optoelectronic applications.

Combined experimental and theoretical studies on 4-(2-hydroxy-3-morpholin-4-yl-propoxy)-chromen-2-one

2016 ◽  
Vol 15 (02) ◽  
pp. 1650017
Author(s):  
Priyanka ◽  
Sanjay Kumar Srivastava ◽  
Diksha Katiyar
Keyword(s):  
Density Functional ◽  
Chemical Potential ◽  
Chemical Shifts ◽  
Basis Set ◽  
Chemical Hardness ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Hartree Fock ◽  
Homo And Lumo ◽  
Experimental And Theoretical Studies

The FTIR, UV–Vis and NMR spectra of 4-(2-hydroxy-3-morpholin-4-yl-propoxy)-chromen-2-one (4-HMPC) have been recorded and analyzed. The optimized geometry and harmonic vibrational frequencies of 4-HMPC were obtained by the Hartree–Fock (HF) and density functional theory (DFT) using B3LYP functional with 6-311[Formula: see text]G basis set. The 1H and [Formula: see text]C NMR chemical shifts were calculated by the GIAO method in chloroform. The absorption spectra of 4-HMPC were computed in ethanol and water solutions using TD-B3LYP/6-311[Formula: see text]G(d,p) approach. The correlation of theoretical and experimental results provides a detailed description of the structural and physicochemical properties of the molecule. The results obtained from the studies of HOMO and LUMO were used to calculate the conceptual-DFT-based global reactivity descriptors such as electronic chemical potential, electronegativity, chemical hardness, global softness and electrophilicity index of the compound.

C60 as Electron Acceptor and Donor: A Comparative DFT Study of Li@C60 and F@C60

2018 ◽  
Vol 71 (12) ◽  
pp. 953 ◽  
Author(s):  
Ambrish Kumar Srivastava ◽  
Sarvesh Kumar Pandey ◽  
Anoop Kumar Pandey ◽  
Neeraj Misra
Keyword(s):  
Charge Transfer ◽  
Electron Acceptor ◽  
Density Functional ◽  
Energy Gap ◽  
Orbital Energy ◽  
Prototype System ◽  
Theory Approach ◽  
Frontier Orbital ◽  
Functional Theory ◽  
Fundamental Properties

Fullerene (C60) is a stable prototype system for a special class of nanomaterials. In this work, the smallest alkali metal (Li) and halogen (F) atoms were encapsulated in the C60 cage, and comparative quantum chemical calculations (QCCs) were performed on their various properties using a density functional theory approach. It was noted that the off-centre distance of Li is higher than that of F. The QCCs of the charge transfer to and from C60 were also analysed. Although charge transfer to and from the C60 cage takes place in both cases, Li@C60 becomes more polar than F@C60, suggesting a better electron-accepting nature of C60 than electron-donating behaviour. This fact is consistent with the natural bond orbital (NBO) charge on the trapped atoms and the dipole moment as well as the binding energy values of the encapsulated C60. Although the encapsulation of both atoms reduces the frontier orbital energy gap, the frontier orbital gap of Li@C60 is smaller than that of F@C60. More interestingly, the depression in the polarizability of Li@C60 is significantly large relative to that of F@C60. These findings also support the tendency of C60 to act as electron acceptor. This study provides some insights into the fundamental properties of C60 and should be helpful in designing new endofullerene complexes for a variety of applications.

scholarly journals Physicochemical, antioxidant properties of carotenoids and its optoelectronic and interaction studies with chlorophyll pigments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ruby Srivastava
Keyword(s):  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Antioxidant Properties ◽  
Visible Region ◽  
State Theory ◽  
Chemical Hardness ◽  
Functional Theory

AbstractThe physicochemical and antioxidant properties of seven carotenoids: antheraxanthin, β-carotene, neoxanthin, peridinin, violaxanthin, xanthrophyll and zeaxanthin were studied by theoretical means. Then the Optoelectronic properties and interaction of chlorophyll-carotenoid complexes are analysed by TDDFT and IGMPLOT. Global reactivity descriptors for carotenoids and chlorophyll (Chla, Chlb) are calculated via conceptual density functional theory (CDFT). The higher HOMO–LUMO (HL) gap indicated structural stability of carotenoid, chlorophyll and chlorophyll-carotenoid complexes. The chemical hardness for carotenoids and Chlorophyll is found to be lower in the solvent medium than in the gas phase. Results showed that carotenoids can be used as good reactive nucleophile due to lower µ and ω. As proton affinities (PAs) are much lower than the bond dissociation enthalpies (BDEs), it is anticipated that direct antioxidant activity in these carotenoids is mainly due to the sequential proton loss electron transfer (SPLET) mechanism with dominant solvent effects. Also lower PAs of carotenoid suggest that antioxidant activity by the SPLET mechanism should be a result of a balance between proclivities to transfer protons. Reaction rate constant with Transition-State Theory (TST) were estimated for carotenoid-Chlorophyll complexes in gas phase. Time dependent Density Functional Theory (TDDFT) showed that all the chlorophyll (Chla, Chlb)–carotenoid complexes show absorption wavelength in the visible region. The lower S1–T1 adiabatic energy gap indicated ISC transition from S1 to T1 state.

THEORETICAL STUDIES ON THE CONFORMATION AND COORDINATION OF N-(1-PHENYL-3-METHYL-4-PROPENYLIDENE-5-PYRAZOLONE)-SALICYLIDENE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350036
Author(s):  
ANJIE LIU ◽  
YINLING YANG ◽  
DIANZENG JIA ◽  
DONGLING WU ◽  
LANG LIU ◽  
...  
Keyword(s):  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Dft Calculation ◽  
Chemical Potential ◽  
Chemical Hardness ◽  
Theoretical Studies ◽  
Electrophilic Attack ◽  
Functional Theory ◽  
Global Indices ◽  
The Stability

Density functional theory (DFT) calculation has been carried out to investigate the isomers of N -(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-salicylidene. Chemical potential, chemical hardness and global electrophilicity, which are considered as global indices, have been calculated to assess the stability and reactivity of the tautomers. The condensed Fukui function is calculated for predicting the most probable sites for electrophilic attack. Molecular electrostatic potential is calculated to predict the regions for electrophilic attack.

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