scholarly journals Study of Substituent Effect on Properties of Platinum(II) Porphyrin Semiconductor Using Density Functional Theory

2018 ◽  
Vol 18 (4) ◽  
pp. 742
Author(s):  
Harno Dwi Pranowo ◽  
Fadjar Mulya ◽  
Hafiz Aji Aziz ◽  
Grisani Ambar Santoso
Keyword(s):  
Substituent Effect ◽  
Density Functional ◽  
Geometry Optimization ◽  
Dft Method ◽  
Band Gap Energy ◽  
Functional Theory ◽  
Substituent Group ◽  
Partial Charges ◽  
Visible Spectra ◽  
Uv Visible

Study of substituent effect on properties of platinum(II) porphyrin had been performed using DFT method. The aim of the study is to investigate the effect of substituent group on the electronic and optical properties of the platinum(II) porphyrin. Geometry optimization was conducted using DFT/B3LYP/LANL2DZ to obtain molecular structure, electronic structure and energy profile. Band gap energy (Eg), the density of states (DOS), and UV-visible spectra are the semiconductor parameters to study. Computational results show that platinum(II) porphyrin and substituted platinum(II) porphyrin have properties of semiconductor based on Eg value, DOS, and UV-visible spectra. The results show that Mulliken partial charges of electron withdrawing substituents are higher than the electron donating substituents (CH3, OH, and NH2). Eg values of the complexes with respect to the substituents follow this order: NH2 < OH < NO2 < COOH < I < CH3 < Br < F < H, for DOSHOMO values, the order is CH3 < NO2 < I < OH < F < NH2 < COOH < Br < H and the maximum wavelength (λmax) for UV-visible adsorption spectra follows this order: NH2 > OH > COOH > NO2 > I > Br > CH3 > F > H. Molecules with smaller Eg and DOSHOMO values and higher λmax are considered as the most appropriate semiconductor materials. Our results show that Pt(II)P-NH2 has the smallest Eg and the highest λmax among other substituted platinum(II) porphyrin molecules. Therefore, Pt(II)P-NH2 are the most suitable semiconductor material based on the aforementioned criteria.

scholarly journals Investigating Functional Performance and Substituent Effect in Modelling Molecular Structure, UV-Visible Spectra and Optical Properties of D-π-A Conjugated Organic Dye Molecules: A DFT and TD-DFT Study.

2021 ◽  
Author(s):  
Garima Chanana ◽  
Kriti Batra
Keyword(s):  
Molecular Structure ◽  
Density Functional Theory ◽  
Density Functional ◽  
Organic Dye ◽  
Dye Molecules ◽  
Functional Theory ◽  
Donor And Acceptor ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible

Abstract The molecular structure, UV-Visible spectra, and optical properties of D-π-A conjugated organic dye molecules (Disperse Red 1 (DR1) and Disperse Red 73 (DR73)) were analyzed using Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) and compared with Azobenzene molecule to study the effect of Donor and Acceptor substituents on the molecular properties. The performance of DFT functionals is investigated using B3LYP hybrid functional and three long-range corrected functionals (CAM-B3LYP, LC-ωPBE, and ωB97XD) in conjunction with 6-31G(d,p) basis set. Using TD-DFT, we calculate the vertical excitation energies and transition dipole moment values for 100 excited states. These values were further utilized to calculate frequency dependent polarizability under Sum-Over-States (SOS) formalism and refractive index of these molecular systems. We observe that for Azobenzene and DR1 molecules, ωB97XD predicted wavelengths corresponding to peak absorbance closest to the experimental results, while for DR73 molecule, B3LYP gave better prediction. Large polarizability response is also observed for these molecules (DR1 and DR73) in comparison to parent Azobenzene structure due to charge transfer between donor and acceptor groups. For DR1 and DR73 molecules, αxx component of polarizability dominates in contrast to azobenzene where αzz dominates. The HOMO→LUMO transition during excitation contributes to the peak molecular response in simulated UV-Visible spectra. The high polarizability response of selected D-π-A conjugated molecules in comparison to parent molecule suggests that these molecules are promising candidates for tailor-made photonic and optoelectronic device development

Green Synthesis of Triazole-Based Chemosensors and their Efficacy Towards Mercury Sensing

2020 ◽  
Vol 16 (6) ◽  
pp. 738-743 ◽  
Author(s):  
Poonam Rani ◽  
Kashmiri Lal ◽  
Vikas D. Ghule ◽  
Rahul Shrivastava
Keyword(s):  
Detection Limit ◽  
Metal Ions ◽  
Density Functional ◽  
Organic Molecules ◽  
Functional Theory ◽  
Small Organic Molecules ◽  
Industrial Activities ◽  
Binding Stoichiometry ◽  
Visible Spectra ◽  
Uv Visible

Background: The synthesis of small organic molecules based Hg2+ ions receptors have gained considerable attention because it is one of the most prevalent toxic metals which is continuously discharged into the environment by different natural and industrial activities. 1,4-Disubstituted 1,2,3-triazoles have been reported as good chemosensors for the detection of various metal ions including Hg2+ ions. Methods: The synthesis of 1,2,3-triazoles (4a-4c) was achieved by Cu(I)-catalyzed azide-alkyne cycloaddition, and their binding affinity towards various metal ions and anions were studied by UVVisible titration experiments. The perchlorate salts of metal ions and tetrabutylammonium salts of anions were utilized for the UV-Visible experiments. DFT studies were performed to understand the binding and mechanism on the sensing of 4a toward Hg2+ using the B3LYP/6-311G(d,p) method for 4a and B3LYP/LANL2DZ for 4a-Hg2+ species on the Gaussian 09W program. Results: The UV-visible experiments indicated that the compounds 4a-4c show a selective response towards Hg2+ ion in UV-Visible spectra, while other ions did not display such changes in the absorption spectra. The binding stoichiometry was evaluated by Job’s plot which indicated the 1:1 binding stoichiometry between receptors (4a-4c) and Hg2+ ion. The detection limit of 4a, 4b and 4c for the Hg2+ ions was found to be 29.1 nM, 3.5 μM and 1.34 μM, respectively. Conclusion: Some 1,2,3-triazole derivatives were synthesized (4a-4c) exhibiting high selectively and sensitivity towards Hg2+ ions in preference to other ions. Compound 4a has a low detection limit of 29.1 nM and the binding constant of 2.3×106 M-1. Similarly, 4b and 4c also showed selective sensing towards Hg2+ ions in the μM range. The observed experimental results were corroborated by density functional theory (DFT) calculations.

Role of heteroatoms and substituents on the structure, reactivity, aromaticity, and absorption spectra of pyrene: a density functional theory study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bapan Saha ◽  
Pradip Kumar Bhattacharyya
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Density Functional ◽  
Structural Parameters ◽  
Visible Absorption ◽  
Functional Theory ◽  
Solvent Phase ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible

Abstract Effect of heteroatoms viz. BN and substituents viz. –Me (methyl), –OH (hydroxyl), –NH2 (amine), –COOH (carboxyl), and –CN (cyano) on the structural parameters, global reactivity, aromaticity, and UV-visible spectra of pyrene are studied with the help of density functional theory (DFT). Global reactivity parameters such as global hardness (η) and electrophilicity (ω) are calculated using density functional reactivity theory (DFRT). Time dependent density functional theory (TD-DFT) is explored for interpreting the UV-visible absorption spectra. Aromaticity of the pyrene rings are predicted from the nucleus independent chemical shift (NICS) values. Presence of BN unit and substituent induces reasonable impact on the studied parameters. The observed absorption spectra lie predominantly within the UV-region (both blue and red shifts are observed in presence of BN and substituent). HOMO energy and absorption spectra are affected nominally in solvent phase.

scholarly journals Ultrasound Assisted Synthesis, Molecular Structure,UV-Visible Assignments, MEP and Mulliken Charges Study of (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl) prop-2-en-1-one: Experimental and DFT Correlational

2021 ◽  
Vol 18 (1) ◽  
pp. 86-96
Author(s):  
Rohit S. Shinde
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Uv Visible

Present investigation deals with the synthesis and density functional theory study (DFT) of a chalcone derivative; (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (CPMPP). The synthesis of a CPMPP has been carried out by the reaction of 4-methoxyacetophenone and 4-chlorobenzalehyde in ethanol at 30 ℃ under ultrasound irradiation. The structure of a synthesized chalcone is affirmed on the basis of FT-IT, 1H NMR and 13C NMR. The geometry of a CPMPP is optimized by using the density functional theory method at the B3LYP/6-31G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. The absorption energies, oscillator strength, and electronic transitions have been derived at the TD-DFT method at the B3LYP/6-31G(d,p) level of theory for B3LYP/6-31G(d p) optimized geometries. The effect of polarity on the absorption energies is discussed by computing UV-visible results in dichloromethane (DCM). Since theoretically obtained wavenumbers are typically higher than experimental wavenumbers, computed wavenumbers were scaled with a scaling factor, and vibrational assignments were made by comparing experimental wavenumbers to scaled theoretical wavenumbers. Quantum chemical parameters have been determined and examined. Molecular electrostatic potential (MEP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

Time dependent-density functional theory (TD-DFT) and experimental studies of UV–Visible spectra and cyclic voltammetry for Cu(II) complex with Et2DTC

2018 ◽  
Vol 1157 ◽  
pp. 463-468 ◽  
Author(s):  
Eliana Maira A. Valle ◽  
Vinicius Gonçalves Maltarollo ◽  
Michell O. Almeida ◽  
Kathia Maria Honorio ◽  
Mauro Coelho dos Santos ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cyclic Voltammetry ◽  
Density Functional ◽  
Experimental Studies ◽  
Time Dependent ◽  
Functional Theory ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible ◽  
Dependent Density

TD-DFT benchmark for UV-visible spectra of fused-ring electron acceptors using global and range-separated hybrids

2020 ◽  
Vol 22 (15) ◽  
pp. 7864-7874 ◽  
Author(s):  
Amjad Ali ◽  
Muhammad Imran Rafiq ◽  
Zhuohan Zhang ◽  
Jinru Cao ◽  
Renyong Geng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Acceptors ◽  
Time Dependent ◽  
Functional Theory ◽  
Visible Spectra ◽  
Td Dft ◽  
Fused Ring ◽  
Uv Visible ◽  
Dependent Density

The accuracy of Time-Dependent Density Functional Theory in predicting the vertical absorption wavelength of 50 widely-used fused-ring electron acceptors (FREAs) has been investigated by considering the solvent effects.

scholarly journals Molecular Structures and Spectral Properties of Natural Indigo and Indirubin: Experimental and DFT Studies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3831 ◽  
Author(s):  
Zixin Ju ◽  
Jie Sun ◽  
Yanping Liu
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Dft Method ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible

This paper presents a comparative study on natural indigo and indirubin in terms of molecular structures and spectral properties by using both computational and experimental methods. The spectral properties were analyzed with Fourier transform infrared (FTIR), Raman, UV-Visible, and fluorescence techniques. The density functional theory (DFT) method with B3LYP using 6-311G(d,p) basis set was utilized to obtain their optimized geometric structures and calculate the molecular electrostatic potential, frontier molecular orbitals, FTIR, and Raman spectra. The single-excitation configuration interaction (CIS), time-dependent density functional theory (TD-DFT), and polarization continuum model (PCM) were used to optimize the excited state structure and calculate the UV-Visible absorption and fluorescence spectra of the two molecules at B3LYP/6-311G(d,p) level. The results showed that all computational spectra agreed well with the experimental results. It was found that the same vibrational mode presents a lower frequency in indigo than that in indirubin. The frontier molecular orbital analysis demonstrated that the UV-Visible absorption and fluorescence bands of indigo and indirubin are mainly derived from π → π* transition. The results also implied that the indigo molecule is more conjugated and planar than indirubin, thereby exhibiting a longer maximum absorption wavelength and stronger fluorescence peak.

scholarly journals Structural, Electronic and Optical properties of the Inorganic Solar Perovskites XPbBr3 (X= Li or Na)

2021 ◽  
Author(s):  
Samira Idrissi ◽  
lahoucine bahmad ◽  
a benyssef
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Dft Method ◽  
Lattice Parameter ◽  
Band Gap Energy ◽  
Partial Density ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Quantum Espresso

In this paper, we study the structural, electronic and optical properties of the inorganic solar perovskites XPbBr3 (X= Li or Na). We applied the two methods: the density functional theory (DFT) and time-dependent density-functional theory (TDDFT). In fact, we performed the DFT method using the Quantum Espresso package. Also, the total energies of the studied inorganic solar perovskites XPbBr3 (X= Li or Na) have been deduced as a function of the lattice parameter a (Å). The two calculation methods have been carried out under the GGA-PBE and GGA-PBESol approximations. Moreover, the total and partial density of states (DOS) and the band structure of the studied compounds have been presented and discussed for the two cases: with and without the spin orbit coupling (SOC) approximation. In addition, the DFT and TDDFT have been explored in order to elaborate the structural, the electronic and the optical properties of the inorganic perovskite CsPbI3 material for solar cell applications. When using the GGA-PBESol method without SOC approximation, we found a band gap energy value greater than that one computed when adding the SOC correction. On the other hand, the optical properties of the studied material have been studied. In particular, we found that the inorganic solar Perovskite XPbBr3 (X=Li or Na) materials exhibit a high transparency of the electromagnetic radiations in energy range between 0 eV and 33 eV.

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