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 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

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.

Density functional theory investigation of the effect of axial coordination and annelation on the absorption spectroscopy of nickel(II) and vanadyl porphyrins relevant to bitumen and crude oils

2013 ◽  
Vol 91 (9) ◽  
pp. 872-878 ◽  
Author(s):  
Stanislav R. Stoyanov ◽  
Cindy-Xing Yin ◽  
Murray R. Gray ◽  
Jeffrey M. Stryker ◽  
Sergey Gusarov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Polyaromatic Hydrocarbons ◽  
Geometry Optimization ◽  
Soret Band ◽  
Heavy Oils ◽  
Visible Absorption ◽  
Functional Theory ◽  
Axial Coordination ◽  
Td Dft

The vanadium and nickel components in heavy oils and bitumen are important impurities in catalytic processing and form aggregates with other asphaltene components. Metalloporphyrins are commonly analyzed using the characteristic Soret band in the UV–vis absorption spectrum. However, the Soret band of metalloporphyrins in petroleum is broadened and weaker than expected based on the concentration of Ni and V in heavy oils and the extinction coefficients of isolated porphyrins. We hypothesize that the low intensity and broadening of the Soret band could be due to axial coordination of the metal center or fusion (annelation) of aromatic rings on the porphyrin π-system. This hypothesis is examined using the density functional theory for geometry optimization and time-dependent density functional theory (TD-DFT) for calculation of excited states of nickel(II) and vanadyl porphyrins with axially coordinated ligands and annelated polyaromatic hydrocarbons. Predictions of the excited electronic states performed using the tandem of TD-DFT and conductor-like polarizable continuum model of solvation support this hypothesis and provide insight into the extent of Soret band broadening and intensity decrease due to coordination and annelation. These computational results, validated with respect to visible absorption spectra, are important for understanding asphaltene aggregation and spectroscopic characterization and suggest methods for removal of transition metals from heavy oil.

UV/Visible spectra of natural polyphenols: A time-dependent density functional theory study

2012 ◽  
Vol 131 (1) ◽  
pp. 79-89 ◽  
Author(s):  
El Hassane Anouar ◽  
Johannes Gierschner ◽  
Jean-Luc Duroux ◽  
Patrick Trouillas
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Time Dependent ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Natural Polyphenols ◽  
Visible Spectra ◽  
Uv Visible ◽  
Dependent Density
Sign in / Sign up

Export Citation Format

Share Document