scholarly journals TD-DFT/DFT study of Toluidine blue O in aqueous solution: vibronic transitions and electronic properties

2021 ◽  
Author(s):  
Lyudmila Kostjukova ◽  
Svetlana Leontieva ◽  
Victor Kostjukov
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Toluidine Blue ◽  
Density Functional ◽  
Dipole Moments ◽  
Basis Set ◽  
Functional Theory ◽  
Solvent Models ◽  
Td Dft ◽  
Vibronic Transitions

The vibronic absorption spectrum of Toluidine blue O (TBO) dye in an aqueous solution was calculated using the time-dependent density functional theory (TD-DFT). The calculations were performed using all hybrid functionals supported by Gaussian16 software and 6-31++G(d,p) basis set with IEFPCM and SMD solvent models. The IEFPCM gave underestimated values of λmax in comparison with the experiment, what is a manifestation of the TD-DFT “cyanine failure”. However, the SMD made it possible to obtain good agreement between calculated and experimental spectra. The best fit was achieved using the X3LYP functional. The dipole moments and atomic charges of the ground and excited states of the TBO molecule were calculated. Photoexcitation leads to an increase in the dipole moment of the dye molecule. An insignificant photoinduced electron transfer was found in the central ring of the chromophore of the TBO molecule. Vibronic transitions play a significant role in the absorption spectrum of the dye.

scholarly journals Modeling the absorption spectrum of the permanganate ion in vacuum and in aqueous solution

2017 ◽  
Vol 19 (24) ◽  
pp. 15870-15875 ◽  
Author(s):  
Jógvan Magnus Haugaard Olsen ◽  
Erik Donovan Hedegård
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Complete Active Space ◽  
Water Solvent ◽  
Solvent Models ◽  
Solvent Shift ◽  
Range Density

The absorption spectrum of MnO4− in vacuum and aqueous solution is modeled using the range-separated complete active space short-range density functional theory method (CAS-srDFT) combined with either implicit (PCM) or explicit (PE) solvent models. The experimental vacuum-to-water solvent shift of the lowest intense transition is reproduced by PE-CAS-srDFT.

Donor Functionalized Perylene and Different π-Spacers Based Sensitizers for DSSC Applications - A Theoretical Approach

2021 ◽  
Author(s):  
D. Nicksonsebastin ◽  
P. Pounraj ◽  
Prasath M
Keyword(s):  
Density Functional Theory ◽  
Solar Cell ◽  
Gas Phase ◽  
Density Functional ◽  
Basis Set ◽  
Dye Sensitized Solar Cell ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Organic Sensitizers

Abstract Perylene based novel organic sensitizers for the Dye sensitized solar cell applications are investigated by using Density functional theory (DFT) and time dependant density functional theory (TD-DFT).The designed sensitizers have perylene and dimethylamine (DM) and N-N-dimethylaniline(DMA) functionalized perylene for the dssc applications.π-spacers are thiophene andcyanovinyl groups and cyanoacrylic acid is chosen as the acceptor for the designed sensitizers. The studied sensitizers were fully optimized by density functional theory at B3LYP/6-311G basis set on gas phase and DMF phase. The electronic absorption of the sensitizers is analyzed by TD-DFT at B3LYP/6-311G basis set in both gas and DMF phase.

scholarly journals 1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
Dawid Zych
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Basis Set ◽  
Functional Theory ◽  
Td Dft ◽  
Pyrene Derivatives ◽  
Osmium Complexes ◽  
The Subject ◽  
Theoretical Considerations

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established.

scholarly journals DFT and TD-DFT Study of Structure and Properties of Semiconductive Hybrid Networks Formed by Bismuth Halides and Different Polycyclic Aromatic Ligands

2011 ◽  
Vol 8 (s1) ◽  
pp. S195-S202
Author(s):  
Y. Belhocine ◽  
M. Bencharif
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Relativistic Effects ◽  
Spectroscopic Properties ◽  
Basis Set ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
Polycyclic Aromatic

The structure and spectroscopic properties of polycyclic aromatic ligands of 2,3,6,7,10,11-hexakis (alkylthio) triphenylene (alkyl: methyl, ethyl, and isopropyl; corresponding to the abbreviations of the molecules: HMTT, HETT and HiPTT) were studied using density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods with triple-zeta valence polarization (TZVP) basis set. It was shown that the type of functional theory used, Becke-Perdew (BP) and Leeuwen-Baerends (LB94) implemented in Amsterdam Density functional (ADF) program package, does not have essential influence on the geometry of studied compounds in both ground and excited states. However, significant differences were obtained for the band gap values with relativistic effects of the zero order regular approximation scalar corrections (ZORA) and LB94 functional seems to reproduce better the experimental optical band gap of these systems.

Vibronic absorption spectra and excited states of acridine red dye in aqueous solution: TD-DFT/DFT study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Victor V. Kostjukov
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Hydrogen Bonds ◽  
Absorption Spectra ◽  
Excited States ◽  
Dipole Moments ◽  
Basis Set ◽  
Calculated Spectrum ◽  
Solvent Model ◽  
Acridine Red

Abstract The vibronic absorption spectra of acridine red (AR) xanthene dye in an aqueous solution using 40 hybrid functionals, the 6-31++G(d,p) basis set, and the IEFPCM solvent model were calculated. It turned out that the O3LYP functional provided the best agreement with the experiment in the positions of the main maximum and the short-wavelength subband (shoulder). The calculations showed that this shoulder is vibronic. At the same time, the shoulder intensity in the calculated spectrum turned out to be lower than in the experimental one. Apparently, insignificant dimerization, which occurs even at low concentrations of the dye in solution, contributes to the shoulder of the experimental absorption spectrum. Various parameters of the AR cation in the ground and excited states (IR spectra, atomic charges, dipole moments, and transition moment) were calculated. Maps of the distribution of electron density and electrostatic potential have been built. The influence of the strong hydrogen bonds of the dye with three water molecules on the absorption spectrum was analyzed. It has been shown that these bonds are strengthened upon AR excitation. The strengthening of two hydrogen bonds with water upon excitation leads to a lowering of the potential energy surface of the excited state, which causes a decrease in the excitation energy (i.e., an increase in the wavelength of the absorbed photon) as compared to a purely implicit specification of the water environment. Therefore, explicit assignment of waters strongly bound to the dye leads to spectrum redshift.

Study on the Second-Order Nonlinear Optical Properties of [6]Helicenes with Chromophores

2013 ◽  
Vol 303-306 ◽  
pp. 2563-2566
Author(s):  
Xin Wei Zhang ◽  
Cun Li ◽  
Jun Qi Xu
Keyword(s):  
Density Functional Theory ◽  
Optical Materials ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Molecular Engineering ◽  
Basis Set ◽  
Molecular Configuration ◽  
Functional Theory ◽  
B3lyp Method ◽  
Td Dft

A series of chiral [6]helicenes have been designed using the molecular engineering of organic nonlinear optical materials. The geometries of [6]helicenes 1, 2, 3, 4,5 are optimized using density functional theory (DFT-B3LYP) method at the 6-31g (d, p) basis set level. Based on the obtained stable molecular configuration, we adopt the TDHT/PM3 method and time-dependent density-functional theory (TD-DFT) to calculate the nonlinear optical (NLO) properties and electronic spectra of these molecules. Results show that the static hyperpolarizability βµ alternates between positive value and negative value, whereas it remains positive for the molecues 2 and 3 which have medium magnitudes βµ, 3.4×10-30esu and 9.6×10-30esu respectively. In molecule 5, there exists two competitive charge transfers that reduce the hyperpolarizability β.

Conformational, vibrational and electronic properties of CH3(CH2)3CX2NH2 (X = H, F, Cl or Br): Halogen and solvent effects

2015 ◽  
Vol 14 (04) ◽  
pp. 1550031
Author(s):  
Cemal Parlak ◽  
Münevver Gökce ◽  
Mahir Tursun ◽  
Lydia Rhyman ◽  
Ponnadurai Ramasami
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Basis Set ◽  
Chemical Hardness ◽  
Uv Spectrum ◽  
Dft Methods ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Td Dft

The effects of varying halogen and solvent, in terms of vibrational and electronic properties, on the different conformers of 1-pentanamine [ CH 3( CH 2)4 NH 2] and 1,1-dihalogeno-pentan-1-amines [ CH 3( CH 2)3 CX 2 NH 2; X = F , Cl or Br ] were investigated by employing the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. The B3LYP functional was used with the 6-31++G(d,p) basis set. Computations were focused on the 10 conformational isomers of the compounds in the gas phase and both in non-polar (benzene) and polar (methanol) solvents. The present work explores the effects of the halogen and the medium on the conformational preference, and geometrical parameter, dipole moment, NH 2 vibrational frequency, UV spectrum, highest occupied and lowest unoccupied molecular orbitals (HOMO–LUMO) orbital and DOS diagram of the conformers. The atypical characteristics of fluorine and bromine affecting the electrical bandgap, chemical hardness, electronegativity, PDOS or OPDOS plots and the absorption band are observed correspondingly. The findings of this work can be useful to those systems involving changes in the conformations analogous to the compounds studied.

scholarly journals Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF3OSO3 Radical

2010 ◽  
Vol 65 (8-9) ◽  
pp. 720-724 ◽  
Author(s):  
Carlos J. Cobos ◽  
Adela E. Croce
Keyword(s):  
Absorption Spectrum ◽  
Density Functional ◽  
Basis Set ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Functional Theory ◽  
Dissociation Enthalpy ◽  
The Density Functional Theory ◽  
Uv Visible ◽  
Experimental Absorption

The UV-visible absorption spectrum of the recently reported CF3OSO3 radical has been studied by using the time-dependent generalization of the density functional theory (TDDFT). For this a set of eleven hybrid functionals combined with the 6-311+G(3df) basis set were employed. The main features of the three experimental absorption bands of CF3OSO3 recorded over the 220 - 530 nm range are well reproduced by the calculations. A dissociation enthalpy for the CF3O-SO3 bond of 19.1 kcal mol−1 is predicted at the BAC-G3MP2//B3LYP/6-311+G(3df) level of theory

scholarly journals DFT and TD-DFT Study of Only First Diaminomalenonitrile Based Molecular Receptor for Fluoride Anion: Correlation of Calculated and Experimental Results

2021 ◽  
Vol 13 (3) ◽  
pp. 923-933
Author(s):  
M. A. Kaloo ◽  
H. Bashir ◽  
M. A. Rather ◽  
S. A. Majid ◽  
B. A. Bhat
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Atomic Orbital ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Fluoride Anion ◽  
Functional Theory ◽  
Sensing Mechanism ◽  
Td Dft

In this work, the sensing mechanism of a novel anion receptor, 2-amino-((E)-(4-cyanobenzalidine) amino) maleonitrile reported by Sankar et al. (Analyst 138:4760-4763, 2013) was investigated theoretically with the help of density functional theory (DFT) and time-dependent density functional theory (TD-DFT). From the frontier molecular orbital analysis, it is reasonable to support the proposed charge transfer (ICT) enhancement in the receptor molecule in the presence of F−. A significant reduction in the energy gap (ΔE) from 4.014 eV to 2.342eV between highest occupied and lowest unoccupied energy levels was revealed, leading to the strong redshift of its absorption characteristics. Moreover, 1H NMR was also calculated to further understand the mechanistic insights by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G (d,p) basis set. The spectra were simulated, and the chemical shifts linked to TMS were compared with experimental. Besides, Intrinsic Reaction Coordinates (IRC) were also calculated to understand the sensing mechanism.

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