Solvent Effects on the Valence UV−Vis Absorption Spectra of Topotecan Anticancer Drug in Aqueous Solution at Room Temperature: A Nanoseconds Time-Scale TD-DFT/MD Computational Study

2010 ◽  
Vol 114 (20) ◽  
pp. 6770-6778 ◽  
Author(s):  
Costantino Zazza ◽  
Andrea Coletta ◽  
Nico Sanna ◽  
Giovanni Chillemi ◽  
Giordano Mancini ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectra ◽  
Anticancer Drug ◽  
Solvent Effects ◽  
Time Scale ◽  
Room Temperature ◽  
Computational Study ◽  
Td Dft

scholarly journals Simulating Absorption Spectra of Flavonoids in Aqueous Solution: A Polarizable QM/MM Study

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5853
Author(s):  
Sulejman Skoko ◽  
Matteo Ambrosetti ◽  
Tommaso Giovannini ◽  
Chiara Cappelli
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Force Field ◽  
Absorption Spectra ◽  
Computational Study ◽  
Md Simulations ◽  
Quantum Mechanical ◽  
Hydrogen Bonding Interactions

We present a detailed computational study of the UV/Vis spectra of four relevant flavonoids in aqueous solution, namely luteolin, kaempferol, quercetin, and myricetin. The absorption spectra are simulated by exploiting a fully polarizable quantum mechanical (QM)/molecular mechanics (MM) model, based on the fluctuating charge (FQ) force field. Such a model is coupled with configurational sampling obtained by performing classical molecular dynamics (MD) simulations. The calculated QM/FQ spectra are compared with the experiments. We show that an accurate reproduction of the UV/Vis spectra of the selected flavonoids can be obtained by appropriately taking into account the role of configurational sampling, polarization, and hydrogen bonding interactions.

Experimental and computational study of solvent effects on one- and two-photon absorption spectra of chlorinated harmines

2015 ◽  
Vol 17 (18) ◽  
pp. 12090-12099 ◽  
Author(s):  
Dalibor Hršak ◽  
Lotte Holmegaard ◽  
Anton S. Poulsen ◽  
Nanna H. List ◽  
Jacob Kongsted ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Solvent Effects ◽  
Computational Study ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Acetonitrile Solutions

We present a combined experimental and computational study of one- and two-photon absorption spectra of protonated chloroharmines in aqueous and acetonitrile solutions.

Benchmarking TD-DFT against Vibrationally Resolved Absorption Spectra at Room Temperature: 7-Aminocoumarins as Test Cases

2015 ◽  
Vol 11 (11) ◽  
pp. 5371-5384 ◽  
Author(s):  
Francesco Muniz-Miranda ◽  
Alfonso Pedone ◽  
Giulia Battistelli ◽  
Marco Montalti ◽  
Julien Bloino ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Room Temperature ◽  
Test Cases ◽  
Td Dft

Computational study on zinc porphyrin analogs for use in dye-sensitized solar cells

2014 ◽  
Vol 18 (05) ◽  
pp. 406-415 ◽  
Author(s):  
Hong-Qiang Xia ◽  
Jie Chen ◽  
Fu-Quan Bai ◽  
Hong-Xing Zhang
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Computational Study ◽  
Dye Sensitized Solar Cells ◽  
Absorption Enhancement ◽  
Zinc Porphyrin ◽  
The Density Functional Theory ◽  
Td Dft ◽  
Sensitized Solar Cells ◽  
Porphyrin Analogs

The density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches have been applied to obtain the optimized geometries, electronic structures, molecular orbitals and absorption spectra of a series of meso-substituted zinc porphyrin analogs with phenyl and thiophene groups as the π bridging unit and cyanoacrylic acid as the acceptor unit. The results showed that the introduction of thiophene group increases the orbital splitting and changes the absorption spectra properties significantly. It is indicated that when there is only one thiophene group included in the π bridge, the oscillator strength of B absorption band is much stronger. The increasing length of thiophene chain just changes the scope of specific absorption enhancement. The effect of attaching an additional electron-donating group diphenylamine instead of phenyl to the porphyrin core also has been shown. It is found that the diphenylamine group reduces the band gap, and leads to facile intramolecular charge transfer from diphenylamine and porphyrin ring unit to acceptor unit. These kinds of zinc porphyrin analogs have the LUMO energy close to the conduction band of TiO 2 and more red-shifted absorption spectrum compared with phenyl substituted analogs.

scholarly journals Computational Study on the Mechanism of the Photouncaging Reaction of Vemurafenib: Toward an Enhanced Photoprotection Approach for Photosensitive Drugs

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1846
Author(s):  
Abdulilah Dawoud Bani-Yaseen
Keyword(s):  
Anticancer Drug ◽  
Density Functional ◽  
Computational Study ◽  
Intramolecular Proton Transfer ◽  
Substantial Impact ◽  
Photochemical Behavior ◽  
Td Dft ◽  
Notable Increase ◽  
The Impact ◽  
Kinetics Of

The photochemical behavior of the photosensitive first-line anticancer drug vemurafenib (VFB) is of great interest due to the impact of such behavior on its pharmacological activity. In this work, we computationally elucidated the mechanism of the photoinduced release of VFB from the 4,5-dimethoxy-2-nitrobenzene (DMNB) photoprotecting group by employing various density functional theory (DFT)/time-dependent DFT (TD-DFT) approaches. The computational investigations included a comparative assessment of the influence of the position of the photoprotecting group as a substituent on the thermodynamics and kinetics of the photouncaging reactions of two VFB-DMNB prodrugs, namely pyrrole (NP) and sulfonamide (NS). With the aid of the DFT calculations concerning the activation energy barrier (∆G‡), the obtained results suggest that the step of the photoinduced intramolecular proton transfer of the DMNB moiety is not detrimental concerning the overall reaction profile of the photouncaging reaction of both prodrugs. However, the obtained results suggested that the position of the substitution position of the DMNB photoprotecting group within the prodrug structure has a substantial impact on the photouncaging reaction. In particular, the DMNB-Ns-VFB prodrug exhibited a notable increase in ∆G‡ for the key step of ring opining within the DMNB moiety indicative of potentially hindered kinetics of the photouncaging process compared with DMNB-Np-VFB. Such an increase in ∆G‡ may be attributed to the electronic influence of the NP fragment of the prodrug. The results reported herein elaborate on the mechanism of the photoinduced release of an important anticancer drug from photoprotecting groups with the aim of enhancing our understanding of the photochemical behavior of such photosensitive pharmaceutical materials at the molecular level.

Absorption spectra of xanthines in aqueous solution: a computational study

2020 ◽  
Vol 22 (10) ◽  
pp. 5929-5941 ◽  
Author(s):  
Sara Gómez ◽  
Tommaso Giovannini ◽  
Chiara Cappelli
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectra ◽  
Computational Analysis ◽  
Computational Study

We present a detailed computational analysis of the UV/Vis spectra of caffeine, paraxanthine and theophylline in aqueous solution.

Interplay between conformational and solvent effects in UV-visible absorption spectra: curcumin tautomers as a case study

2019 ◽  
Vol 21 (28) ◽  
pp. 15504-15514 ◽  
Author(s):  
Alessandra Puglisi ◽  
Tommaso Giovannini ◽  
Liudmil Antonov ◽  
Chiara Cappelli
Keyword(s):  
Aqueous Solution ◽  
Experimental Study ◽  
Absorption Spectra ◽  
Solvent Effects ◽  
Visible Absorption ◽  
Tautomeric Forms ◽  
Uv Visible

We present a combined theoretical and experimental study on the UV-vis spectra of enol–keto (EK) and keto–keto (KK) tautomeric forms of curcumin dissolved in aqueous solution.

scholarly journals Density Functional Theory Study of the Solvent Effects on Electronic Transition Energies of Porphyrins

2021 ◽  
Author(s):  
Metin Aydin
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Solvent Effects ◽  
Density Functional ◽  
Dielectric Constants ◽  
Triplet States ◽  
Spectral Position ◽  
Functional Theory ◽  
Td Dft ◽  
Electronic Transition Energies

We have calculated the solvent effects on the ground state and the lowest triplet state absorption spectra of meso-tetraphenylporphyrin (TPP), meso-tetrakis(p-sulfonatophenyl)porphyrin (TSPP) and their diprotonated forms (H4TPP and H4TSPP) in thirty-nine different solvent using time-dependent-DFT density functional theory (TD-DFT) coupled with CPCM method. The results of the calculations show that the Q-bands and Soret-bands (or B-bands) in the absorption spectra of these compounds substantially change as function of solvent dielectric constant (ε) up to 20.493 (acetone), but become stabile in high polar solvents with dielectric constants ε > 20. The relative shifts in the B-bands are more significant than that in the Q-bands. The magnitude of the shifts in the spectral position of the Q and B bands are in the following order: H4TSPP > H4TPP > TPP > TSPP for the B-bands and H4TSPP > H4TPP > TSPP > TPP for the Q-bands. We also have determined that the energy-gaps between the B/Q-bands and their nearest triplet states are also solvent dependent for ε < ~ 20.493.

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