scholarly journals Synthesis and Spectral Properties of Gem-Dimethyl Chlorin Photosensitizers

2020 ◽  
Author(s):  
zoi melissari ◽  
harry sample ◽  
Brendan Twamley ◽  
René M. Williams ◽  
Mathias Senge
Keyword(s):  
Spectral Properties ◽  
Density Functional ◽  
Antimicrobial Agents ◽  
Photophysical Properties ◽  
Complete Characterization ◽  
Free Base ◽  
Resistance To Oxidation ◽  
Td Dft ◽  
Moderate Yield

Chlorins that bear a gem-dimethyl group, which attributes their resistance to oxidation, are of interest for applications in photomedicine. Herein, we present the synthesis and the photophysical properties of two geminal-dimethyl chlorins (dihydroporphyrins) and their free base counterparts that act as efficient singlet oxygen generators and thus exhibit potential for use in photodynamic therapy (PDT) as anticancer or antimicrobial agents upon further derivatization. A complete characterization of their spectral and photophysical properties is accompanied by density functional calculations (DFT) as well as time dependent (TD) DFT to investigate the features of the frontier molecular orbitals. To demonstrate the potential of these compounds, standard palladium mediated reaction yielded a porphyrin-chlorin dyad in moderate yield.

scholarly journals Synthesis and Spectral Properties of Gem-Dimethyl Chlorin Photosensitizers

2020 ◽  
Author(s):  
zoi melissari ◽  
harry sample ◽  
Brendan Twamley ◽  
René M. Williams ◽  
Mathias Senge
Keyword(s):  
Spectral Properties ◽  
Density Functional ◽  
Antimicrobial Agents ◽  
Photophysical Properties ◽  
Complete Characterization ◽  
Free Base ◽  
Resistance To Oxidation ◽  
Td Dft ◽  
Moderate Yield

Chlorins that bear a gem-dimethyl group, which attributes their resistance to oxidation, are of interest for applications in photomedicine. Herein, we present the synthesis and the photophysical properties of two geminal-dimethyl chlorins (dihydroporphyrins) and their free base counterparts that act as efficient singlet oxygen generators and thus exhibit potential for use in photodynamic therapy (PDT) as anticancer or antimicrobial agents upon further derivatization. A complete characterization of their spectral and photophysical properties is accompanied by density functional calculations (DFT) as well as time dependent (TD) DFT to investigate the features of the frontier molecular orbitals. To demonstrate the potential of these compounds, standard palladium mediated reaction yielded a porphyrin-chlorin dyad in moderate yield.

Photophysical Properties of N-Methyl and N-Acetyl Substituted Alloxazine: A Theoretical Investigation

2021 ◽  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...

scholarly journals Spectral properties of coumarin derivatives in various environments

2013 ◽  
Vol 11 (4) ◽  
pp. 492-501 ◽  
Author(s):  
Alzbeta Holubekova ◽  
Pavel Mach ◽  
Jan Urban
Keyword(s):  
Gas Phase ◽  
Absorption Spectra ◽  
Spectral Properties ◽  
Density Functional ◽  
Water Solution ◽  
Blue Shift ◽  
Coumarin Derivatives ◽  
Complex Environments ◽  
Td Dft ◽  
Solvent Environment

AbstractThe structural and spectral properties of coumarin derivatives in complex environments were investigated within the time-dependent density functional theory (TD DFT). Absorption spectra calculations were obtained at TD PBE0/6-31+G(d,p) level of theory for coumarin47 in the gas-phase and in various polar and non-polar organic solvents. The geometries of coumarins 6, 30, 47 and 522 in the gas phase and in inclusion complexes with the β-cyclodextrin (βCD) were determined by PM3 and DFT (HCTH/6-31G) calculations. Encapsulation of coumarin in βCD and associated changes in electronic structure produced either a red or blue shift in the absorption spectra of coumarins. A proposed cavity model for βCD-coumarin complex in water solution allowed identification of various contributions to the overall shift in the absorption spectra of coumarin upon complex formation in a solvent environment

scholarly journals Excited State Dynamics of 8-Vinyldeoxyguanosine in Aqueous Solution Studied by Time-Resolved Fluorescence Spectroscopy and Quantum Mechanical Calculations

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 824
Author(s):  
Lara Martinez-Fernandez ◽  
Thomas Gustavsson ◽  
Ulf Diederichsen ◽  
Roberto Improta
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Radiative Decay ◽  
Decay Channel ◽  
Photophysical Properties ◽  
Time Resolved ◽  
Td Dft ◽  
Bonding Properties ◽  
Purine Ring ◽  
Vinyl Group

The fluorescent base guanine analog, 8-vinyl-deoxyguanosine (8vdG), is studied in solution using a combination of optical spectroscopies, notably femtosecond fluorescence upconversion and quantum chemical calculations, based on time-dependent density functional theory (TD-DFT) and including solvent effect by using a mixed discrete-continuum model. In all investigated solvents, the fluorescence is very long lived (3–4 ns), emanating from a stable excited state minimum with pronounced intramolecular charge-transfer character. The main non-radiative decay channel features a sizeable energy barrier and it is affected by the polarity and the H-bonding properties of the solvent. Calculations provide a picture of dynamical solvation effects fully consistent with the experimental results and show that the photophysical properties of 8vdG are modulated by the orientation of the vinyl group with respect to the purine ring, which in turn depends on the solvent. These findings may have importance for the understanding of the fluorescence properties of 8vdG when incorporated in a DNA helix.

scholarly journals Ethyne Functionalized Meso-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4546
Author(s):  
Eva Molnar ◽  
Emese Gál ◽  
Luiza Găină ◽  
Castelia Cristea ◽  
Luminița Silaghi-Dumitrescu
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Soret Band ◽  
Quantum Yields ◽  
Free Base ◽  
Wave Absorption ◽  
Long Wave

Synthesis, structural characterization and photophysical properties for a series of new trans-A2B2- and A3B-type ethynyl functionalized meso-phenothiazinyl-phenyl porphyrin derivatives are described. The new compounds displayed the characteristic porphyrin absorption spectra slightly modified by weak auxochromic effects of the substituents and fluorescence emission in the range of 651–659 nm with 11–25% quantum yields. The changes recorded in the UV-vis absorption spectra in the presence of trifluoroacetic acid (TFA) are consistent with the protonation of the two internal nitrogen atoms of the free-base porphyrin (19 nm bathochromic shift of the strong Soret band and one long wave absorption maxima situated in the range of 665–695 nm). Protonation of the phenothiazine substituents required increased amounts of TFA and produced a distinct hypsochromic shift of the long wave absorption maxima. The density functional theory (DFT) calculations of a porphyrin dication pointed out a saddle-distorted porphyrin ring as the ground-state geometry.

scholarly journals Computer aided chemical design: using quantum chemical calculations to predict properties of a series of halochromic guaiazulene derivatives

2016 ◽  
Vol 3 (11) ◽  
pp. 160373 ◽  
Author(s):  
Adam W. Woodward ◽  
Ebrahim H. Ghazvini Zadeh ◽  
Mykhailo V. Bondar ◽  
Kevin D. Belfield
Keyword(s):  
Data Storage ◽  
Density Functional ◽  
Computational Study ◽  
Photophysical Properties ◽  
Photon Absorption ◽  
Optoelectronic System ◽  
Dft Methods ◽  
Two Photon Absorption ◽  
Td Dft ◽  
Calculation Results

With the scientific community becoming increasingly aware of the need for greener products and methodologies, the optimization of synthetic design is of greater importance. Building on experimental data collected from a synthesized guaiazulene derivative, a series of analogous structures were investigated with time-dependent density functional theory (TD-DFT) methods in an effort to identify a compound with desirable photophysical properties. This in silico analysis may eliminate the need to synthesize numerous materials that, when investigated, do not possess viable characteristics. The synthesis of several computationally investigated structures revealed discrepancies in the calculation results. Further refined computational study of the molecules yielded results closer to those observed experimentally and helps set the stage for computationally guided design of organic photonic materials. Three novel derivatives were synthesized from guaiazulene, a naturally occurring chromophore, exhibiting distinct halochromic behaviour, which may have potential in a switchable optoelectronic system or combined with a photoacid generator for data storage. The protonated forms were readily excitable via two-photon absorption.

Investigating the optical properties of BOIMPY dyes using ab initio tools

2017 ◽  
Vol 19 (16) ◽  
pp. 10554-10561 ◽  
Author(s):  
Boris Le Guennic ◽  
Giovanni Scalmani ◽  
Michael J. Frisch ◽  
Adèle D. Laurent ◽  
Denis Jacquemin
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Computational Approach ◽  
Time Dependent ◽  
Coupled Cluster ◽  
Functional Theory ◽  
Td Dft ◽  
Large Panel ◽  
Dependent Density

Using a computational approach combining Time-Dependent Density Functional Theory (TD-DFT) and second-order Coupled Cluster (CC2) approaches, we investigate the spectral properties of a large panel of BOIMPY dyes.

scholarly journals Theoretical modeling of optical spectra of N(1) and N(10) substituted lumichrome derivatives

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Denisa Cagardová ◽  
Jan Truksa ◽  
Martin Michalík ◽  
Jan Richtár ◽  
Jozef Krajčovič ◽  
...  
Keyword(s):  
Density Functional ◽  
Optical Transition ◽  
Photophysical Properties ◽  
Energy Levels ◽  
Dft Method ◽  
Functional Theory ◽  
Transition Energies ◽  
The Density Functional Theory ◽  
Td Dft

AbstractA systematic study of (7,8-dimethylated) alloxazine, isoalloxazine, and their derivatives with substituted N(1) and N(10) positions was conducted using the density functional theory. The main aim of this work was the direct investigation of substituent effect on the molecular structure. Furthermore, HOMED aromaticity indices were calculated to describe the scope of the geometry changes. Frontier molecular orbitals of reference alloxazine, isoalloxazine and lumichrome derivatives were discussed by means of changes in their shape and energy levels. Photophysical properties were analyzed by determination of optical transition energies using the TD-DFT method. Obtained results were compared with previously published experimental data.

scholarly journals Spectral Properties of Highly Emissive Derivative of Coumarin with N,N-Diethylamino, Nitrile and Tiophenecarbonyl Moieties in Water-Methanol Mixture

2019 ◽  
Vol 29 (6) ◽  
pp. 1393-1399
Author(s):  
Anna Kolbus ◽  
Andrzej Danel ◽  
Danuta Grabka ◽  
Mateusz Kucharek ◽  
Karol Szary
Keyword(s):  
Quantum Yield ◽  
Fluorescence Lifetime ◽  
Spectral Properties ◽  
Density Functional ◽  
Photophysical Properties ◽  
Functional Theory ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Methanol Mixture ◽  
Michael Type Addition

AbstractThe new derivative of coumarin (E)-3-[7-(diethyloamino)-2-oxo-chromen-3yl]-2-(tiophene-2-carbonyl)prop-2-enenitrile (NOSQ) was easy synthesized with commercial substrates as a result of the search of new Michael type addition sensors based on coumarins. Spectral properties of highly emissive NOSQ were investigated by steady state analysis (absorption and fluorescence measurements) and time-resolved analysis (fluorescence lifetime measurements). The effect of water-methanol mixture on the photophysical properties of the NOSQ molecule was analyzed. With increasing of volumetric fraction of water the intensity of absorbance and fluorescence was strongly reduced. The NOSQ quantum yield in methanol was quite high and the first portions of water caused a significant increase in this value. Water, which is usually a quencher, in this case caused the increase in the quantum yield. The fluorescence lifetimes had second-order decay and the values of fluorescence lifetime increased with increasing alcohol content. Density functional theory (DFT) calculations and experimental data remained in agreement and showed that the interaction between the NOSQ molecule and the solvent affects the appearance of the new conformer.

scholarly journals A DFT Study of Some Structural and Spectral Properties of 4-Methoxyacetophenone Thiosemicarbazone and Its Complexes with Some Transition Metal Chlorides: Potent Antimicrobial Agents

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Julius Numbonui Ghogomu ◽  
Nyiang Kennet Nkungli
Keyword(s):  
Transition Metal ◽  
Spectral Properties ◽  
Density Functional ◽  
Antimicrobial Agents ◽  
Population Analysis ◽  
Binding Energies ◽  
Rational Drug Design ◽  
Ethanolic Solution ◽  
Metal Chlorides ◽  
Chemical And Biological Systems

Recent studies have shown that 4-methoxyacetophenone thiosemicarbazone (MAPTSC) and its complexes with some transition metal chlorides are potent antimicrobial agents. To deepen the understanding of their structure-activity relationships necessary for rational drug design, their structural and spectral properties, along with thione-thiol tautomerism of MAPTSC, have been studied herein using the density functional theory (DFT). From our results, the thione tautomer of MAPTSC is more stable than the thiol counterpart in ethanolic solution, and thione-to-thiol tautomerization is highly precluded at ambient temperature (25°C) by a high barrier height ≈46.41 kcal/mol. MAPTSC can therefore exist as a mixture of the thione (major) and thiol (minor) tautomers in ethanolic solution at room and higher temperatures. Conformational analysis has revealed five possible conformers of the thione tautomer, of which two are stable enough to be isolated at 25°C. Based on our computed values of MAPTSC-metal(II) binding energies, enthalpies, and Gibbs free energies, the thione tautomer of MAPTSC exhibits a higher affinity for the d8 metal ions Ni(II), Pd(II), and Pt(II) and can therefore efficiently chelate them in chemical and biological systems. Natural population analysis has revealed ligand-metal charge transfer in the MAPTSC complexes studied. A good agreement has been found between calculated and experimentally observed spectral properties (IR, UV-Vis, and NMR).

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