scholarly journals Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

2015 ◽  
Vol 11 ◽  
pp. 1434-1440 ◽  
Author(s):  
Dileep Kumar Singh ◽  
Mahendra Nath
Keyword(s):  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Cycloaddition Reaction ◽  
Spectroscopic Characterization ◽  
Spectroscopic Properties ◽  
Dipolar Cycloaddition ◽  
Free Base ◽  
Acidic Conditions ◽  
Derivatives Of

A novel series of β-triazoloporphyrin–xanthone conjugates and xanthone-bridged β-triazoloporphyrin dyads has been synthesized in moderate to good yields through Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of copper(II) 2-azido-5,10,15,20-tetraphenylporphyrin or zinc(II) 2-azidomethyl-5,10,15,20-tetraphenylporphyrin with various alkyne derivatives of xanthones in DMF containing CuSO4 and ascorbic acid at 80 °C. Furthermore, these metalloporphyrins underwent demetalation under acidic conditions to afford the corresponding free-base porphyrins in good to excellent yields. After successful spectroscopic characterization, these porphyrins have been evaluated for their photophysical properties. The preliminary results revealed a bathochromic shift in the UV–vis and fluorescence spectra of these porphyrin–xanthone dyads.

Spectroscopic characterization of free-base hydroxy(arylethynyl)porphyrins in acidic and basic media

2017 ◽  
Vol 21 (10) ◽  
pp. 680-691
Author(s):  
Kaarin K. Evens ◽  
Kathryn E. Splan
Keyword(s):  
Spectroscopic Characterization ◽  
Spectral Features ◽  
Free Base ◽  
Enhanced Absorption ◽  
Spectral Shifts ◽  
Porphyrin Macrocycle ◽  
Show Evidence ◽  
Acidic Conditions

The addition of arylethynyl groups to the porphyrin macrocycle represents an effective strategy with which to enhance the light-harvesting properties of porphyrins. We now extend this modification to arylethynyl porphyrins with two or four [Formula: see text]-hydroxyphenyl substituents. Arylethynyl porphyrins bearing four, but not two, [Formula: see text]-hydroxyphenyl substituents show evidence of aggregation under acidic conditions. Under basic conditions, deprotonation of the peripheral hydroxyphenyl substituents results in substantially red-shifted spectral features and enhanced absorption in the Q-band region. When the hydroxyphenyl groups are appended to the porphyrin macrocylce via the ethynyl spacers, the spectral shifts observed upon deprotonation are significantly enhanced relative to those observed for hydroxyphenylporphyrins, highlighting the role of expanded conjugation in altering porphyrin photophysics.

scholarly journals Synthesis, photophysical properties and photodynamic antimicrobial activity of meso 5,10,15,20-tetra(pyren-1-yl)porphyrin and its indium(III) complex

2021 ◽  
pp. A-F
Author(s):  
Jackline Khisa ◽  
Solomon Derese ◽  
John Mack ◽  
Edith Amuhaya ◽  
Tebello Nyokong
Keyword(s):  
Mass Spectrometry ◽  
Antimicrobial Activity ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Intersystem Crossing ◽  
Free Base ◽  
H Nmr ◽  
Solvent Systems ◽  
Dose Dependent

In this study, free-base meso 5,10,15,20-tetra(pyren-1-yl)porphyrin (H2TPyP) and its corresponding indium(III) complex (InClTPyP) were synthesized and characterized on the basis of mass spectrometry, 1H NMR spectroscopy and elemental analysis. InClTPyP was obtained in good yield by treating the free base H2TPyP with indium(III) chloride. Purification of these compounds was achieved through column chromatography using different solvent systems. Metallation of the free base to form a metallo-porphyrin afforded improved photophysical properties. There was a bathochromic shift in wavelength of absorption from the parent free base H2TPyP ([Formula: see text] = 431 nm) to metallated indium(III) complex ([Formula: see text] = 443 nm). The fluorescence quantum yield in H2TPyP was higher ([Formula: see text] = 0.131) than in InClTPyP ([Formula: see text] = 0.017) due to efficient intersystem crossing to the triplet manifold in the metallated porphyrin. Upon illumination, both H2TPyP and InClTPyP show effective dose dependent antimicrobial activity against Staphylococcus aureus with photoinactivation IC[Formula: see text] values of 27.89 and 16.67 [Formula: see text]M, respectively.

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.

Synthesis and Spectroscopic Properties of a Novel Bifunctional Pyrene Derivative and its Incorporation into OligoDNA

2015 ◽  
Vol 68 (2) ◽  
pp. 256 ◽  
Author(s):  
Tomohisa Moriguchi ◽  
Satomi Hida ◽  
Fumio Yoneda ◽  
Kazuo Shinozuka
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Spectra ◽  
Bathochromic Shift ◽  
Spectroscopic Properties ◽  
Absorption And Fluorescence Spectra ◽  
Electron Withdrawing Group

A new pyrene derivative bearing a modifiable silyl function (electron-donating group) and cyano function (electron-withdrawing group) was synthesized as a labelling agent for biological substances. The modified pyrene exhibited a marked bathochromic shift in both absorption and fluorescence spectra. The fluorescence quantum yield of the modified pyrene was also significantly increased compared with that of the unmodified pyrene. The modified pyrene was successfully incorporated into oligoDNA.

scholarly journals Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3387
Author(s):  
Agnieszka Skotnicka ◽  
Przemysław Czeleń
Keyword(s):  
Spectral Properties ◽  
Nmr Spectra ◽  
Fluorescent Dyes ◽  
Photophysical Properties ◽  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Azo Group ◽  
Group Rotation ◽  
Derivatives Of ◽  
Substituted 1

Novel fluorescent dyes such as difluoroborane complexes of 1-phenylazonaphthalen-2-ol derivatives were successfully synthesized and characterized with a focus on the influence of a substituent and a solvent on the basic photophysical properties. 1H, 11B, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of substituted 1-phenylazonaphthalen-2-ol difluoroboranes and their parent azo dyes were recorded and discussed. The absorption and emission properties of synthesized compounds were investigated in solvents of varying polarity. They were found to be fluorescent despite the presence of the azo group. The azo group rotation was blocked by complexing with -BF2 to get a red shift in absorption. Solvent-dependent spectral properties of compounds were investigated using Lipper-Mataga and Bakhshiev plot. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations.

scholarly journals Solvatochromic Study of Supramolecular Amphiphile Based on Calix[4]arene Connected to a Fluorescent Benzofurazan Moiety at Lower Rim: Evaluation of Ground and Excited State Dipole Moments-=SUP=-*-=/SUP=-

2020 ◽  
Vol 128 (12) ◽  
pp. 1864
Author(s):  
S. Joshi
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Ground State ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Wide Range ◽  
Excited State Dipole Moment

Photophysical properties of a supramolecular amphiphile of calix[4]arene having benzofurazan moiety at the lower rim, L has been studied. Electronic absorption and fluorescence spectra of L have been recorded in wide range of solvents of different polarities and data were used to study solvatochromic properties. The ground state and the excited state dipole moment of L were estimated from the Bakhshiev's and Bilot-Kawaski's equations. High value of dipole moment is observed for excited state as compared to ground state value and this is attributed to more polar excited state of molecule. Also, fluorescence emission peak undergoes a bathochromic shift with increase in the polarity of the solvent, confirming π-> π* transition. Scanning electron microscopy reveals that the aggregation of L is increased on going from the polar to non polar solvents. Keywords: solvatochromism, benzofurazan, dipole moment, quantum yield, absorption, fluoresence.

Sign in / Sign up

Export Citation Format

Share Document