Photoacoustic measurement of photophysical properties. Lowest triple-state energy of a free base porphyrin

1982 ◽  
Vol 104 (25) ◽  
pp. 7356-7357 ◽  
Author(s):  
Thomas A. Moore ◽  
David Benin ◽  
Roderick Tom
Keyword(s):  
State Energy ◽  
Photophysical Properties ◽  
Free Base ◽  
Photoacoustic Measurement

Photophysical Properties of β-Substituted Free-Base Corroles

2015 ◽  
Vol 54 (6) ◽  
pp. 2713-2725 ◽  
Author(s):  
Christopher M. Lemon ◽  
Robert L. Halbach ◽  
Michael Huynh ◽  
Daniel G. Nocera
Keyword(s):  
Photophysical Properties ◽  
Free Base

Synthesis and Photophysical Properties of a Conformationally Flexible Mixed Porphyrin Star-Pentamer

2009 ◽  
Vol 62 (7) ◽  
pp. 692 ◽  
Author(s):  
Toby D. M. Bell ◽  
Sheshanath V. Bhosale ◽  
Kenneth P. Ghiggino ◽  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Fluorescence Decay ◽  
High Yield ◽  
Free Base ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Relative Contribution ◽  
Synthetic Strategy ◽  
Decay Times

The synthesis of a porphyrin star-pentamer bearing a free-base porphyrin core and four zinc(ii) metalloporphyrins, which are tethered by a conformationally flexible linker about the central porphyrin’s antipody, is described. The synthetic strategy is highlighted by the use of olefin cross metathesis to link the five chromophores together in a directed fashion in high yield. Photoexcitation into the Soret absorption band of the zinc porphyrin chromophores at 425 nm leads to a substantial enhancement of central free-base porphyrin fluorescence, indicating energy transfer from the photoexcited zinc porphyrin (outer periphery) to central free-base porphyrin. Time-resolved fluorescence decay profiles required three exponential decay components for satisfactory fitting. These are attributed to emission from the central free-base porphyrin and to two different rates of energy transfer from the zinc porphyrins to the free-base porphyrin. The faster of these decay components equates to an energy-transfer rate constant of 3.7 × 109 s–1 and an efficiency of 83%, whereas the other is essentially unquenched with respect to reported values for zinc porphyrin fluorescence decay times. The relative contribution of these two components to the initial fluorescence decay is ~3:2, similar to the 5:4 ratio of cis and trans geometric isomers present in the pentamer.

Polypeptides with pendant porphyrins of defined sequence of chromophores: towards artificial photosynthetic systems

2008 ◽  
Vol 12 (12) ◽  
pp. 1232-1241 ◽  
Author(s):  
Farid Aziat ◽  
Régis Rein ◽  
Jorge Peón ◽  
Ernesto Rivera ◽  
Nathalie Solladié
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Amino Acid ◽  
Fluorescence Spectroscopy ◽  
Photophysical Properties ◽  
Free Base ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Absorption And Fluorescence Spectroscopy ◽  
Artificial Photosynthetic

In this paper we now report our ongoing progress in the preparation of artificial photosynthetic systems through the preparation of light harvesting multi-porphyrins. A tetramer, constituted of a central dipeptide functionalized by two free-base porphyrins and surrounded by one amino-acid bearing a pendant Zn ( II ) porphyrin on each side, has been chosen. The optical and photophysical properties of this tetramer have been studied by absorption and fluorescence spectroscopy. In addition, the energy transfer phenomenon has been studied and monitored by femtosecond time-resolved fluorescence. Our results indicate that the excited state dynamics redounding in the excitation being localized in the inner free-base porphyrins takes place in the time scale of approximately 1 ps.

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.

Comparative Photophysical Properties of Free-Base, Bis-Zn(II), Bis-Cu(II), and Bis-Co(II) Doubly N-Confused Hexaphyrins(1.1.1.1.1.1)

2006 ◽  
Vol 110 (24) ◽  
pp. 11683-11690 ◽  
Author(s):  
Jung Ho Kwon ◽  
Tae Kyu Ahn ◽  
Min-Chul Yoon ◽  
Deok Yun Kim ◽  
Mi Kyoung Koh ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Free Base

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.

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