Photophysical Studies of Porphyrins and Metalloporphyrins:  Accurate Measurements of Fluorescence Spectra and Fluorescence Quantum Yields for Soret Band Excitation of Zinc Tetraphenylporphyrin

2004 ◽  
Vol 108 (21) ◽  
pp. 4570-4575 ◽  
Author(s):  
Jerzy Karolczak ◽  
Dorota Kowalska ◽  
Adam Lukaszewicz ◽  
Andrzej Maciejewski ◽  
Ronald P. Steer
Keyword(s):  
Fluorescence Spectra ◽  
Soret Band ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Photophysical Studies

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

scholarly journals A Singlet Oxygen Photogeneration and Luminescence Study of Unsymmetrically Substituted Mesoporphyrinic Compounds

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Anabela Sousa Oliveira ◽  
Dumitru Licsandru ◽  
Rica Boscencu ◽  
Radu Socoteanu ◽  
Veronica Nacea ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Quantum Yields ◽  
Mean Values ◽  
Oxygen Generation ◽  
Fluorescence Quantum Yields ◽  
Thermally Activated ◽  
Phosphorescence Emission ◽  
Photophysical Studies

This paper deals with a series of new unsymmetrically substituted mesoporphyrins: 5-(2-hydroxyphenyl)-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHO), 5-(3-hydroxyphenyl)-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHM), 5-(4-hydroxyphenyl)-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHP), 5-(2-hydroxyphenyl)-10,15,20-tris-butyl-21,23-H-porphyrin (TBPOHO), and their parent nonsubstituted compounds, respectively, 5,10,15,20-tetrakis-phenyl-21,23-H-porphyrin (TPP) and 5,10,15,20-tetrakis-butyl-21,23-H-porphyrin (TBP). Several photophysical studies were carried out to access the influence of the unsymmetrical substitution at the porphyrinic macrocycle on porthyrin's photophysical properties, especially porthyrin's efficiency as singlet oxygen sensitizers. The quantum yields of singlet oxygen generation were determined in benzene (ΦΔ(TPP) = 0.66 ± 0.05;ΦΔ(TPPOHO) = 0.69 ± 0.04;ΦΔ(TPPOHM) = 0.62 ± 0.04;ΦΔ(TPPOHP) = 0.73 ± 0.03;ΦΔ(TBP) = 0.76 ± 0.03;ΦΔ(TBPOHO) = 0.73 ± 0.02) using the 5,10,15,20-tetraphenyl-21,23-H-porphine (ΦΔ(TPP) = 0.66) and Phenazine (ΦΔ(Phz) = 0.83) as reference compounds. Their fluorescence quantum yields were found to be (Φf(TPPOHO) = 0.10 ± 0.04;Φf(TPPOHM) = 0.09 ± 0.03;Φf(TPPOHP) = 0.13 ± 0.02;Φf(TBP) = 0.08 ± 0.03 andΦf(TBPOHO) = 0.08 ± 0.02 using 5,10,15,20-tetraphenyl-21,23-H-porphine as referenceΦf(TPP) = 0.13). Singlet state lifetimes were also determined in the same solvent. All the porphyrins presented very similar fluorescence lifetimes (mean values ofτS(withO2, air equilibrated) = 9.6 ± 0.3 nanoseconds and (withoutO2, argon purged) = 10.1 ± 0.6 nanoseconds, resp.). The phosphorescence emission was found to be negligible for this series of unsymmetrically substituted mesoporphyrins, but an E-type, thermally activated, delayed fluorescence process was proved to occur at room temperature.

Synthesis, characterization and fluorescence properties study of meso-tetrakis(1-arylpyrazole-4-yl)porphyrins

2005 ◽  
Vol 09 (06) ◽  
pp. 430-435 ◽  
Author(s):  
Can-Cheng Guo ◽  
Tie-Gang Ren ◽  
Jian Wang ◽  
Chun-Yan Li ◽  
Jian-Xin Song
Keyword(s):  
Elemental Analysis ◽  
Mass Spectra ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Red Shift ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
H Nmr ◽  
Reaction Condition

Five new meso-tetrakis(1-arylpyrazol-4-yl)porphyrins were synthesized to investigate their fluorescence properties. Preparation of these porphyrins was carried out by cyclization of tetramethoxypropane with substituted phenylhydrazine, followed by formylation to give the corresponding aldehydes, which reacted with pyrrole under the Adler reaction condition to get the target porphyrins (1a-1e). All the porphyrins were characterized by 1 H NMR, elemental analysis, UV-vis spectra and mass spectra. Red fluorescence emission of these porphyrins was observed in fluorescence spectra. Compared with meso-tetraphenylporphyrin (TPPH2), these meso-tetrakis(1-arylpyrazol-4-yl) porphyrins had a significant red shift in UV-vis and fluorescence spectra with increased fluorescence quantum yields.

Monoterpene-based metallophthalocyanines: Sustainable synthetic approaches and photophysical studies

2020 ◽  
Vol 24 (05n07) ◽  
pp. 947-958
Author(s):  
Andreia C. S. Gonzalez ◽  
Liliana Damas ◽  
Rafael T. Aroso ◽  
Vanessa A. Tomé ◽  
Lucas D. Dias ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Quantum Yields ◽  
Microwave Assisted Synthesis ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Fluorescence Quantum Yields ◽  
Photophysical Studies ◽  
Synthetic Approaches

Tetra-substituted zinc(II) and copper(II) phthalocyanines bearing peripheral alkoxy-monoterpene groups were prepared by conventional vs. non-conventional synthetic approaches (ultrasound and microwave irradiation). The synthesis of (1[Formula: see text]-(–)-myrtenol (a) and (1[Formula: see text],2[Formula: see text],5[Formula: see text]-([Formula: see text]-menthol (b) derived phthalonitrile precursors was performed through ipso-nitro aromatic substitution reactions, with optimal conditions being obtained using ultrasound irradiation, which allowed us to achieve full conversions in 4.5 h, with isolated yields up to 74%. The subsequent cyclotetramerization of monoterpene-based phthalonitriles was carried out using Zn(II) or Cu(II) salts as metal templates, and also using conventional and non-conventional heating methods. Microwave-assisted synthesis was shown to be the most efficient approach, providing complete conversions in 1 h, yielding the target monoterpene-based metallophthalocyanines in up to 70% isolated yields. Furthermore, photophysical and photochemical studies revealed that Zn(II) phthalocyanines possess fluorescence quantum yields in the range of [Formula: see text] 0.27–0.29, while Cu(II) phthalocyanines exhibited room temperature phosphorescence. In addition, the monoterpene-based Zn(II) phthalocyanines led to high singlet oxygen quantum yields ([Formula: see text] 0.55–0.69).

Spontaneous and stimulated emission from dyes. Spectroscopy of the neutral molecules of acridine orange, proflavine, and rhodamine B

1973 ◽  
Vol 26 (8) ◽  
pp. 1617 ◽  
Author(s):  
J Ferguson ◽  
AWH Mau
Keyword(s):  
Acridine Orange ◽  
Rhodamine B ◽  
Fluorescence Spectra ◽  
Laser Emission ◽  
Stimulated Emission ◽  
Quantum Yields ◽  
Polar Solvents ◽  
Laser Efficiency ◽  
Fluorescence Quantum Yields ◽  
Acridine Dyes

The absorption and fluorescence spectra of acridine orange, proflavine, and rhodamine B have been studied with particular attention being paid to the acid-base properties of these dyes in polar and non-polar solvents. These studies show that the neutral acridine dyes do not form dimers but they are readily protonated even in non-polar solvents due to traces of water which are difficult to remove. Attempts to achieve laser emission form the acridine dyes were unsuccessful, probably because of their low fluorescence quantum yields. Suggestions are made for optimizing the laser efficiency of rhodamine B in various alcohol solutions at low temperatures.

scholarly journals Fluorescence properties of halogenated mono-hydroxyl corroles: the heavy-atom effects

2009 ◽  
Vol 13 (12) ◽  
pp. 1221-1226 ◽  
Author(s):  
Lei Shi ◽  
Hai-Yang Liu ◽  
Han Shen ◽  
Jun Hu ◽  
Guo-Liang Zhang ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Halogen Atom ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Phenyl Group ◽  
Atomic Weight ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Fluorescence Quantum Yields ◽  
Atom Effect

A series of mono-hydroxyl corrole bearing a fluorine (1), chlorine (2), bromine (3) and iodine (4) atom on its 10-phenyl group have been synthesized. Fluorescence spectroscopy shows that the halogen atom at meso-phenyl group of corroles exhibit significant heavy-atom effect on their photophysical properties. Fluorescence quantum yields and the lifetime of these corroles decrease with the increasing of the atomic weight of halogen atoms. The quenching of the fluorescence could be interpreted in terms of a heavy atom-induced increase in intersystem crossing from S1 to T1. The intersystem crossing rate constant of these corroles were also determined by transient fluorescence spectra.

Solvent Effects on the Fluorescence Properties of Methyldihydroquinolinones

1991 ◽  
Vol 46 (9) ◽  
pp. 823-828 ◽  
Author(s):  
Snezhana Bakalova
Keyword(s):  
Solvent Effects ◽  
Fluorescence Spectra ◽  
General Type ◽  
Fluorescence Enhancement ◽  
Quantum Yields ◽  
Aprotic Solvents ◽  
Absorption And Fluorescence Spectra ◽  
Solvent Interaction ◽  
Fluorescence Quantum Yields ◽  
Protic Solvents

Abstract The absorption and fluorescence spectra and the fluorescence quantum yields of two methyl-2,3- dihydro-4(1H)-quinolinones in various solvents are reported. In some solvents deuteration-induced fluorescence enhancement has been observed. The solvent effects in aprotic solvents are consistent with the general type of solvent interaction. For protic solvents, solute-solvent complexation in the excited state is suggested

Electronic Absorption, MCD and Fluorescence Studies on Phthalocyaninatosilicon Covalently Linked to One or Two TEMPO Radicals

1999 ◽  
Vol 03 (06) ◽  
pp. 439-443 ◽  
Author(s):  
KAZUYUKI ISHII ◽  
YOSHIHARU HIROSE ◽  
NAGAO KOBAYASHI
Keyword(s):  
Electronic Absorption ◽  
Fluorescence Spectra ◽  
Quantum Yields ◽  
Electronic Interaction ◽  
Excited Singlet ◽  
Excited Triplet ◽  
Fluorescence Studies ◽  
Fluorescence Quantum Yields ◽  
Allowed Transition ◽  
Covalently Linked

The UV-vis absorption, MCD and fluorescence spectra of phthalocyaninatosilicon ( SiPc ) covalently linked to one or two TEMPO radicals have been studied in comparison with those of (dihydroxy) SiPc . The electronic absorption and MCD spectra show little change on substitution of TEMPO radicals, indicating that the electronic interaction between excited singlet SiPc (1 SiPc *) and doublet TEMPO (2 TEMPO ) is very weak or non-existent. In contrast, fluorescence quantum yields decrease markedly with increasing number of TEMPO radicals. This result is interpreted reasonably by assuming that the decay from 1 SiPc * to excited triplet SiPc (3 SiPc *) partially becomes a spin-allowed transition owing to the interaction between 3 SiPc * and 2 TEMPO .

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