Germanium triazatetrabenzcorrole and germanium phthalocyanine: Synthesis, fluorescence and singlet oxygen generation

2018 ◽  
Vol 22 (09n10) ◽  
pp. 847-852 ◽  
Author(s):  
Xian-Fu Zhang ◽  
Xiaojie Sun
Keyword(s):  
Singlet Oxygen ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
Fluorescence Emission Spectra ◽  
Oxygen Generation ◽  
Fluorescence Quantum Yields ◽  
Singlet Oxygen Generation

The synthesis, fluorescence properties and singlet oxygen generation capability of germanium tetrabenzotriazacorrole (LGeTBC), germanium phthalocyanine (Cl[Formula: see text]GePc) and their derivatives are described. Measurements include UV-vis absorption spectra, fluorescence emission spectra, fluorescence quantum yields fluorescence lifetimes, and singlet delta oxygen quantum yields. LGeTBC and its derivatives exhibit quite different spectral and fluorescence properties from their phthalocyanine precursor. Both LGeTBC and Cl[Formula: see text]GePc show high singlet delta oxygen quantum yields and suitable fluorescence quantum yields, indicating that they can act as good singlet oxygen photosensitizers for photodynamic therapy.

Investigation of a novel triazatetrabenzcorrole photosensitizer

2002 ◽  
Vol 06 (07) ◽  
pp. 484-488 ◽  
Author(s):  
Zhenglin Song ◽  
Fushi Zhang ◽  
Xue Li ◽  
Shek-Kiu Chan ◽  
Fuqun Zhao ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Sulfo Groups

A novel phthalocyanine-like photosensitizer, oxophosphorus(V) tetrasulfotriaza-tetrabenzcorrole ( POTBCS 4), has been synthesized. Its structure and absorption spectrum are unique. POTBCS 4 has an axial P = O group and peripheral sulfo groups. The fluorescence emission spectra, fluorescence quantum yield and quantum yield of singlet oxygen generation have been studied. The uptake and the photodynamic activities against HeLa cells were measured. The results indicated that POTBCS 4 was a potential photosensitizer for photodynamic therapy (PDT).

Properties of singlet- and triplet-excited states of hemicyanine dyes

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Daniel Mártire ◽  
Walter Massad ◽  
Hernán Montejano ◽  
Mónica Gonzalez ◽  
Paula Caregnato ◽  
...  
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Laser Flash ◽  
Quantum Yields ◽  
Triplet States ◽  
Fluorescence Emission Spectra ◽  
Fluorescence Quantum Yields ◽  
Hemicyanine Dyes

AbstractThe fluorescence emission spectra and fluorescence quantum yields of hemicyanine dyes LDS 698, LDS 722, and LDS 730 were measured in different media. No transient species was detected in the laser flash-photolysis experiments performed with Ar-saturated solutions of the dyes in methanol. However, in the presence of 0.08 M potassium iodide, the absorption of the triplet states was clearly observed. Oxygen consumption measurements in the absence and presence of a chemical trap (furfuryl alcohol) in MeOH: H2O (φ r = 1: 1) solutions of the dyes containing KI confirmed the generation of singlet molecular oxygen.

Bis-indole substituted phthalocyanines: Photophysical and photochemical properties

2020 ◽  
Vol 25 (01) ◽  
pp. 66-74
Author(s):  
Kevser Harmandar ◽  
Esra N. Kaya ◽  
Mehmet F. Saglam ◽  
Ibrahim F. Sengul ◽  
Devrim Atilla
Keyword(s):  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Spectral Data ◽  
Quantum Yields ◽  
Oxygen Generation ◽  
Fluorescence Quantum Yields ◽  
H Nmr ◽  
Singlet Oxygen Generation ◽  
Photochemical Properties ◽  
C Nmr

Tetra substituted peripheral and non-peripheral Zn(II) phthalocyanines were successfully synthesized employing 4-(bis(3-methyl-1H-indol-2-yl)methyl)phenol as a starting material. The structure of these synthesized compounds was confirmed using 1H NMR, [Formula: see text]C NMR, infrared (IR), UV-vis, and MALDI-TOF spectral data. The photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation) properties of all synthesized peripheral and non-peripheral compounds were investigated in order to determine the potential of these compounds for application in photodynamic therapy.

Fluorescence Lifetime Studies of Crude Oils

1994 ◽  
Vol 48 (8) ◽  
pp. 977-984 ◽  
Author(s):  
Xin Wang ◽  
Oliver C. Mullins
Keyword(s):  
Energy Transfer ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Crude Oils ◽  
Fluorescence Lifetimes ◽  
Concentration Effects ◽  
Fluorescence Emission Spectra ◽  
High Concentrations ◽  
Lifetime Studies

The fluorescence lifetimes of a series of crude oils at various concentrations have been measured for UV-visible excitation and emission wavelengths. The lifetime results are compared with fluorescence spectra and quantum yields for these solutions. The concentration effects of energy transfer and quenching are large and result in a significant decrease in fluorescence lifetimes for high concentrations and for heavy crude oils. Thus, radiationless processes dominate in energy transfer. At high concentrations, energy transfer produces large red shifts in fluorescence emission spectra, while quenching produces a large reduction in quantum yields. Stern-Volmer analyses of lifetime and quenching data show a linear dependence of energy transfer and quenching rates on concentration. The rate constants are consistent with collisions which are very efficient at energy transfer and quenching, and the rates of these two processes are comparable.

Symmetrical phthalocyanine bearing four triptycene moieties: Synthesis, photophysical and singlet oxygen generation

2019 ◽  
Vol 23 (09) ◽  
pp. 990-1000 ◽  
Author(s):  
Shaya Y. Al-Raqa ◽  
Bader S. Ghanem ◽  
Esra Nur Kaya ◽  
Mahmut Durmuş ◽  
Mohamed E. El-Khouly
Keyword(s):  
Singlet Oxygen ◽  
Chemical Method ◽  
Visible Region ◽  
Quantum Yields ◽  
Nanosecond Laser ◽  
Fluorescence Lifetimes ◽  
Absorption Bands ◽  
Oxygen Generation ◽  
Metal Free ◽  
Singlet Oxygen Generation

Novel metal-free (7) and zinc(II) (8) phthalocyanine derivatives bearing four substituted triptycene moieties were synthesized and fully characterized by various spectroscopic methods including 1H-NMR, 13C-NMR, mass, FT-IR and UV-vis. Photophysical and photochemical properties such as electronic absorption, fluorescence emission, fluorescence lifetimes and singlet oxygen generation were investigated in toluene. The UV-vis spectra of 7 and 8 exhibited absorption bands in the visible region. The fluorescence lifetimes of 7 and 8 phthalocyanines were found to be 6.2 and 3.6 ns, respectively. The ability of the examined zinc(II) (8) and metal-free (7) to produce the singlet oxygen has been determined by both chemical and direct methods. While the chemical method 1,3-diphenylisobenzofuran (DPBF) as a singlet oxygen quencher was used in the first method, the direct determination has been done by recording the weak emission band of the singlet oxygen in the near-infrared region (1270 nm). From the direct process, the quantum yields of the singlet oxygen were found to be 0.28 (for 7) and 0.60 (for 8) and similar values were also obtained by the chemical method. The fluorescence quenching behavior of the studied phthalocyanine compounds (8 and 7) by electron-accepting 1,4 benzoquinone (BQ) was also studied in toluene. The powerful nanosecond laser flash photolysis technique was also employed to record the transient absorption spectra of the long-lived triplet states of the investigated compounds.

Visible and Near-Infrared Fluorescence of Crude Oils

1995 ◽  
Vol 49 (6) ◽  
pp. 754-764 ◽  
Author(s):  
Taggart D. Downare ◽  
Oliver C. Mullins
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Crude Oils ◽  
Excitation Wavelength ◽  
Fluorescence Emission Spectra ◽  
Fluorescence Quantum Yields ◽  
Oil Type

Fluorescence emission spectra and absolute quantum yields have been measured for ten diverse crude oils at various concentrations over a broad range of excitation and emission wavelengths in the visible and the near-infrared. Energy transfer produces large red shifts and large widths in the fluorescence emission spectra for shorter wavelength excitation particularly for heavier crude oils. However, the effects of energy transfer are nearly absent for near-infrared excitation; all crude oils exhibit nearly the same emission spectra for long wavelength excitation. In addition, the fraction of emission resulting from collisional energy transfer relative to nascent emission is almost independent of oil type; it is governed by quantum yield characteristics. Absolute fluorescence quantum yields of ten crude oils (and three rhodamine dyes for validation) were measured with respect to scattering of latex microspheres in distilled water. Fluorescence quantum yields vary systematically with crude oil type as well as excitation wavelength; quantum yields are lower for high fluorophore concentrations (heavy crude oils) and for longer wavelength excitation. Stern-Volmer analyses of the quantum yields indicate that simple models apply and show the relative quenching rates for different excitation wavelengths.

Singlet oxygen generation of subphthalocyanine-fused dimer and trimer

2020 ◽  
Vol 24 (01n03) ◽  
pp. 211-219
Author(s):  
Rei Fujishiro ◽  
Hayato Sonoyama ◽  
Yuki Ide ◽  
Takuya Fujimura ◽  
Ryo Sasai ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Quantum Yields ◽  
Absorption Bands ◽  
Low Light ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Near Ir ◽  
Interesting Class ◽  
High Fluorescence ◽  
Significant Wavelength

Subphthalocyanine (SubPc) macrocycles are known as an interesting class of nonplanar aromatic dyes. Despite documented high fluorescence and singlet oxygen quantum yields, the properties of SubPcs in photodynamic therapy (PDT) are underestimated, because their absorption bands do not reach a significant wavelength range. With this in mind, we combined a SubPc ring and a SubPc ring by introducing a common benzene ring and obtained a SubPc dimer (2) and trimer (3) with the Q-band at the near-IR region, owing to the expansion of the [Formula: see text] electron conjugated system. In this study, we reported 1O2 generation abilities of 2 and 3based on the applied absolute singlet oxygen quantum yields ([Formula: see text]absolute). Subsequent research revealed that 2 and 3 showed the potential to generate 1O2 to not only in toluene but also in DMSO. Although the photocytotoxicity of 2 and 3 were investigated upon photo-irradiation with a low light dose of approximately 1.5 J/cm2, 2 and 3 showed almost negligible toxic properties toward HEp2 cells.

Synthesis, characterization, photophysicochemical properties and theoretical study of novel zinc phthalocyanine containing four tetrathia macrocycles

2018 ◽  
Vol 22 (01n03) ◽  
pp. 77-87 ◽  
Author(s):  
Mohamad Albakour ◽  
Gülenay Tunç ◽  
Büşra Akyol ◽  
Sinem Tuncel Kostakoğlu ◽  
Savaş Berber ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Energy Structure ◽  
Fluorescence Measurement ◽  
Oxygen Generation ◽  
Fluorescence Quantum Yields ◽  
H Nmr ◽  
Ft Ir ◽  
Phthalocyanine Derivative

In this work, Zn(II) phthalocyanine derivative (TTU-Pc) bearing 13-membered tetrathia macrocycles was synthesized, and the novel Zn(II) phthalocyanine derivative was fully characterized by elemental analysis and general spectroscopic methods such as MALDI-TOF mass, FT-IR, UV-vis and [Formula: see text]H-NMR. The synthesized phthalocyanine derivative has quite limited solubility in most of the common organic solvents. Fluorescence measurement was conducted for this Zn(II)phthalocyanine to estimate its fluorescence quantum yields. The singlet oxygen generation ability was also examined to investigate its photosensitizer properties. General trends were described for quantum yields of fluorescence, photodegradation and singlet oxygen quantum yields of this compound. The electrochemical properties of the molecule were investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). In addition, the lowest energy structure, the electronic structure and frontier molecular orbitals were calculated in DFT and the excitation spectrum was obtained by TDDFT calculations. We found that our computational and experimental results were in agreement.

scholarly journals Photoluminescence in m-carborane–anthracene triads: a combined experimental and computational study

2018 ◽  
Vol 6 (42) ◽  
pp. 11336-11347 ◽  
Author(s):  
Mahdi Chaari ◽  
Zsolt Kelemen ◽  
José Giner Planas ◽  
Francesc Teixidor ◽  
Duane Choquesillo-Lazarte ◽  
...  
Keyword(s):  
Computational Study ◽  
Fluorescence Emission ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Aggregate State ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

m-Carborane has demonstrated to be a perfect platform to boost the fluorescence properties of anthracene, giving rise to high fluorescence quantum yields in solution and also retaining fluorescence emission in the aggregate state.

New heterogeneous photosensitizers with phthalocyanine molecules covalently linked to aminopropyl silica gel

2011 ◽  
Vol 15 (07n08) ◽  
pp. 718-726 ◽  
Author(s):  
Nina A. Kuznetsova ◽  
Olga A. Yuzhakova ◽  
Marina G. Strakhovskaya ◽  
Anna O. Shumarina ◽  
Anton S. Kozlov ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Silica Gel ◽  
Fluorescence Spectra ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Oxygen Generation ◽  
E Coli ◽  
Singlet Oxygen Generation ◽  
Aqueous Suspensions ◽  
Covalently Linked

New heterogeneous photosensitizers were synthesized, in which phthalocyanines of zinc and aluminum, tetrasubstituted at non-peripheral positions with modified thiophenyl groups, were grafted to aminopropyl silica gel. The absorption and fluorescence spectra, and the quantum yields of fluorescence and photosensitized singlet oxygen generation were estimated for aqueous suspensions of these sensitizers. It is shown that upon photoexcitation, silica gel-bound phthalocyanines produce singlet oxygen and display photobactericidal activity against bacteria E. coli.

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