Singlet oxygen quantum yields and photostability of planar binuclear phthalocyanines

2017 ◽  
Vol 21 (12) ◽  
pp. 844-849
Author(s):  
Sergei G. Makarov ◽  
Günter Schnurpfeil ◽  
Elena A. Rychagova ◽  
Sergey Yu. Ketkov ◽  
Olga N. Suvorova ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Quantum Yield ◽  
Dft Calculations ◽  
Singlet Oxygen ◽  
Near Infrared ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Photooxidative Stability

The singlet oxygen ([Formula: see text]O[Formula: see text] quantum yield of the near-infrared absorbing ([Formula: see text] [Formula: see text] 839 nm) planar [Formula: see text]-conjugated binuclear zinc phthalocyanine (ZnPc) was measured and compared to the [Formula: see text]O[Formula: see text] quantum yields of the mononuclear and the planar binuclear phthalocyanine without [Formula: see text]-conjugation between Pc rings. In addition, the photooxidative stability of the [Formula: see text]-conjugated binuclear Pc was determined and compared to the stabilities of the mononuclear ZnPc and the known near-infrared photosensitizer, zinc tetra-tert-butylnaphthalocyanine ([Formula: see text] 761 nm). The results are explained by DFT calculations and cyclic voltammetry.

Synthesis, photophysicochemical properties and TD-DFT calculations of tetrakis(2-benzoyl-4-chlorophenoxy) phthalocyanines

2014 ◽  
Vol 18 (04) ◽  
pp. 326-335 ◽  
Author(s):  
Yusuf Yılmaz ◽  
John Mack ◽  
M. Kasım Şener ◽  
Mehmet Sönmez ◽  
Tebello Nyokong
Keyword(s):  
Quantum Yield ◽  
Dft Calculations ◽  
Triplet State ◽  
Singlet Oxygen ◽  
Quantum Yields ◽  
Visible Absorption ◽  
H Nmr ◽  
Wide Range ◽  
Td Dft ◽  
The Impact

The synthesis of metal free, magnesium and zinc tetrakis(2-benzoyl-4-chlorophenoxy) phthalocyanine derivatives (2–4) is described along with their characterization by elemental analysis, IR, UV-visible absorption, and 1 H NMR spectroscopy and mass spectrometry. Trends observed in the fluorescence, triplet state, singlet oxygen and photodegradation quantum yields and the triplet state lifetimes are also analyzed. The compounds exhibit high solubility in a wide range of organic solvents and no evidence of aggregation was observed over a wide concentration range. The Zn ( II ) complex (4) was found to have a very high singlet oxygen quantum yield (ΦΔ = 0.78) in dimethylsulfoxide (DMSO) and a reasonably large triplet state quantum yield (ΦT = 0.82). The photophysical and photochemical properties clearly demonstrate that these compounds could prove useful in singlet oxygen applications such as photodynamic therapy (PDT). DFT and TD-DFT calculations were used to assess the impact of the positional isomerism of the 2-benzoyl-4-chlorophenoxy substituents on the electronic structures and optical spectroscopy.

Synthesis, photophysicochemical studies of adjacently tetrasubstituted binaphthalo-phthalocyanines

2005 ◽  
Vol 09 (05) ◽  
pp. 316-325 ◽  
Author(s):  
Itumeleng Seotsanyana-Mokhosi ◽  
Ji-Yao Chen ◽  
Tebello Nyokong
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Triplet State ◽  
Singlet Oxygen ◽  
Photophysical Properties ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Triplet Excited State ◽  
General Increase ◽  
Photochemical Behavior

Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.

Influence of cyclodextrins on the fluorescence, photostability and singlet oxygen quantum yields of zinc phthalocyanine and naphthalocyanine complexes

2003 ◽  
Vol 07 (06) ◽  
pp. 439-446 ◽  
Author(s):  
Prudence Tau ◽  
Abimbola O. Ogunsipe ◽  
Suzanne Maree ◽  
M. David Maree ◽  
Tebello Nyokong
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Inclusion Complexes ◽  
Photophysical Properties ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cyclodextrin Inclusion Complexes ◽  
Cyclodextrin Inclusion ◽  
Zinc Phthalocyanines

The effects of formation of cyclodextrin inclusion complexes on the photochemical and photophysical properties of zinc phthalocyanine ( ZnPc ) and various peripherally substituted zinc phthalocyanines as well as zinc naphthalocyanine ( ZnNPc ) are investigated. The cyclodextrins employed were the hydroxypropyl-γ-cyclodextrin and unsubstituted β-cyclodextrin. Job's plots were employed to confirm the stoichiometry of the inclusion complexes and showed 2:1 and 4:1 (cyclodextrin:phthalocyanine) inclusion behavior. The phthalocyanine inclusion complexes showed larger singlet oxygen quantum yield (ϕΔ) values when compared to the free phthalocyanines before inclusion, for complexes 1 (zinc naphthalocyanine), 2 (zinc tetranitrophthalocyanine) and 4 (zinc tetra-tert-butylphenoxyphthalocyanine). The fluorescence quantum yields generally remained unchanged following inclusion.

Photodynamic antimicrobial activity of benzimidazole substituted phthalocyanine when conjugated to Nitrogen Doped Graphene Quantum Dots against Staphylococcus aureus

2021 ◽  
Vol 20 (2) ◽  
pp. 175-191
Author(s):  
Pinar Sen ◽  
Nnamdi Nwahara ◽  
Tebello Nyokong
Keyword(s):  
Staphylococcus Aureus ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Graphene Quantum Dots ◽  
Life Time ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

In this study, peripherally benzimidazole unit substituted ZnPc (1) and its conjugation to nitrogen doped graphene quantum dot (NGQD) as potential phthalocyanine support via π-π stacking have been presented and fully characterized. The bottom-up solution-based synthesized NGQDs was conjugated non-covalently to zinc phthalocyanine to form NGQDs-Pc nanoconjugates. The photophysical and photochemical properties of both such as absorption, fluorescence, fluorescence life time, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions. We observed a decrease in the fluorescence quantum yields with a corresponding increase in the triplet quantum yield and singlet oxygen quantum yield of the nanoconjugates in comparison to the phthalocyanine complex alone. Photodynamic antimicrobial chemotherapy activities (PACT) of ZnPc alone and its nanoconjugate were determined towards Staphylococcus aureus.

scholarly journals Ruthenium-based PACT agents based on bisquinoline chelates: synthesis, photochemistry, and cytotoxicity

2021 ◽  
Author(s):  
Anja Busemann ◽  
Ingrid Flaspohler ◽  
Xue-Quan Zhou ◽  
Claudia Schmidt ◽  
Sina K. Goetzfried ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Cancer Cells ◽  
Cellular Uptake ◽  
Ruthenium Complex ◽  
Human Cancer ◽  
Light Irradiation ◽  
Quantum Yields ◽  
Light Activation ◽  
Human Cancer Cells

AbstractThe known ruthenium complex [Ru(tpy)(bpy)(Hmte)](PF6)2 ([1](PF6)2, where tpy = 2,2’:6’,2″-terpyridine, bpy = 2,2’-bipyridine, Hmte = 2-(methylthio)ethanol) is photosubstitutionally active but non-toxic to cancer cells even upon light irradiation. In this work, the two analogs complexes [Ru(tpy)(NN)(Hmte)](PF6)2, where NN = 3,3'-biisoquinoline (i-biq, [2](PF6)2) and di(isoquinolin-3-yl)amine (i-Hdiqa, [3](PF6)2), were synthesized and their photochemistry and phototoxicity evaluated to assess their suitability as photoactivated chemotherapy (PACT) agents. The increase of the aromatic surface of [2](PF6)2 and [3](PF6)2, compared to [1](PF6)2, leads to higher lipophilicity and higher cellular uptake for the former complexes. Such improved uptake is directly correlated to the cytotoxicity of these compounds in the dark: while [2](PF6)2 and [3](PF6)2 showed low EC50 values in human cancer cells, [1](PF6)2 is not cytotoxic due to poor cellular uptake. While stable in the dark, all complexes substituted the protecting thioether ligand upon light irradiation (520 nm), with the highest photosubstitution quantum yield found for [3](PF6)2 (Φ[3] = 0.070). Compounds [2](PF6)2 and [3](PF6)2 were found both more cytotoxic after light activation than in the dark, with a photo index of 4. Considering the very low singlet oxygen quantum yields of these compounds, and the lack of cytotoxicity of the photoreleased Hmte thioether ligand, it can be concluded that the toxicity observed after light activation is due to the photoreleased aqua complexes [Ru(tpy)(NN)(OH2)]2+, and thus that [2](PF6)2 and [3](PF6)2 are promising PACT candidates. Graphic abstract

New soluble 4-(4-formyl-2,6-dimethoxyphenoxy) substituted phthalocyanines: Synthesis, characterization, photophysical and photochemical properties

2021 ◽  
pp. 1-10
Author(s):  
Ibrahim Erden ◽  
Betül Karadoğan ◽  
Fatma Aytan Kılıçarslan ◽  
Göknur Yaşa Atmaca ◽  
Ali Erdoğmuş
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Fluorescence Quantum Yield ◽  
Metal Ion ◽  
Mass Spectra ◽  
Quantum Yields ◽  
Therapeutic Outcomes ◽  
Ft Ir ◽  
Photochemical Properties ◽  
New Compounds

This work describes the synthesis, spectral and fluorescence properties of bis 4-(4-formyl-2,6-dimethoxyphenoxy) substituted zinc (ZnPc) and magnesium (MgPc) phthalocyanines. The new compounds have been characterized by elemental analysis, UV-Vis, FT-IR, 1H-NMR and mass spectra. Afterward, the effects of including metal ion on the photophysicochemical properties of the complexes were studied in biocompatible solvent DMSO to analyze their potential to use as a photosensitizer in photodynamic therapy (PDT). The fluorescence and singlet oxygen quantum yields were calculated as 0.04–0.15 and 0.70–0.52 for ZnPc and MgPc, respectively. According to the results, MgPc has higher fluorescence quantum yield than ZnPc, while ZnPc has higher singlet oxygen quantum yield than MgPc. The results show that the synthesized complexes can have therapeutic outcomes for cancer treatment.

scholarly journals Red and Near-Infrared Absorbing Dicyanomethylene Squaraine Cyanine Dyes: Photophysicochemical Properties and Anti-Tumor Photosensitizing Effects

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2083
Author(s):  
Tiago D. Martins ◽  
Eurico Lima ◽  
Renato E. Boto ◽  
Diana Ferreira ◽  
José R. Fernandes ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Near Infrared ◽  
Cyanine Dyes ◽  
Quantum Yields ◽  
Squaraine Dyes ◽  
Photodynamic Activity ◽  
Photochemical Properties ◽  
Radiation Treatments ◽  
Species Production

Photodynamic therapy is a medical modality developed for the treatment of several diseases of oncological and non-oncological etiology that requires the presence of a photosensitizer, light and molecular oxygen, which combined will trigger physicochemical reactions responsible for reactive oxygen species production. Given the scarcity of photosensitizers that exhibit desirable characteristics for its potential application in this therapeutic strategy, the main aims of this work were the study of the photophysical and photochemical properties and the photobiological activity of several dicyanomethylene squaraine cyanine dyes. Thus, herein, the study of their aggregation character, photobleaching and singlet oxygen production ability, and the further application of the previously synthesized dyes in Caco-2 and HepG2 cancer cell lines, to evaluate their phototherapeutic effects, are described. Dicyanomethylene squaraine dyes exhibited moderate light-stability and, despite the low singlet oxygen quantum yields, were a core of dyes that exhibited relevant in vitro photodynamic activity, as there was an evident increase in the toxicity of some of the tested dyes exclusive to radiation treatments.

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 Photophysical Investigation of near Infrared Emitting Lanthanoid Complexes Incorporating Tris(2-Naphthoyl)methane as a New Antenna Ligand

2019 ◽  
Author(s):  
Laura Abad Galán ◽  
Satoshi Wada ◽  
Lee Cameron ◽  
Alexandre N. Sobolev ◽  
Yasuchika Hasegawa ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Quantitative Data ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Radiative Decays ◽  
Quantum Yields ◽  
Mononuclear Complexes ◽  
Deuterated Analogue ◽  
Antenna Ligand

A conjugated <i>β</i>-triketone, tris(2-naphthoyl)methane (<b>tnm</b>H), has been synthesized and successfully utilized as an antenna moiety for sensitization of the trivalent lanthanoids Eu<sup>3+</sup><sub>,</sub>Sm<sup>3+</sup><sub>,</sub>Yb<sup>3+</sup>and Nd<sup>3+</sup>, in an isomorphous series of mononuclear complexes formulated as [Ln(<b>tnm</b>)<sub>3</sub>(DMSO)<sub>2</sub>] (Ln<sup>3+ </sup>= Nd<sup>3+</sup>, Sm<sup>3+</sup>, Eu<sup>3+</sup>, Gd<sup>3+</sup>and Yb<sup>3+</sup>). The photophysical properties of the materials were characterized as comprehensively as possible, with overall quantum yields, intrinsic quantum yields based on calculated radiative decays, and sensitization efficiencies reported. This investigation improves understanding of the sensitization processes occurring in the near-infrared (NIR) region systems in particular, where quantitative data is currently scarce. In fact, the [Yb(<b>tnm</b>)<sub>3</sub>(DMSO)<sub>2</sub>] and its deuterated analogue, [Yb(<b>tnm</b>)<sub>3</sub>(<i>d<sub>6</sub>-</i>DMSO)<sub>2</sub>], present high values of overall quantum yield of 4% and 6%, respectively, which makes them useful and readily accessible references for future investigation of NIR-emitting systems.

Sign in / Sign up

Export Citation Format

Share Document