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.

New peripherally substituted lutetium mono and bis phthalocyanines: Synthesis and comparative photophysical and photochemical properties

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1542-1550
Author(s):  
Nagihan Kocaağa ◽  
Öznur Dülger Kutlu ◽  
Ali Erdoğmuş
Keyword(s):  
Mass Spectrometry ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Synthesis And Characterization ◽  
Type Ii ◽  
H Nmr ◽  
Photochemical Properties

In this study, the synthesis and characterization of mono-(phthalocyaninato) lutetium(III) (1-Cl and 1-F) [Lu[Formula: see text](AcO)(Pc)] (Pc [Formula: see text] phthalocyaninato, AcO [Formula: see text] acetate) and bis-(phthalocyaninato) lutetium(III) (2-Cl and 2-Br) [Lu[Formula: see text]Pc[Formula: see text]] bearing halogenated (F, Cl and Br) phenoxy–phenoxy groups are described and verified by IR, [Formula: see text]H-NMR, UV-vis and mass spectrometry. Photochemical and photophysical properties of 1-F, 1-Cl 2-Cl and 2-Br in DMSO are also presented. A comparison between photophysical and photochemical parameters of mono and bis derivatives showed that mono phthalocyanines are better photosensitizers than bis phthalocyanines. Photophysical and photochemical properties of phthalocyanines are very useful for photodynamic therapy applications. Singlet oxygen quantum yields [Formula: see text] give an indication of the potential of the complexes as photosensitizers in photodynamic therapy applications. The chloro, fluoro, bromo-phenoxy–phenoxy substituted mono-(phthalocyaninato) lutetium(III) complexes (1-Cl and 1-F) gave good singlet oxygen quantum yields (from 0.86 to 0.80) in DMSO. Thus, these complexes show potential as Type II photosensitizers for PDT of cancer.

scholarly journals Chloro- and BF2bdk-substituted dithienylethene: Synthesis, photophysical properties, and optical switching behavior

2020 ◽  
pp. 174751982095141
Author(s):  
Zhiqiang Lu ◽  
Wenbo Yang ◽  
Yanhui Bai ◽  
Mo Wang ◽  
Zixu Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Optical Switching ◽  
High Resolution Mass Spectrometry ◽  
Photophysical Properties ◽  
Red Light ◽  
Switching Behavior ◽  
Polar Solvents ◽  
H Nmr ◽  
Resolution Mass ◽  
C Nmr

A novel chloro- and BF2bdk-substituted dithienylethene derivative, in which a chlorine atom and a difluoroboron β-diketonate (BF2bdk) group are appended at the termini of the dithienylethene core, is developed. The structure was confirmed by 1H NMR, 13C NMR, and high-resolution mass spectrometry (electrospray ionization). It displayed solvent-dependent photophysical properties, and blue/red light-triggered optical switching behavior in nonpolar or less polar solvents.

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.

Heavy metal effects on physicochemical properties of non-aggregated azaphthalocyanine derivatives

2012 ◽  
Vol 16 (07n08) ◽  
pp. 817-825 ◽  
Author(s):  
Ahmad Tuhl ◽  
Saad Makhseed ◽  
Petr Zimcik ◽  
Nouria Al-Awadi ◽  
Veronika Novakova ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Central Metal ◽  
Generation Efficiency ◽  
Oxygen Generation ◽  
H Nmr ◽  
Singlet Oxygen Generation ◽  
Band Position ◽  
Metal Effect

Two series of peripherally substituted azaphthalocyanines (AzaPcs) containing different transition metals ( Al(III), Zn(II), Ga(III), In(III) and Fe(II) ) were synthesized and studied for their photophysical properties. As confirmed by UV-vis and1H NMR analyses, the non-aggregation behavior was effectively induced by the applied bulky peripheral substituents which had no effect on the photophysical properties. Tuning the Q-band position was clearly achievable by using different central heavy metals which have considerable effects on the fluorescence quantum yield and singlet oxygen generation efficiency. This comparative study showed an interesting linear relationship between the former and atomic number of the central metal. The indium containing complexes exhibited the best result due to the heavy metal effect and therefore could be promoted as a potential photosensitizer in photodynamic therapy (PDT) application.

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.

Synthesis of Ag(II) 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin and its facile demetalation to 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin

2016 ◽  
Vol 20 (05) ◽  
pp. 656-661
Author(s):  
Sasitha Vidyarini Ravindran ◽  
Anuj Krishnasundar Pennathur ◽  
G. Nandhini Devi ◽  
Gautam Pennathur
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Trifluoroacetic Acid ◽  
Time Interval ◽  
Sodium Sulphide ◽  
Free Base ◽  
H Nmr ◽  
Mild Conditions ◽  
One Step ◽  
Uv Visible

A novel one-step strategy for the synthesis of 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin using AgIIOBP is described. AgIIOBP was synthesized and was. Bromination of AgIITPP was carried out in a one-step reaction by varying the subsequently demetalated using H2S time interval and stoichiometric addition of Br2. The molecular weight of the halogenated porphyrin was confirmed by MALDI-TOF mass spectrometry. The synthesis of Ag(II) 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin was followed by demetalation of Ag(II) ion from the halogenated porphyrin. The demetalation of was carried out under mild conditions using sodium sulphide in trifluoroacetic acid. The time taken for the demetalation was considerably lesser than previously reported and which facilitated a simple way for the isolation of the final product in good yield. The yield of the free base was 98%. The formation of the product and purity was confirmed by 1H NMR, Mass spectrometry. UV-visible spectrophotometer clearly showed the appearance of a characteristic Q-band of the octa-brominated porphyrin.

Synthesis, spectroscopy and photochemistry of dyads and triads with porphyrins and bis(terpyridine)ruthenium(II) complex

2006 ◽  
Vol 10 (08) ◽  
pp. 1049-1060 ◽  
Author(s):  
Prashanth Kumar Poddutoori ◽  
Premaladha Poddutoori ◽  
Bhaskar G. Maiya
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Soret Band ◽  
Differential Pulse ◽  
Free Base ◽  
Triplet Energy ◽  
Polar Solvents ◽  
H Nmr ◽  
Ligand Charge Transfer ◽  
Triplet Energy Transfer

A bis(terpyridine)ruthenium(II) complex ([Ru]2+) was covalently connected via a floppy - OCH 2 CH 2 O - spacer to the free-base porphyrin (H) or zinc(II) porphyrin (Zn) or both, to obtain dyads ([HRu]2+, [ZnRu]2+) and triads ([HRuH]2+, [ZnRuH]2+, [ZnRuZn]2+). These compounds have been fully characterized by MALDI, UV-vis, 1 H NMR (1D and 1 H -1 H COSY) spectroscopies, and also by the cyclic and differential pulse voltammetric techniques. Absorption spectroscopy of these newly synthesized compounds shows that significant exciton coupling exists in non-polar solvents (cyclohexane and toluene) between the porphyrin ring and the bis(terpyridine)ruthenium(II) complex. Upon excitation within the Soret band of [HRu]2+/[HRuH]2+, free-base porphyrin fluorescence was found to be strongly quenched in non-polar and weakly quenched in polar solvents, probably due to ‘singlet-triplet’ energy transfer from the free-base porphyrin to the [Ru]2+ complex. Whereas, in [ZnRu]2+/[ZnRuZn]2+, zinc(II) porphyrin fluorescence was quantitatively and reasonably quenched in non-polar and polar solvents, respectively by mainly electron transfer from the zinc(II) porphyrin to the [Ru]2+ complex. The solvent plays a crucial role in the photophysical properties of these compounds, since the energy of the triplet metal-to-ligand charge-transfer (3MLCT) excited state is influenced by the polarity of the medium. Finally, [ZnRuH]2+ exhibits the combined fluorescence properties of [HRu]2+ and [ZnRu]2+ but the observed additional quenching in non-polar solvents for the zinc(II) porphyrin component is explained by energy transfer from the zinc(II) porphyrin to the free-base porphyrin and/or the bis(terpyridine)ruthenium(II) complex.

scholarly journals Measurement of δ18O and δ2H of water and ethanol in wine by Off-Axis Integrated Cavity Output Spectroscopy and Isotope Ratio Mass Spectrometry

2021 ◽  
Author(s):  
Xing Wang ◽  
Henk G. Jansen ◽  
Haico Duin ◽  
Harro A. J. Meijer
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Growth Conditions ◽  
The Other ◽  
H Nmr ◽  
Cavity Output ◽  
Pre Treatment ◽  
Output Laser

AbstractThere are two officially approved methods for stable isotope analysis for wine authentication. One describes δ18O measurements of the wine water using Isotope Ratio Mass Spectrometry (IRMS), and the other one uses Deuterium-Nuclear Magnetic Resonance (2H-NMR) to measure the deuterium of the wine ethanol. Recently, off-axis integrated cavity output (laser) spectroscopy (OA-ICOS) has become an easier alternative to quantify wine water isotopes, thanks to the spectral contaminant identifier (SCI). We utilized an OA-ICOS analyser with SCI to measure the δ18O and δ2H of water in 27 wine samples without any pre-treatment. The OA-ICOS results reveal a wealth of information about the growth conditions of the wines, which shows the advantages to extend the official δ18O wine water method by δ2H that is obtained easily from OA-ICOS. We also performed high-temperature pyrolysis and chromium reduction combined with IRMS measurements to illustrate the “whole wine” isotope ratios. The δ18O results of OA-ICOS and IRMS show non-significant differences, but the δ2H results of both methods differ much more. As the δ2H difference between these two methods is mainly caused by ethanol, we investigated the possibility to deduce deuterium of wine ethanol from this difference. The results present large uncertainties and deviate from the obtained 2H-NMR results. The deviation is caused by the other constituents in the wine, and the uncertainty is due to the limited precision of the SCI-based correction, which need to improve to obtain the 2H values of ethanol as alternative for the 2H-NMR method.

scholarly journals Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

2019 ◽  
Vol 15 ◽  
pp. 2013-2019 ◽  
Author(s):  
Esther Nieland ◽  
Oliver Weingart ◽  
Bernd M Schmidt
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Visible Light ◽  
Half Life ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Partial Overlap

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.

scholarly journals Novel Acetohydrazide Pyrazole Derivatives: Design, Synthesis, Characterization and Antimicrobial Activity

2019 ◽  
Vol 31 (12) ◽  
pp. 2740-2744
Author(s):  
Anil Verma ◽  
Vinod Kumar ◽  
Ramesh Kataria ◽  
Joginder Singh
Keyword(s):  
Mass Spectrometry ◽  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Pyrazole Derivatives ◽  
Reaction Conditions ◽  
Design Synthesis ◽  
Structure Activity ◽  
Electron Withdrawing Group ◽  
Sar Study

Eleven acetohydrazide linked pyrazole derivatives were designed and synthesized via condensation of acetohyadrazide with different substituted formyl pyrazole derivatives under mild reaction conditions. Synthesized compounds were characterized on the basis of IR, NMR (1H & 13C) and mass spectrometry. The antimicrobial activities of all the compounds were screened against four bacterial and two fungal strains. Among the synthesized compounds, three compounds viz. 6b, 6c and 6d were found as efficient antimicrobial agents in reference to the standard drugs viz. ciprofloxacin and amphotericin-B. Further, structure-activity relationship (SAR) study revealed that electron-withdrawing group enhances the antimicrobial potential of synthesized derivatives as compared to other groups present in the ring. Hence, among compounds 6b-c, compound 6d could be explored further against other microbes to prove its vitality.

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