Characterization of photophysical properties of curcumin for theranostics of neurodegenerative diseases

2019 ◽  
Author(s):  
Raphael Antonio Caface ◽  
Marcelo Saito Nogueira ◽  
Francisco E. Gontijo Guimarães ◽  
Vanderlei Salvador Bagnato ◽  
Fabio Francisco Pinto ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Photophysical Properties

scholarly journals Synthesis and Characterization of a Multifunctional Conjugated Polymer

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Emerson C. G. Campos ◽  
Cristiano Zanlorenzi ◽  
Bruno F. Nowacki ◽  
Gabriela M. Miranda ◽  
Denis A. Turchetti ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Molar Mass ◽  
Photophysical Properties ◽  
Gel Permeation Chromatography ◽  
Thermal Characterization ◽  
Polymer Structure ◽  
Synthesis And Characterization ◽  
Metallic Ions ◽  
Scanning Calorimetry

This work reports the synthesis and characterization of a conjugated polymer based on fluorene and terpyridine, namely, poly[(9,9-bis(3-((S)-2-methylbutylpropanoate))fluorene-alt-6,6′-(2,2′:6′,2′′-terpyridin-6-yl)] (LaPPS71). The structure was characterized by 1H and 13C nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy. The molar mass was measured by gel permeation chromatography (GPC). As thermal characterization, the glass transition temperature (Tg) was measured by differential scanning calorimetry (DSC). The polymer structure contains two sites capable of complexation with metallic ions, affording the possibility of obtainment of independent or electronically coupled properties, depending on the complexation site. The photophysical properties were fully explored in solution and solid state, presenting ideal results for the preparation of various metallopolymers, in addition to potential application as a metamaterial, due to the presence of the chiral center in the side chains of the polymer.

Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts

Synlett ◽  
2022 ◽  
Author(s):  
Eva Bednářová ◽  
Logan R. Beck ◽  
Tomislav Rovis ◽  
Samantha L. Goldschmid ◽  
Katherine Xie ◽  
...  
Keyword(s):  
Ground State ◽  
Emission Spectroscopy ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Low Energy ◽  
Redox Potentials ◽  
Nir Light ◽  
Osmium Complexes ◽  
Absorption And Emission Spectroscopy

AbstractThe use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.1 Introduction1.1 Scope1.2 Measuring Ground-State Redox Potentials1.3 Measuring Photophysical Properties1.4 Synthesis of Osmium Complexes2 Properties of Osmium Complexes2.1 Redox Potentials of Os(L)2-Type Complexes2.2 Redox Potentials of Os(L)3-Type Complexes2.3 UV/Vis Absorption and Emission Spectroscopy3 Conclusions

Synthesis and characterization of 5-(4-carboxyphenylspermine)-10,15,20-triphenylporphyrin

2020 ◽  
Vol 24 (05n07) ◽  
pp. 802-808
Author(s):  
Chiara M.A. Gangemi ◽  
Rosalba Randazzo ◽  
Massimiliano Gaeta ◽  
Cosimo G. Fortuna ◽  
Maria E. Fragalà ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Photophysical Properties ◽  
Soret Band ◽  
Fluorescence Band ◽  
Synthesis And Characterization ◽  
Acidic Solutions ◽  
Protonation Equilibria ◽  
The Core ◽  
Aggregation Processes

We synthetized and characterized a mono spermine porphyrin derivative by NMR, UV-vis and fluorescence spectroscopy. The photophysical properties and the protonation equilibria of 5-(4-carboxyphenylspermine)-10,15,20-triphenylporphyrin have been investigated, showing that porphyrin does not aggregate in acidic solutions, differently from what occurs as soon as the core of the porphyrin is deprotonated. These aggregation processes have been detected by the rising of new fluorescence band and a significant splitting of the Soret band.

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 New Materials Based on Cationic Porphyrins Conjugated to Chitosan or Titanium Dioxide: Synthesis, Characterization and Antimicrobial Efficacy

2019 ◽  
Vol 20 (10) ◽  
pp. 2522 ◽  
Author(s):  
Kelly A. D. F. Castro ◽  
Nuno M. M. Moura ◽  
Flávio Figueira ◽  
Rosalina I. Ferreira ◽  
Mário M. Q. Simões ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photophysical Properties ◽  
Antimicrobial Photodynamic Therapy ◽  
New Materials ◽  
Solid Supports ◽  
Cationic Porphyrins ◽  
E Coli ◽  
Porphyrin Core ◽  
Post Functionalization

The post-functionalization of 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide, known as a highly efficient photosensitizer (PS) for antimicrobial photodynamic therapy (aPDT), in the presence of 3- or 4-mercaptobenzoic acid, afforded two new tricationic porphyrins with adequate carboxylic pending groups to be immobilized on chitosan or titanium oxide. The structural characterization of the newly obtained materials confirmed the success of the porphyrin immobilization on the solid supports. The photophysical properties and the antimicrobial photodynamic efficacy of the non-immobilized porphyrins and of the new conjugates were evaluated. The results showed that the position of the carboxyl group in the mercapto units or the absence of these substituents in the porphyrin core could modulate the action of the photosensitizer towards the bioluminescent Gram-negative Escherichia coli bacterium. The antimicrobial activity was also influenced by the interaction between the photosensitizer and the type of support (chitosan or titanium dioxide). The new cationic porphyrins and some of the materials were shown to be very stable in PBS and effective in the photoinactivation of E. coli bacterium. The physicochemical properties of TiO2 allowed the interaction of the PS with its surface, increasing the absorption profile of TiO2, which enables the use of visible light, inactivating the bacteria more efficiently than the corresponding PS immobilized on chitosan.

Towards the Synthesis of Mono- and Bi-Functional Amphiphilic Oligothiophenes: Organic Materials for Opto-Electronic Applications

1999 ◽  
Vol 561 ◽  
Author(s):  
R.C. Advincula ◽  
S. Inaoka ◽  
M. Park ◽  
D. Phillips ◽  
D.M. Shin
Keyword(s):  
Physical Properties ◽  
Ultrathin Films ◽  
Organic Materials ◽  
Photophysical Properties ◽  
Electronic Devices ◽  
Synthesis And Characterization ◽  
Important Class ◽  
Maldi Tof Ms ◽  
Tof Ms

ABSTRACTIn this report, we describe our initial synthesis and characterization of mono-functional and bi-functional dibromoalkyl oligothiophenes to achieve amphiphilicity and telechelic functionality. Oligothiophenes are an important class of organic materials for opto-electronic devices and display applications. We have mono-functionalized oligothiophenes by the synthesis of a quinquethiophene bromoalkyl derivative. A bi-functional sexithiophene was derived primarily by the symmetrical coupling of terthiophene derivatives. Both were synthesized using Grignard coupling and lithiation reaction methodologies. UV-Vis, IR, NMR, MALDI-TOF-MS, and DSC confirmed the structure and physical properties of the oligomers. In addition, we have also synthesized an amphiphilic diamine derivative from the reaction of hexamethylenediamine with a bromoalkyl terthiophene derivative. Using photoluminescence, the photophysical properties of the oligomers were found to be that of typical oligothiophenes. Processing as ultrathin films for devices is currently being investigated.

A family of Ru(ii) complexes built on a novel sexipyridine building block: synthesis, photophysical properties and the rare structural characterization of a triruthenium species

2015 ◽  
Vol 44 (25) ◽  
pp. 11551-11561 ◽  
Author(s):  
Baptiste Laramée-Milette ◽  
Félix Lussier ◽  
Ilaria Ciofini ◽  
Garry S. Hanan
Keyword(s):  
Structural Characterization ◽  
Building Block ◽  
Photophysical Properties ◽  
X Ray

A new sexipyridine ligand and its Ru(ii) family of complexes is described along with its characterization by electrochemical and photophysical methods as well as a rare X-ray analysis of a triruthenium polypyridine complex.

scholarly journals Synthesis and Characterization of Acridinium Dyes for Photoredox Catalysis

Synlett ◽  
2019 ◽  
Vol 30 (07) ◽  
pp. 827-832 ◽  
Author(s):  
Alexander White ◽  
Leifeng Wang ◽  
David Nicewicz
Keyword(s):  
Photophysical Properties ◽  
Direct Conversion ◽  
Systematic Investigation ◽  
Synthetic Methods ◽  
Synthesis And Characterization ◽  
Substitution Effects ◽  
Photoredox Catalysis ◽  
Methods Development

Photoredox catalysis is a rapidly evolving platform for synthetic methods development. The prominent use of acridinium salts as a sustainable option for photoredox catalysts has driven the development of more robust and synthetically useful versions based on this scaffold. However, more complicated syntheses, increased cost, and limited commercial availability have hindered the adoption of these catalysts by the greater synthetic community. By utilizing the direct conversion of a xanthylium salt into the corresponding acridinium as the key transformation, we present an efficient and scalable preparation of the most synthetically useful acridinium reported to date. This divergent strategy also enabled the preparation of a suite of novel acridinium dyes, allowing for a systematic investigation of substitution effects on their photophysical properties.

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