scholarly journals Antioxidants as Molecular Probes: Structurally Novel Dihydro-m-Terphenyls as Turn-On Fluorescence Chemodosimeters for Biologically Relevant Oxidants

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 605
Author(s):  
Víctor González-Ruiz ◽  
Jegathalaprathaban Rajesh ◽  
Ana I. Olives ◽  
Damiano Rocchi ◽  
Jorge Gómez-Carpintero ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Aqueous Media ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Fluorescence Signal ◽  
Reaction Conditions ◽  
Biologically Relevant ◽  
Fluorescence Quantum Yields ◽  
Fluorescent Response ◽  
Reactive Oxidant

One interesting aspect of antioxidant organic molecules is their use as probes for the detection and quantitation of biologically relevant reactive oxidant species (ROS). In this context, a small library of dihydroterphenyl derivatives has been synthesised and studied as fluorescent chemodosimeters for detecting reactive oxygen species and hypochlorite. The fluorescence quantum yields of these molecules are negligible, while the corresponding aromatized compounds formed upon oxidation show moderate to high native fluorescence, depending on their structures. The fluorescence signal is quickly developed in the presence of trace amounts of the probe and the analytes in acetonitrile media at room temperature, with good analytical figures. ROS detection in aqueous media required incubation at 37 °C in the presence of horseradish peroxidase, and was applied to glucose quantitation by coupling glucose oxidation by O2 to fluorescence detection of H2O2. The mild reaction conditions and sensitive fluorescent response lead us to propose dihydroterphenyls with an embedded anthranilate moiety as chemosensors/chemodosimeters for ROS detection.

Synthesis and Photophysical Properties of 3-(Trifluoromethyl)-2H-imidazo[5,1-a]isoquinolinium Chloride Derivatives

Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 296-300 ◽  
Author(s):  
Ali Darehkordi ◽  
Fariba Rahmani ◽  
Mahin Ramezani ◽  
Alireza Bazmandegan-Shamili
Keyword(s):  
Blue Light ◽  
Uv Radiation ◽  
Photophysical Properties ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Light Emitting ◽  
Fluorescence Studies ◽  
Fluorescence Quantum Yields ◽  
Fluorescent Molecular Probes ◽  
Stokes Shifts

A series of novel blue-light-emitting 2H-imidazo[5,1-a]isoquinolinium chloride derivatives were synthesized by the reaction of isoquinoline with trifluoroacetimidoyl chlorides and isocyanides in dry CH2Cl2 in excellent yields. Fluorescence studies showed that the compounds absorb UV radiation and then emit blue light at about 481 nm with moderate to good fluorescence quantum yields. These compounds also showed high Stokes shifts, and can be used to develop ­ultrasensitive fluorescent molecular probes to study a variety of biological events and processes.

scholarly journals A Convenient Synthesis of Diketopyrrolopyrrole Dyes

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4758
Author(s):  
Vitor A. S. Almodôvar ◽  
Augusto C. Tomé
Keyword(s):  
High Performance ◽  
Coupling Reaction ◽  
Quantum Yields ◽  
Reaction Conditions ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Convenient Synthesis ◽  
Organic Optoelectronic ◽  
High Fluorescence ◽  
Stokes Shifts

Diketopyrrolo[3,4-c]pyrroles (DPP) are high-performance organic optoelectronic materials. They have applications in solar cells, fluorescent probes, bioimaging, photodynamic/photothermal therapy, and in many other areas. This article reports a convenient two-step synthesis of various DPP dyes from Pigment Red 254, an inexpensive commercial pigment. The synthesis includes a Suzuki–Miyaura cross-coupling reaction of a bis(4-chlorophenyl)DPP derivative with aryl and hetaryl boronic acids under mild reaction conditions. The new dyes show large Stokes shifts and high fluorescence quantum yields, important features for their potential use in technical and biological applications.

scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽  
2021 ◽  
Author(s):  
Xianglong Chu ◽  
Yadi Niu ◽  
Chen Ma ◽  
Xiaodong Wang ◽  
Yunliang Lin ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Color Tunable ◽  
Palladium Catalyzed ◽  
Structure Relationship ◽  
High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

scholarly journals Biocompatible Ir(III) Complexes as Oxygen Sensors for Phosphorescence Lifetime Imaging

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2898
Author(s):  
Ilya S. Kritchenkov ◽  
Anastasia I. Solomatina ◽  
Daria O. Kozina ◽  
Vitaly V. Porsev ◽  
Victor V. Sokolov ◽  
...  
Keyword(s):  
Near Infrared ◽  
Biological Systems ◽  
Aqueous Media ◽  
Oxygen Sensors ◽  
Quantum Yields ◽  
Complete Agreement ◽  
Phosphorescence Lifetime ◽  
Lifetime Imaging ◽  
Nir Emission ◽  
Phosphorescence Lifetime Imaging

Synthesis of biocompatible near infrared phosphorescent complexes and their application in bioimaging as triplet oxygen sensors in live systems are still challenging areas of organometallic chemistry. We have designed and synthetized four novel iridium [Ir(N^C)2(N^N)]+ complexes (N^C–benzothienyl-phenanthridine based cyclometalated ligand; N^N–pyridin-phenanthroimidazol diimine chelate), decorated with oligo(ethylene glycol) groups to impart these emitters’ solubility in aqueous media, biocompatibility, and to shield them from interaction with bio-environment. These substances were fully characterized using NMR spectroscopy and ESI mass-spectrometry. The complexes exhibited excitation close to the biological “window of transparency”, NIR emission at 730 nm, and quantum yields up to 12% in water. The compounds with higher degree of the chromophore shielding possess low toxicity, bleaching stability, absence of sensitivity to variations of pH, serum, and complex concentrations. The properties of these probes as oxygen sensors for biological systems have been studied by using phosphorescence lifetime imaging experiments in different cell cultures. The results showed essential lifetime response onto variations in oxygen concentration (2.0–2.3 μs under normoxia and 2.8–3.0 μs under hypoxia conditions) in complete agreement with the calibration curves obtained “in cuvette”. The data obtained indicate that these emitters can be used as semi-quantitative oxygen sensors in biological systems.

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.

Impact of cyclic topology: odd–even glass transition temperatures and fluorescence quantum yields in molecularly-defined macrocycles

2017 ◽  
Vol 8 (17) ◽  
pp. 2686-2692 ◽  
Author(s):  
Kun Li ◽  
Ganquan Jiang ◽  
Feng Zhou ◽  
Lishan Li ◽  
Zhengbiao Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Intermolecular Interactions ◽  
Topological Structure ◽  
Quantum Yields ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Fluorescence Quantum Yields

The topological structure of cyclic-TPEn+1 (n = 1–6) induces odd–even effects on the Tg and AIE behavior, arising from the alternation of intermolecular interactions.

Steric Effects in the Electronic Spectra of the 3,5-Diarylaminobenzene Derivatives

1986 ◽  
Vol 41 (11) ◽  
pp. 1311-1314 ◽  
Author(s):  
A. Balter ◽  
W. Nowak ◽  
P. Milart ◽  
J. Sepioł
Keyword(s):  
Excited State ◽  
Electronic Spectra ◽  
Fluorescence Properties ◽  
Steric Effects ◽  
Quantum Yields ◽  
Spectroscopic Behaviour ◽  
Fluorescence Quantum Yields ◽  
Excited State Lifetimes ◽  
Methyl Phenyl

Absorption and fluorescence properties, excited state lifetimes and fluorescence quantum yields were determined for a series of 3,5-diarylaminobenzene derivatives in solvents of different polarities. The role of the nitrile, methyl, phenyl and naphthyl substituents is discussed. Especially the steric effects on the spectroscopic behaviour of the investigated molecules are studied.

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