502846-08-4Relevant articles and documents
Spectroscopic investigation, photophysical parameters and DFT calculations of 4,4′-(1E,1′E)-2,2′-(pyrazine-2,5-diyl)bis(ethene-2,1-diyl)bis(N,N-dimethylaniline) (PENDA) in different solvents
Asiri, Abdullah M.,Alamry, Khalid A.,Pannipara, Mehboobali,Al-Sehemi, Abdullah G.,El-Daly, Samy A.
, p. 722 - 730 (2015)
A comprehensive investigation on the photophysics of a π-conjugated potential push-pull chromophore system 4,4′-(1E,1′E)-2,2′-(Pyrazine-2,5-diyl)bis(ethene-2,1-diyl)bis(N,N-dimethylaniline) (PENDA) has been carried out spectroscopically. The optical absorption and emission properties of this molecule have been studied in different solvents. The molecule PENDA shows strong solvatochromic emission upon changing the solvent polarity from nonpolar to polar; indicating that emission state is of intramolecular charge transfer (ICT) character. The solvent effect on the spectral properties such as singlet absorption, molar absorptivity, oscillator strength, dipole moment and fluorescence quantum yield of PENDA have been studied in detail. Lippert-Mataga and Reichardt correlations were used to estimate the difference between the excited and ground state dipole moments (Δμ). Ground and electronic excited states geometric optimizations were performed using density functional theory (DFT) and time-dependent density functional theory (TDDFT), respectively, with the Gaussian 09 package. A solution of (8 × 10-5 M) PENDA in THF, dioxane, CH3CN and CHCl3 gives laser emission when pumped by a nitrogen laser pulse (λex = 337.1 nm) of 800 ps duration and 1.48 mJ pulse energy. PENDA dye displays fluorescence quenching by colloidal silver nanoparticles (Ag NPs) in ethanol. The fluorescence data reveal that dynamic quenching and energy transfer play a major role in the fluorescence quenching mechanism.
Photophysical and TDDFT investigation for (E, E)-2, 5-bis [2-(4-(dimethylamino)phenyl) ethenyl]pyrazine (BDPEP) laser dye in restricted matrices
Abdel Gawad, Sayed A.,Abou Kana, Maram T. H.,Ebeid, El-Zeiny M.,El-Daly, Samy A.,Sakr, Mahmoud A. S.
, (2020/05/13)
The Photophysical parameters such as fluorescence quantum yield (Φf), oscillator strength (f), radiative decay rate constant (kr), change of dipole moment from ground to excited state (μ12), gain coefficient and lasing eff
COMPOUNDS FOR THE DIAGNOSIS OF NEURODEGENERATIVE DISORDERS ON THE OLFACTORY EPITHELIUM
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Paragraph 0194; 0195; 0196; 0197, (2013/11/06)
Subject of the present invention are compounds with high affinity for the Aβ protein, α-synuclein or for Tau-PHF aggregates, which are suitable as preferably fluorescent probes for the in vivo diagnosis of neurodegenerative disorders like e.g. Alzheimer's
Bis(arylvinyl)pyrazines, -pyrimidines, and -pyridazines As imaging agents for tau fibrils and β-Amyloid plaques in alzheimers disease models
Bolaender, Alexander,Kieser, Daniel,Voss, Constantin,Bauer, Silvia,Berger, Robert,Schmidt, Boris,Schoen, Christian,Burgold, Steffen,Bittner, Tobias,Herms, Jochen,Hoelzer, Jana,Hilger, Ingrid,Heyny-Von Haussen, Roland,Mall, Gerhard,Goetschy, Valerie,Czech, Christian,Knust, Henner
, p. 9170 - 9180,11 (2020/10/15)
The in vivo diagnosis of Alzheimers disease (AD) is of high socioeconomic interest and remains a demanding field of research. The biopathological hallmarks of the disease are extracellular plaques consisting of aggregated β-amyloid peptides (Aβ) and tau protein derived intracellular tangles. Here we report the synthesis and evaluation of fluorescent pyrazine, pyrimidine,and pyridazine derivatives in vitro and in vivo aiming at a tau-based diagnosis of AD. The probes were pre-evaluated on human brain tissue by fluorescence microscopy and were found to label all known disease-related alterations at high contrast and specificity. To quantify the binding affinity, a new thiazine red displacement assay was developed and selected candidates were toxicologically profiled. The application in transgenic mouse models demonstrated bioavailability and brain permeability for one compound. In the course of histological testing, we discovered an AD-related deposition of tau aggregates in the Bowmans glands of the olfactory epithelium, which holds potential for an endoscopic diagnosis of AD in the olfactory system.
