排序方式: 共有62条查询结果,搜索用时 15 毫秒
21.
Gondek E Całus S Danel A Kityk AV 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,69(1):22-26
A series of methoxy (MO) and carboethoxy (CE) derivatives of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline ([DPPQ]) are characterized by spectroscopic methods. All dyes show the photoluminescent spectra which are highly solvatochromic. In the case of 6MO[DPPQ] and 6CE[DPPQ] the emission bands are broad and shifted to the red with increasing of solvent polarity whereas the dyes 6MO1pMO[DPPQ] and 6MO13pMO[DPPQ] exhibit a reverse solvatochromism. The large difference between the excited- and state-dipole moments indicates a strong electron transfer effects in all dyes. The EL spectra are obtained for the fabricated OLEDs with a general structure of EL device ITO/PVK:6X[DPPQ]/Ca/Al. The blue emission originating from PVK host matrix appears to be quenched in EL spectra of doped PVK matrix giving rise to emission in blue, blue-green or green spectral regions. The obtained results demonstrate that a series of newly synthesized methoxy and carboethoxy [DPPQ]-derivatives may be considered as promising materials for electroluminescent applications. 相似文献
22.
Fabien Havas Nadine Leygue Mathieu Danel Béatrice Mestre Chantal Galaup Claude Picard 《Tetrahedron》2009,65(36):7673-4999
We describe an efficient and scalable synthesis of 4-carbomethoxy-6,6′-dimethyl-2,2′-bipyridine starting from easily available substituted 2-halopyridines and based on the application of modified Negishi cross-coupling conditions. This compound is a versatile starting material for the synthesis of 4-functionalized 2,2′-bipyridines bearing halide, alcohol, amine, and other functionalities, suitable for conjugation to biological material (2a-c, 3a-g). The utility of this compound in the construction of more complex architectures was further demonstrated by the synthesis of two bifunctional lanthanide chelators; an open chain ligand based on one 2,2′-bipyridine unit and a cryptand based on three 2,2′-bipyridine units [N2(bpy)3COOMe]. In the field of luminophoric biolabels, the photophysical properties of the corresponding Eu(III) cryptate are reported. 相似文献
23.
Andrzej Danel Ewa Gondek Mateusz Kucharek Pawe Szlachcic Arkadiusz Gut 《Molecules (Basel, Switzerland)》2022,27(9)
This paper summarises a little over 100 years of research on the synthesis and the photophysical and biological properties of 1H-pyrazolo[3,4-b]quinolines that was published in the years 1911–2021. The main methods of synthesis are described, which include Friedländer condensation, synthesis from anthranilic acid derivatives, multicomponent synthesis and others. The use of this class of compounds as potential fluorescent sensors and biologically active compounds is shown. This review intends to summarize the abovementioned aspects of 1H-pyrazolo[3,4-b]quinoline chemistry. Some of the results that are presented in this publication come from the laboratories of the authors of this review. 相似文献
24.
Tameev A. R. He Z. Milburn G. H. W. Danel A. Tomasik P. Vannikov A. V. 《Russian Journal of Electrochemistry》2004,40(3):359-363
Drift mobility of electrons in copolymers containing pyrazolyl fragment in the main or side chain of the copolymer is studied experimentally using the time-of-flight method. The mobility is an exponential function of the applied electric field, and its values for the copolymers range from 5 × 10–7 to 2 × 10–5 cm2 V–1 s–1 at the field strength ranging from 5 × 104 to 1 × 106 V cm–1. Based on the measured mobilities and the molecule parameters, which were obtained by a PM3 quantum-chemical calculation, the role of copolymer fragments in the transport of charge carriers is discussed. 相似文献
25.
Ahaidar A Fernández D Danelón G Cuevas C Manzanares I Albericio F Joule JA Alvarez M 《The Journal of organic chemistry》2003,68(26):10020-10029
Two alternative synthetic routes have been developed for the preparation of variolin B and deoxyvariolin B. The strategy is based on the preparation of the core tricyclic ring common to all variolins, pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine, followed by a palladium-catalyzed cross-coupling reaction to give the tetracyclic system. 相似文献
26.
Karl Rechthaler Krystyna Rotkiewicz Andrzej Danel Piotr Tomasik Karen Khatchatryan Gottfried Köhler 《Journal of fluorescence》1997,7(4):301-309
The fluorescence properties of several pyrazoloquinoline derivatives were performed by stationary as well as by time-resolved spectrosopy. Non-donor-substituted compounds show a high quantum yield; transition dipole moments of absorption and fluorescence as well as experimental and calculated lifetimes are in excellent agreement. The donor-substituted compound DMA-DPPQ exhibits a charge transfer fluorescence in polar solvents. Additionally, dual fluorescence appears in polar protic solvents. The nature of the charge transfer state is discussed with respect to the the TICT model. 相似文献
27.
Zuo La Cécile Danel Gaëlle Grolaux Julie Charton Christophe Furman Emmanuelle Lipka 《Electrophoresis》2021,42(17-18):1810-1817
A capillary electrokinetic chromatography method (CEKC) was developed for complete stereoisomeric separation of a neutral, hydrophobic, multiple chiral center dihydropyridone analogue, a drug candidate proposed in type 2 diabetes treatment. A background electrolyte comprising three cyclodextrins was found to successfully separate the eight isomers. First an anionic cyclodextrin, the SBE-β-CD, was selected to allow the chiral separation of our neutral compound and partial resolutions of the eight isomers were obtained. Then, the effects of different parameters such as the nature and concentration of the other cyclodextrins added and pH of the buffer were examined. Finally, a triple CD-system consisted of 15 mM SBE-β-CD plus 15 mM γ-CD and 40 mM HP-γ-CD in a 50 mM borate background electrolyte at pH 10, was found to successfully separate the eight isomers. Last, the selectivity and limits of detection and quantification were evaluated for this optimized method. 相似文献
28.
Chemistry of Heterocyclic Compounds - An efficient Pd-catalyzed C–N bond formation for the synthesis of different pyrazole derivatives using XPhos as a ligand and KOH as a base is presented.... 相似文献
29.
Gasiorski P Danel KS Matusiewicz M Uchacz T Kuźnik W Kityk AV 《Journal of fluorescence》2012,22(1):81-91
Paper reports the DFT/TDDFT study on the electronic structure and spectral properties of the five-membered annulated diphenyl
azafluoranthene derivative 1,3-diphenyl-3H-indeno[1,2,3-de]pyrazolo[3,4-b]quinoline (DPIPQ) by means of polarizable continuum model (PCM) and Onsager reaction field approaches at the B3LYP/6-31+G(d,p)
level of theory. The results of calculations are compared with the optical absorption and fluorescence spectra as well as
with the cyclic voltammetry data. The DFT/TDDFT/PCM approaches exhibit rather good quantitative agreement regarding the spectral
position of the first absorption band; the discrepancy between the experiment and theory is less than 0.06 eV (linear response
approach) or 0.25 eV (state specific approach). As for the fluorescence emission the TDDFT/PCM calculations underestimate
the transition energy on about of 0.7–0.8 eV. Such discrepancy should be attributed to insufficient quality of the TDDFT/PCM
optimization in the excited state. Ignoring the geometrical relaxation in the excited state provides considerably better agreement
between the experiment and theory; discrepancy is less than 0.1–0.22 eV depending on a solvent polarity. The dominant influence
on the fluorescence emission results mainly from the solvent reorganization in the excited state whereas the solute relaxation
is indeed weak and may be ignored. 相似文献
30.
Paper deals with the experimental investigations and quantum chemical calculations of the absorption spectra of newly synthesized 1,3-diphenyl-1H-Pyrazolo[3,4-b]quinoline and its 6-Vinyl, 6-N,N-Diphenyl, 6-Methyl, 6-Fluoro, 6-Bromo, and 6-Chloro derivatives. The calculations are performed by means of the semiempirical quantum chemical methods AM1 or PM3 combined with: (a) equilibrium molecular conformation (EMC) in vacuo; (b) the molecular conformation model considering a dynamical rotation of phenyl rings only (T = 300 K); and (c) the most general model of the conformational molecular dynamics (MD) at T = 300 K. It is shown that the phenyl dynamics appears to be not important in the spectral position of absorption thresholds as well as in a broadening of most absorbtion bands. On the other hand, the MD simulations reproduce a broadening of the absorbtion spectra as well as the electron-vibronic coupling leading to a red-shift of absorption bands with increasing of temperature. The conformational MD model in combination with the quantum chemical AM1 method gives in most cases the best agreement with the experimental data, namely in the sense of spectral positions and width of the absorption bands including first oscillators (absorption thresholds). 相似文献