Substituent effects on fluorescence properties of thiazolo[4,5-b]pyrazine derivatives

2014 ◽  
Vol 13 (12) ◽  
pp. 1765-1772 ◽  
Author(s):  
Tatsuki Nakagawa ◽  
Minoru Yamaji ◽  
Shojiro Maki ◽  
Haruki Niwa ◽  
Takashi Hirano
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Fluorescence Yield ◽  
Fluorescence Properties ◽  
Electron Donating Groups ◽  
Phenyl Moiety

A study of fluorescence properties of thiazolo[4,5-b]pyrazine derivatives with the phenyl group at C2, prepared from amidopyrazines. The introduction of electron-donating groups onto the 2-phenyl moiety increases the fluorescence yield and appearance of solvatochromic character.

Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Wave Number ◽  
Vibrational Coupling ◽  
Wave Numbers ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
The Relationship ◽  
Derivatives Of ◽  
Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

scholarly journals Bicyclic 1,3a,6a-Triazapentalene Chromophores: Synthesis, Spectroscopy and Their Use as Fluorescent Sensors and Probes

Chemosensors ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Yingchun Wang ◽  
Tomas Opsomer ◽  
Wim Dehaen
Keyword(s):  
Stokes Shift ◽  
Substituent Effects ◽  
Visible Spectrum ◽  
Fluorescent Sensors ◽  
Biological Imaging ◽  
Fluorescent Imaging ◽  
Fluorescence Properties ◽  
Imaging Probes ◽  
Synthetic Methodologies ◽  
Aromatic Heterocyclic

The 1,3a,6a-triazapentalene (TAP) is an aromatic heterocyclic fluorescent dye with interesting features such as its small size, large Stokes shift, solvatochromism, and emission wavelengths that are spread across the visible spectrum. TAPs have been synthesized via different synthetic strategies involving click−cyclization−aromatization domino reactions, gold-catalyzed cyclization of propargyl triazoles or triazolization of acetophenones. As a result, TAPs with diverse substitution patterns were obtained, showing varying fluorescence properties. Based on these properties, several TAPs have been selected and studied as fluorescent imaging probes in living cells and as sensors. This mini review provides an overview of the research on the bicyclic TAPs and does not comment on the literature about benzo or otherwise fused systems. The synthetic methodologies for the preparation of TAPs, the substituent effects on the fluorescence properties, and the behavior of the TAP core as an element of biological imaging probes and sensors are discussed.

Substituent effects on the electronic spectra of aromatic hydrocarbons I. A comparison of the localized-orbital and iso-conjugate-hydrocarbon models for interpreting the spectra of amino- and nitrobenzenes

1964 ◽  
Vol 278 (1372) ◽  
pp. 57-63 ◽  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Configuration Interaction ◽  
Electronic Spectra ◽  
Substituent Effects ◽  
Phenyl Group ◽  
Zero Order ◽  
Wave Functions ◽  
Localized Orbital

Two models are used to analyze the spectra of aniline and nitrobenzene. These are the localized-orbital model, in which there is no delocalization of the electrons between the phenyl group and the substituent, and the iso-conjugate-hydrocarbon model, in which there is complete delocalization. Neither model is very satisfactory with zero-order wave functions and energies. Both give a satisfactory interpretation of the spectra if configuration interaction is taken into account but the localized-orbital model is rather better for calculating energies. The localized-orbital model is also more readily applied to polysubstituted benzenes.

Substituent Effects on the Absorption and Fluorescence Properties of Anthracene

2017 ◽  
Vol 121 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
Salsabil Abou-Hatab ◽  
Vincent A. Spata ◽  
Spiridoula Matsika
Keyword(s):  
Substituent Effects ◽  
Fluorescence Properties

2-Pyridone-based fluorophores containing 4-dialkylamino-phenyl group: Synthesis and fluorescence properties in solutions and in solid state

2016 ◽  
Vol 124 ◽  
pp. 196-202 ◽  
Author(s):  
Masayori Hagimori ◽  
Yasuhiro Shigemitsu ◽  
Ryo Murakami ◽  
Kenichirou Yokota ◽  
Yasuhisa Nishimura ◽  
...  
Keyword(s):  
Solid State ◽  
Phenyl Group ◽  
Fluorescence Properties

Réduction catalytique de cétones α,β-éthyléniques à température modérée par

1979 ◽  
Vol 57 (2) ◽  
pp. 218-221 ◽  
Author(s):  
D. Beaupere ◽  
P. Bauer ◽  
R. Uzan
Keyword(s):  
Electrochemical Reduction ◽  
Reduction Potential ◽  
Initial Rate ◽  
Substituent Effects ◽  
Hydrogenation Reaction ◽  
Unsaturated Ketones ◽  
Hydride Ion ◽  
Inverse Effect ◽  
Electron Donating Groups

The use of the catalyst [Formula: see text] in the reduction of the ethylenic system of styryl ketones by 1-phenylethanol permits the hydrogenation reaction to proceed at 50 °C. Some substituent effects in the α,β-unsaturated ketones were demonstrated at this temperature. These showed an increase in the initial rate of reduction for electron-attracting groups and the inverse effect for electron-donating groups. The observation of a relation between the electrochemical reduction potential of these ketones and their rate of hydrogenation suggests a transfer of hydrogen to the ketone by a hydride ion intermediate. [Journal translation]

An Investigation of Substituent Effects on Coupling Constants to Vinyl Protons in Styrene Derivatives

1974 ◽  
Vol 52 (19) ◽  
pp. 3415-3423 ◽  
Author(s):  
William F. Reynolds ◽  
Ian R. Peat ◽  
Gordon K. Hamer
Keyword(s):  
Long Range ◽  
Substituent Effects ◽  
Phenyl Group ◽  
Coupling Constants ◽  
Vinyl Proton ◽  
Model Compounds ◽  
Proton Coupling ◽  
Phenyl Proton ◽  
Styrene Derivatives ◽  
Induced Changes

Experimental long-range phenyl proton–vinyl proton coupling constants in 4-substituted styrenes are substituent independent. This is also predicted by INDO–finite perturbation theory calculations of these coupling constants. Comparison with calculated and experimental long-range coupling constants for 4-substituted benzaldehydes suggests that the previously reported substituent dependence for the latter coupling constants arises from substituent-induced changes in molecular geometry.Geminal vinyl coupling constants in 4-substituted styrenes, α-methylstyrenes, and α-t-butylstyrenes are substituent dependent with substituent effects increasing as phenyl and vinyl groups are twisted out of planarity. These trends are reproduced by INDO–FPT calculations. It is concluded that the substituent effects are primarily transmitted through space.Both experimental and calculated vinyl 13C–1H coupling constants show strong stereospecific substituent effects. From the pattern of results (particularly the greater field dependence for JC(β)H(9) than JC β)H(8)) it is concluded that these coupling constants.also reflect through-space substituent effects. This is supported by calculations on model compounds with no intervening phenyl group.

Fluorescence Properties of Diphenylthiazolo[4,5-b]pyrazines Tuned by Donor-Acceptor Substituent Effects

2015 ◽  
Vol 91 (4) ◽  
pp. 807-813 ◽  
Author(s):  
Tatsuki Nakagawa ◽  
Minoru Yamaji ◽  
Shojiro Maki ◽  
Haruki Niwa ◽  
Takashi Hirano
Keyword(s):  
Substituent Effects ◽  
Fluorescence Properties ◽  
Acceptor Substituent ◽  
Donor Acceptor

Solvent and substituent effects on UV-vis spectra and redox properties of zinc p-hydroxylphenylporphyrins

2017 ◽  
Vol 21 (07n08) ◽  
pp. 465-475 ◽  
Author(s):  
Guifen Lu ◽  
Xiaoqin Jiang ◽  
Zhongping Ou ◽  
Sen Yan ◽  
Karl M. Kadish
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Nonaqueous Solvents ◽  
Donor Number ◽  
Redox Potentials ◽  
The Third ◽  
Visible Spectra ◽  
Phenyl Rings ◽  
Substituent Constants ◽  
Uv Visible

A series of zinc[Formula: see text]-hydroxylphenylporphyrins was synthesized and characterized by spectroscopic and electrochemical methods in four different nonaqueous solvents. The investigated compounds are represented as [([Formula: see text]-HOPh)[Formula: see text](ptBuPh)[Formula: see text]P]Zn, where P represents the dianion of a porphyrin, Ph represents a phenyl group, HO and [Formula: see text]Bu are para substituents on the meso-phenyl rings of the macrocycle and [Formula: see text] = 0–4. The four utilized nonaqueous solvents were dichloromethane (CH[Formula: see text]Cl[Formula: see text], NN-dimethylformamide (DMF), dimethylsulfoxide (DMSO) and pyridine (Py) which were selected on the basis of their coordinating capabilities. The UV-visible spectra and redox potentials of each porphyrin were analyzed both as a function of Hammett substituent constants for groups at the para-positions of the meso-phenyl rings and as a function of the Gutmann solvent donor number which is related to the coordinating ability of the solvent. Each porphyrin exhibits two reductions in CH[Formula: see text]Cl[Formula: see text], DMSO and Py while three reductions are observed in DMF, the additional reaction being due to a phlorin product generated in solution after formation of the porphyrin dianion. Two or three reversible oxidations were seen in CH[Formula: see text]Cl[Formula: see text], the exact number depending upon the specific porphyrin and the presence of [Formula: see text]-OH substituents at the meso-phenyl rings of the compound. The first two oxidations were assigned as involving the conjugated macrocycle and the third is associated with oxidation of the meso-HOPh group(s).

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