- A stimuli-responsive supramolecular assembly between inverted cucurbit[7]uril and hemicyanine dye
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The effect of inverted curcurbit[7]uril (iQ[7]) on the binding mode of 2-(4-(dimethylamino)styryl)-1-methylpyridinium (DASPMI) was determined in this study. A large fluorescence enhancement of DASPMI was realized by the formation of an inclusion complex with iQ[7]. A 1:1 inclusion complex was determined through UV absorption and fluorescence spectroscopies, 1H nuclear magnetic resonance (NMR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and isothermal titration calorimetry (ITC) at different pH values. In addition, we also devised a method for the controlled release of DASPMI from the iQ[7] macrocycle by adding α,α′-diamino-p-xylene.
- Gao, Zhong-Zheng,Kan, Jinglan,Tao, Zhu,Bian, Bing,Xiao, Xin
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p. 15420 - 15426
(2018/09/29)
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- Solvation studies of some tailor made α-N,N-dimethylaminostyryl-N-alkyl pyridinium dyes in binary solvent mixtures containing alcohols, hexane, 1,4-dioxane, DCM and acetone
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Solvation of some α-N,N-dimethylaminostyryl-N-alkyl pyridinium dyes has been studied in binary solvent mixtures of alcohol-hexane, alcohol-1,4-dioxane, acetone-hexane, acetone-1,4-dioxane, DCM-hexane, DCM-1,4-dioxane and 1,4-dioxane-hexane to analyze the preferential solvation of any of the solvent in the binary mixture. Due to solvent-solvent interaction, hyper and hypo-polarity in the solvent complex is observed, which is reflected from the bathochromic and hypsochromic shifts of the absorption maxima of the dye molecules. The solvent cage around the dye is influenced by polar-polar and apolar-apolar interactions as well as a proper balance between both the types of interactions.
- Tripathy, Sarita,Dash, Sukalyan
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- Intramolecular charge transfer of push-pull pyridinium salts in the singlet manifold
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The solvent effect on the photophysical and photochemical properties of the iodides of three trans (E) isomers of 2-D-vinyl,1-methylpyridinium, where D is a donor group (4-dimethylaminophenyl, 3,4,5-trimethoxyphenyl and 1-pyrenyl), was studied by stationary and transient absorption techniques. The results obtained allowed the negative solvatochromism and relaxation pathways of the excited states in the singlet manifold to be reasonably interpreted. Resorting to ultrafast absorption techniques and DFT calculations allowed information on the excited state dynamics and the role of the solvent-controlled intramolecular charge transfer (ICT) processes to be obtained. The structure-dependent excited state dynamics in nonpolar solvents, where the ICT is slower than solvent rearrangement, and in polar solvents, where an opposite situation is operative, was thus explained. The push-pull character of the three compounds, particularly the anilino-derivative, suggests their potential application in optoelectronics.
- Carlotti, Benedetta,Consiglio, Giuseppe,Elisei, Fausto,Fortuna, Cosimo G.,Mazzucato, Ugo,Spalletti, Anna
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p. 3580 - 3592
(2014/06/09)
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- Solvent-free condensation of methyl pyridinium and quinolinium salts with aldehydes catalyzed by DBU
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Methylpyridinium and methylquinolinium salts were condensed under solvent-free conditions with aromatic aldehydes in the presence of 1,8-diazabicyclo[5.4.]undec-7-ene (DBU) as catalyst, by grinding at room temperature. The products are dyes or useful intermediates. The DBU can be easily recycled and reused. Taylor & Francis Group, LLC.
- Seiad, Linda Loucif,Villemin, Didier,Bar, Nathalie,Hachemi, Messaoud
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experimental part
p. 650 - 657
(2011/12/21)
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- Synthesis, structure and in vitro antibacterial activities of new hybrid disinfectants quaternary ammonium compounds: Pyridinium and quinolinium stilbene benzenesulfonates
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The series of pyridinium (1-10) and quinolinium (11-20) stilbene benzenesulfonates have been synthesized and their structures were investigated by UV-vis, FT-IR and 1H NMR spectroscopy. In addition, compound 5 was also determined by single crystal X-ray diffraction technique. The antibacterial activity of the synthesized compounds against both Gram-positive and Gram-negative bacteria has been determined. The quinolinium derivatives exhibited two very potent characteristic activities, namely, (i) specific activity to Methicillin-Resistant Staphylococcus aureus and (ii) with broad band spectrum activity. Compounds 11, 13 and 14 are the most active showing broad spectrum antibacterial activity against Gram-positive (Methicillin-Resistant S. aureus, S. aureus, Bacillus subtilis, Vancomycin-Resistant Enterococcus faecalis and E. faecalis) and Gram-negative bacterium (Shigella sonnei). The MICs of these compounds were found to be better than that of Benzalkonium chloride (BZK), the commercially used disinfectant. The new pyridinium and quinolinium stilbene benzenesulfonates have been synthesized and characterized. All compounds were evaluated for their antibacterial activity against the tested Gram-positive and Gram-negative bacteria using colorimetric assay.
- Chanawanno, Kullapa,Chantrapromma, Suchada,Anantapong, Theerasak,Kanjana-Opas, Akkharawit,Fun, Hoong-Kun
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experimental part
p. 4199 - 4208
(2010/09/16)
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- X-ray and DFT studies of the structure and spectral property of 2-[2-(4-dimethylaminophenyl)ethenyl]-1-methyl-pyridinium iodide
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A hemicyanine dye: 2-[2-(4-dimethylaminophenyl)ethenyl]-1-methyl-pyridinium iodide (1) was synthesized and characterized by X-ray diffraction, 1H NMR, MS, IR, UV-Vis spectra and elemental analysis. The crystals are monoclinic, space group P21/c, with a = 7.1231(8), b = 20.672(2), c = 10.9642(12) ?, V = 1605.7(3) ?3, and Z = 4 (at 298(2) K). Crystal stacking scheme indicates the hydrogen bonds and intermolecular π?π interactions; the molecular planes arrange in a head-to-tail fashion along the ab plane due to the strong 'push-pull' electron system. Molecular geometries, frequencies and absorption properties were calculated at DFT/TD-DFT level using two hybrid exchange-correlation functionals, B3LYP and PBE1PBE. These calculations on (1) provide deep insight into its electronic structure and property.
- Zhang,Wang,Zhai,Wen,Zhang
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p. 117 - 122
(2008/12/20)
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- Combinatorial approach to organelle-targeted fluorescent library based on the styryl scaffold
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The first fluorescent styryl dye library with a broad color range was synthesized by combinatorial condensation of various aldehydes and methyl pyridinium compounds, and their applications as organelle specific staining probes were demonstrated. Copyright
- Rosania, Gustavo R.,Lee, Jae Wook,Ding, Liang,Yoon, Hai-Shin,Chang, Young-Tae
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p. 1130 - 1131
(2007/10/03)
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- Development of fluorescence probes based on stilbazolium salts for monitoring free radical polymerization processes
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A series of 1-methyl-2-(4-aminostyryl)pyridinium perchlorates and iodides were investigated as fluorescent probes for the monitoring of the progress of free radical polymerization. The study on the changes in the fluorescence intensity and spectroscopic shifts of studied compounds were carried out during thermally initiated polymerization of methyl methacrylate and during photoinitiated polymerization of a 2-ethyl-2-(hydroxymethyl)propane-1,3-diol triacrylate (TMPTA)-1-methylpyrrolidin-2-one (MP) mixture. The purpose of these studies was to find a relationship between the changes in the shape and intensity of probe fluorescence and degree of monomer conversion into polymer. The polymer formation was estimated gravimetrically or by the measurement of the degree of monomer double bond disappearance using FTIR spectroscopy.
- Wroblewski, Stanislaw,Trzebiatowska, Katarzyna,Jedrzejewska, Beata,Pietrzak, Marek,Gawinecki, Ryszard,Paczkowski, Jerzy
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p. 1909 - 1917
(2007/10/03)
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- Molecular Association of Water-Soluble Calixarenes with Several Stilbene Dyes and Its Application to the Facile Determination of Cationic Surfactant Concentrations
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The molecular association of water-soluble p-sulfonatocalix[n]arenes (1n; n = 4, 6, and 8) with several stilbene dyes (D) has been studied by spectrophotometric and 1HNMR methods. It was found that 1n reacts in 1: 1 stoichiometry with, D such as 4-[(4-dimethylamino)styryl]-1-methylpyridinium (St-4Me), 2-[(4-dimethylamino)styryl]-1-methylpyridinium (St-2Me) and 2-[(4-dimethylamino)styryl]-1-ethylpyridinium (St-2Et) iodides to form their complexes (1nD). The apparent association constants for 18-complexes are larger by about ten times than those of 14- and 16-complexes. Examinations of the CPK molecular models and the spectrophotometric studies suggested that 14 complexes D mainly with its 1-methyl- or 1-ethylpyridinium group, whereas 16 complexes D either with its pyridinium ring or with its protonated dimethylamino group in a similar probability, and in 18-complexes the molecule is wholly incorporated into the cavity of 18. The absorbance of D, which was decreased by association with 1n, was regenerated by the addition of other colorless cationic surfactants (A) such as cetylethyldimethylammonium ion. Studies on the substitution reaction of 1nD with A indicated that a 1 : 1 complex (1nA) is formed by releasing a free dye molecule (D). This was applied to a convenient determination of the cationic surfactant concentration in water.
- Nishida, Masashi,Ishii, Daido,Yoshida, Isao,Shinkai, Seiji
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p. 2131 - 2140
(2007/10/03)
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- Interaction of Solvent with the Ground and Excited State of 2- and 4--1-alkylpyridinium Iodides: an Absorption and Fluorescence study
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The absorption and emission characteristics of four organic salts: 4--1-alkylpiridinium iodides 1-3 (alkyl: 1 = methyl, 2 = ethyl, 3 = isopropyl) and 2--1-methylpiridinium iodide 4, in various solvents have been studied.It was found that these salts emit a single emission band which is dependent on the solvent's hydrogen bonding and polarity.In polar solvents a marked hypsochromic shift in absorption was observed, while no solvatochromism was observed in the emission spectra.A mechanism is proposed to explain these observations.In the salts 1-3 alkyl substitution on the pyridinium ring d oes not produce significant changes in their spectral properties.Acceptable correlations were obtained for the singlet excitation energies with the redox-potential differences of dyes 1-4. - Keywords: Absorption; emission; hydrogen-bonding; solvatochromism; redox-potential.
- Al-Ansari, Ibrahim Az
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p. 593 - 600
(2007/10/03)
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- Synthesis and Characterization of Mono-, Bis-, and Trissubstituted Pyridinium and Pyrylium Dyes
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A series of mono-, bis-, and trissubstituted pyridinium and pyrylium dyes have been synthesized by the condensation of methylpyridinium and methylpyrylium salts with aldehydes or nitroso compound.Large bathochromic shifts were observed in the following order, both in substituted azomethine pyridinium and pyrylium dyes, monobistris.The magnitude of the shift appeared in the order of multiple bonds, -CH=CH- -CH=CH- CH=CH- -CH=N-.
- Matsui, Masaki,Kawamura, Shigeo,Shibata, Katsuyoshi,Muramatsu, Hiroshige
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