scholarly journals Fluorimetric Properties of 3-Aminoflavone Biomolecule (3-AF). X-ray Crystal Structure of New Polymorph of 3-AF

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2927 ◽  
Author(s):  
Wojciech Pająk ◽  
Małgorzata Fabijańska ◽  
Jakub Wojciechowski ◽  
Wojciech M. Wolf ◽  
Anna Kilanowicz ◽  
...  

The crystal structure of the new polymorphic form of 3-aminoflavone (3-AF) has been determined by single crystal X-ray diffraction. This report presents results of fluorimetric studies on 3-AF in methanol and aquatic solvents. Based on 3D fluorescence emission spectra, optimal values for excitation (λex) and emission/analytical (λem) wavelength, the analytical concentration range as well as the range of concentration quenching for the studied compound were established. Moreover, the limit of detection (LOD) and the limit of quantification (LOQ) were determined. The results were compared with those obtained using the standard UV-Vis absorption spectrophotometric method. The effect of acidity (pH) and the concentration of halide anions (chlorides, bromides, iodides and fluorides) on fluorescence quenching were analysed.

2015 ◽  
Vol 18 (3) ◽  
pp. 155-158 ◽  
Author(s):  
Yuan Zhou ◽  
Qiming Liu ◽  
Yuao Zhang

Two new zinc(II) complexes have been prepared by reaction of 2-(2’-Hydroxyphenyl)-2-oxazoline(Hoz) with Zn(acac)2 and ZnCl2 respectively. The complexes are characterized by IR and X-ray crystallography. Complex 1 is dinuclear zinc structure bridged by the oxygen atoms from oz- ligand and acac- ligand as terminal chelating ligand. Complex 2 is tetranuclear zinc structure bridged by both μ2-oxygen from oz- ligand and μ3-methoxide. 1 crystalizes in P21 space group with crystallographic parameters: a=9.3842Å19), b=13.5840 Å30), c=11.1380 Å20), β=96.250°(30). 2 crystalizes in P-1 space group with crystallographic parameters: a=9.5517Å(19), b=11.1234Å(22), c=11.1826Å(22), α=102.820°(30), β=114.988°(30), γ=100.806°(30). The UV absorption and fluorescence emission spectra are measured on the methanol solution and solid state of complex 1 and it shows strong luminescence.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Guangjie He ◽  
Nana Ma ◽  
Linlin Li ◽  
Chenyan Xie ◽  
Linlin Yang ◽  
...  

A new fluorescence probe L was rationally designed and synthesized for the recognition of Cu2+ ions by the combination of coumarin hydrazide and 2-acetylpyrazine. The photochemical properties and selectivity of L for Cu2+ ions in a CH3CN/HEPES (3 : 2, v/v) buffer were investigated by UV-vis absorption and fluorescence emission spectra. A highly selective and sensitive response of L for Cu2+ ions over other competing metal ions was observed with limit of detection in 3 μM. The coordination stoichiometry of L to Cu2+ ions was determined to be 1 : 1 by the UV-vis absorption spectrum, the fluorescence titrations, and density functional theory (DFT) calculations. Moreover, L was applied successfully for recognition of intracellular Cu2+ ions in living cells.


2019 ◽  
Vol 75 (5) ◽  
pp. 504-507 ◽  
Author(s):  
Hui-Ru Chen

Excellent fluorescence properties are exhibited by d 10 metal compounds. The novel three-dimensional ZnII coordination framework, poly[[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl] ether-κ2 N 3:N 3′}(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)zinc(II)] 1.76-hydrate], {[Zn(C6H2O5)(C20H18N4O)]·1.76H2O} n , has been prepared and characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis revealed that the compound exhibits a novel fourfold interpenetrating diamond-like network. This polymer also displays a strong fluorescence emission in the solid state at room temperature.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1831
Author(s):  
Hsin Lee ◽  
Yen-Chang Su ◽  
Hsiang-Hao Tang ◽  
Yu-Sheng Lee ◽  
Jan-Yee Lee ◽  
...  

Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.


2011 ◽  
Vol 65 (6) ◽  
Author(s):  
Thitipone Suwunwong ◽  
Suchada Chantrapromma ◽  
Hoong-Kun Fun

AbstractThree series of heteroaryl chalcones, (E)-1-(2-pyridyl)-3-(X)prop-2-en-1-one (Ia-Ic), (E)-1-(2-thienyl)-3-(X)prop-2-en-1-one (IIa-IIc), and (E)-1-(2-furyl)-3-(X)prop-2-en-1-one (IIIa-IIIc), where X = 2,4,5-trimethoxyphenyl (for series a), X = 2,4,6-trimethoxyphenyl (for series b), and X = 3,4,5-trimethoxyphenyl (for series c) were synthesised using basic catalysed aldol condensation and characterised using 1H NMR and FT-IR spectroscopies. Compound IIa was also characterised by single crystal X-ray analysis. The absorption and fluorescence emission spectra of these compounds revealed that the absorption and fluorescence depended on the heterocycle rings and trimethoxysubstituted phenyl rings linked to the enone system. The position of methoxy groups substantially affected the fluorescent properties. Compounds Ia-IIIa containing the 2,4,5-trimethoxyphenyl moiety exhibited the red-shift phenomenon and strong emission fluorescence.


2013 ◽  
Vol 864-867 ◽  
pp. 83-87
Author(s):  
Ling Liang Long ◽  
Yan Jun Wu ◽  
Lin Wang

A new fluorescent probe 1, bearing a pyridine group as receptor for H+and a coumarin dye as fluorophore, was synthesized and characterized by1H NMR,13C NMR, ESI-Ms and single crystal X-ray diffraction analysis. The probe exhibited fluorescence ratiometric response to acidic pH. With decreasing of the pH from 8.32 to 2.49, the fluorescence emission spectra exhibited large red shift from 541 to 631 nm, with the emission ratios (I541/I631) changed dramatically from 25.9 to 0.08, and the pKavalue was calculated to be 5.45. Probe 1 exhibited high selectivity to pH, other interference species including metal ions and amino acid exerted no visible effect on probe 1 detecting pH. The intracellular pH imaging applications proved that the probe is suitable for monitoring acidic pH fluctuations in living cells.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Guanglan Mao ◽  
Chenxi Liu ◽  
Nan Yang ◽  
Linlin Yang ◽  
Guangjie He

A novel fluorescence probe NA-LCX was rationally designed and synthesized for the sequential recognition of Cu2+ and H2S by the combination of hydroxyl-naphthalene and diformylphenol groups. The response properties of NA-LCX for Cu2+ ions and H2S with “on-off-on” manner were investigated by fluorescence emission spectra. A highly selective and sensitive response of complex NA-LCX-Cu2+ for H2S over other competing amino acids was observed with a limit of detection at 2.79 μM. The stoichiometry of NA-LCX toward Cu2+ ions was determined to be 1 : 1 by the UV-Vis absorption spectrum, and the coordination configuration was calculated by density functional theory (DFT) calculations. Moreover, probe NA-LCX was applied successfully for the recognition of Cu2+ ions and H2S in living cells.


2015 ◽  
Vol 71 (3) ◽  
pp. 195-198
Author(s):  
Ah-Rang Lee ◽  
Won-Sik Han

The crystal structure of the title bifunctional silicon-bridged compound, C35H31NSi, (I), has been determined. The compound crystallizes in the centrosymmetric space groupP21/c. In the crystal structure, the pairs of aryl rings in the two different chromophores,i.e.9-phenyl-9H-carbazole and 9,9-dimethyl-9H-fluorene, are positioned orthogonally. In the crystal packing, no classical hydrogen bonding is observed. UV–Vis absorption and fluorescence emission spectra show that the central Si atom successfully breaks the electronic conjugation between the two different chromophores, and this was further analysed by density functional theory (DFT) calculations.


2015 ◽  
Vol 71 (7) ◽  
pp. 598-601 ◽  
Author(s):  
Marek Daszkiewicz ◽  
Lubomir D. Gulay

Designing new functional materials with increasingly complex compositions is of current interest in science and technology. Complex rare-earth-based chalcogenides have specific thermal, electrical, magnetic and optical properties. Tetragadolinium bis[tetraoxidosilicate(IV)] oxide telluride, Gd4(SiO4)2OTe, was obtained accidentally while studying the Gd2Te3–Cu2Te system. The crystal structure was determined by means of single-crystal X-ray diffraction. The compound crystallizes in the space groupPnma. Three symmetry-independent gadolinium sites were determined. The excitation and emission spectra were collected at room temperature and at 10 K. Gd4(SiO4)2OTe appears to be a promising optical material when doped with rare-earth ions.


2012 ◽  
Vol 67 (1) ◽  
pp. 17-22
Author(s):  
Wen-Kui Dong ◽  
Guo-Hua Liu ◽  
Yin-Xia Sun ◽  
Xiu-Yan Dong ◽  
Xiong-Hou Gao

A dinuclear Cu(II) complex, [Cu2(L2)2] (H2L2 = 4-methoxysalicylaldehyde O-(2-hydroxyethyl)- oxime), has been synthesized through the complexation of Cu(II) acetate monohydrate with the ligand H2L1 (H2L1 = 5,5´ -dimethoxy-2,2´-[(ethylene)dioxybis(nitrilomethylidyne)]diphenol), and characterized by elemental analyses, IR, UV/Vis and emission spectra. The crystal structure of the Cu(II) complex has been determined by single-crystal X-ray diffraction. The catalysis by Cu(II) ions results in the unexpected cleavage of the N-O bonds in the ligand H2L1, giving a novel dialkoxo-bridged dinuclear Cu(II) complex possessing a Cu-O-Cu-O four-membered ring core instead of the expected salen-type bisoxime Cu-N2O2 complex


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