Synthesis and Optical Properties of some Novel Bis-1,3,4-Oxadiazoles

2015 ◽  
Vol 1104 ◽  
pp. 131-135
Author(s):  
Hua Liu ◽  
Lin Lu ◽  
Dun Jia Wang
Keyword(s):  
Optical Properties ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Chloroform Solution ◽  
Emission Spectra ◽  
Pyridine Derivatives ◽  
Fluorescence Emission Spectra ◽  
H Nmr ◽  
Uv Illumination ◽  
Oxadiazole Derivatives

Three 2,6-bis (1,3,4-oxadiazol-2-yl) pyridine derivatives were synthesized and their structures were conformed by1H NMR, FTIR, MS techniques and elemental analysis. The UV–Vis absorption and fluorescence emission spectra of these compounds were investigated in chloroform solution. The results showed that these bis-1,3,4-oxadiazole derivatives had broad and strong absorption at 278−302 nm in the UV–Vis spectra and exhibited fluorescence emission at 338 −367 nm under UV illumination in fluorescence spectra. It was found that the nature of the substituents at benzene ring in bis-1,3,4-oxadiazole derivatives had a significant impact on their photoluminescence behaviors.

scholarly journals Luminescent Hybrid Materials Based on Curcumin Derivatives Embedded in Palygorskite

2018 ◽  
Vol 55 (1) ◽  
pp. 63-67
Author(s):  
Monica Florentina Raduly ◽  
Valentin Raditoiu ◽  
Alina Raditoiu ◽  
Luminita Eugenia Wagner ◽  
Viorica Amariutei ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Hydroxyl Groups ◽  
Fluorescent Properties ◽  
Fluorescence Emission Spectra ◽  
Curcumin Derivatives ◽  
Absorption Studies ◽  
Inorganic Matrix

The seven curcumin derivatives were deposited on palygorskite in order to obtain hybrid materials. The fluorescence emission spectra of the obtained materials show a decrease in fluorescence intensity relative to the respective dyes, due to the environments around the dyestuff molecules created in the host matrices. Absorption studies show the best adsorption on the inorganic matrix, for the compounds with the hydroxyl groups. Correlating fluorescence spectra of hybrid materials with the results for absorption spectra of the dyes adsorbtion on the surface of the clay lead to the conclusion that a high percentage of the adsorbed dye had the effect of fluorescence quenching. Thus, it was confirmed that the fluorescent properties of hybrid materials depend on the interactions established between the fluorescent dyestuff and the inorganic network.

Study on a New Coumarin Derivative as Fluorescent Probe for Hg2+ Ions

2014 ◽  
Vol 904 ◽  
pp. 99-102
Author(s):  
Hong Qi Li ◽  
Zhen Chen ◽  
Hao Chen ◽  
Jia Wei Zhang ◽  
Yan Tai Chen ◽  
...  
Keyword(s):  
Metal Ions ◽  
Fluorescent Probe ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Coumarin Derivative ◽  
Emission Peak ◽  
Fluorescence Emission Spectra ◽  
Maximum Emission ◽  
H Nmr ◽  
C Nmr

A new coumarin derivative L was synthesized and characterized by1H NMR,13C NMR, IR and mass spectrum. UV-Vis and fluorescence emission spectra of L without or with different anions (NO2, F, Cl, HSO3, HSO4, AcO or NO3) or metal ions were measured, which showed while addition of anions or metal ions Mg2+, Zn2+, Ca2+, Cu2+, Ni2+, Co2+, Fe3+or Al3+led to decrease in intensity of the maximum emission peak at about 480 nm, addition of Hg2+ions caused increase in intensity of the maximum emission peak, suggesting that L may act as a fluorescent probe for detection of Hg2+ions.

A New Schiff’s Base Fluorescent Sensor for the Selective Detection of Mercury Ion

2011 ◽  
Vol 239-242 ◽  
pp. 1105-1108 ◽  
Author(s):  
Xue Mei Wang ◽  
Hua Yan ◽  
Yong Chen ◽  
He Bin Bao
Keyword(s):  
Fluorescent Sensor ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Mercury Ion ◽  
Fluorescence Measurement ◽  
Fluorescence Emission Spectra ◽  
H Nmr ◽  
Complex Process ◽  
Characteristic Wavelength ◽  
Ft Ir

A new Hg2+-sensing and selective fluorescent sensor, 1-(1-pyrenecarboxaldehyd e)-thiocarbohydrazone, was synthesized and characterized by elemental analysis, FT-IR and 1H NMR spectra. Its fluorescence and recognition properties to the mercury ion were studied by the fluorescence emission spectra. With adding mercury ion into solution, the fluorescence emission intensities at different characteristic wavelength changed continually. Hence the ratiometric fluorescence measurement was used for detecting the complex process. It was found that a 1:1 stoichiometry complex is formed between the mercury ion and the compound with the association constants were 2.04×105 L/mol, respectively. And the detection limits of the mercury ion were 2.52×10-8 mol/L.

scholarly journals Solid state fluorescence of proteins in high throughput mode and its applications

F1000Research ◽  
2019 ◽  
Vol 2 ◽  
pp. 82
Author(s):  
Saurabh Gautam ◽  
Munishwar N Gupta
Keyword(s):  
Solid State ◽  
High Throughput ◽  
Fluorescence Spectra ◽  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Simple Method

Direct comparison between fluorescence spectra of a sample in solution and solid state form is valuable to monitor the changes in protein structure when it is “dried” or immobilized on a solid surface (for biocatalysis or sensor applications). We describe here a simple method for recording fluorescence emission spectra of protein powders without using any dedicated accessory for solid samples in a high-throughput format. The 96-well plate used in our studies, was coated black from all the sides and the excitation and emission paths are identical and are from the top of the well. These two features minimize scatter and provide fairly noise free spectra. Even then the fluorescence intensity may be dependent upon many factors such as the extent of protein aggregation, morphology and sizes of the protein particles. Hence, (changes in) λmax emission may be a more reliable metric in the case of fluorescence spectra of proteins in the solid state. However, any large changes in the intensity could indicate changes in the microenvironment of the fluorophore. The fluorescence emission spectra were blue-shifted (4 to 9 nm), showed an increase in the intensity for different proteins studied upon lyophilization, and were similar to what has been reported by others using available commercial accessories for solid state samples. After validating that our method worked just as well as the dedicated accessories, we applied the method to compare the fluorescence emission spectra of α-chymotrypsin in solution, precipitated form, and the lyophilized powder form. We further examined the fluorescence emission spectra of green fluorescent protein (GFP) in solution and solid form. We also analyzed fluorescence resonance energy transfer (FRET) between tryptophan (Trp57) and the cyclic chromophore of GFP. These findings pointed towards the change in the microenvironment around the cyclic chromophore in GFP upon lyophilization.

scholarly journals Solid state fluorescence of proteins in high throughput mode and its applications

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 82
Author(s):  
Saurabh Gautam ◽  
Munishwar N Gupta
Keyword(s):  
Solid State ◽  
High Throughput ◽  
Fluorescence Spectra ◽  
Tertiary Structure ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Red Shift ◽  
Solid Samples ◽  
Fluorescence Emission Spectra ◽  
Simple Method

A simple method to determine fluorescence emission spectra of proteins in solid state is described. The available commercial accessories can only accommodate solid samples and hence do not allow a direct comparison between fluorescence spectra of a sample in solution and solid state form. Such comparisons are valuable to monitor the changes in protein structure when it is “dried” or immobilized on a solid surface (for biocatalysis or sensor applications). The commercially available accessories also do not allow working in a high throughput mode. We describe here a simple method for recording fluorescence emission spectra of protein powders without using any dedicated accessory for solid samples. This method works with a 96-well plate format. It enables the comparison of fluorescence spectra of a sample in a solid state with solution spectra, using comparable quantities of protein. The fluorescence emission spectra were blue-shifted (4 to 9 nm), showed an increase in the intensity for different proteins studied upon lyophilization, and were similar to what has been reported by others using available commercial accessories for solid state samples. After validating that our method worked just as well as the dedicated accessories, we applied the method to compare the fluorescence emission spectra of α-chymotrypsin in solution, precipitated form and the lyophilized powder form. α-Chymotrypsin in solution showed a λmax of 335 nm while a high-activity preparation of the same enzyme for non-aqueous media, known as enzyme precipitated and rinsed with propanol (EPRP), showed an increase in the intensity of the fluorescence emission spectra. However, there was a small red shift of 2 nm (λmax of 337 nm) in contrast to lyophilized powder which showed a λmax of 328 nm. This is due to a difference in the tertiary structure of the protein as well as the microenvironment of aromatic residues between the two preparations. We further examined the fluorescence emission spectra of green fluorescent protein (GFP) in solution and solid form. The relative fluorescence intensity of lyophilized GFP powder was decreased significantly to 17% as compared to GFP in solution, and showed a red shift of 4 nm in the emission λmax. It was found that fluorescence resonance energy transfer (FRET) between tryptophan (Trp57) and the cyclic chromophore of GFP was significantly diminished. This indicated the change in the microenvironment around the cyclic chromophore in GFP upon lyophilization.

scholarly journals Study of the behavior of short chains in print paper subjected to a natural aging

2018 ◽  
Vol 31 (4) ◽  
pp. 58-62
Author(s):  
José Martínez Mendoza ◽  
Alejandra Nieto-Villena ◽  
José Angel De la Cruz-Mendoza ◽  
Gerardo Ortega-Zarzosa ◽  
Azdrubal Guerrero-Serrano
Keyword(s):  
Structural Stability ◽  
Ethyl Alcohol ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Natural Aging ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Paper Making ◽  
Intensity Changes

Degradation of paper through time can be measured by monitoring the intensity changes in the band located at 620 nm of its emission fluorescence spectra. The behavior of this band is closely related to the structural stability of the short cellulose chains. A fast degradation of these cellulose chains, mainly lignin, translates in the rapid denaturation of paper occurring at its first aging state. This work proposes a method to reincorporate short cellulose chains in the structure of aged paper through its immersion during 24 h in a solution based on ethyl alcohol and extracts of wood pieces. Results of fluorescence spectra measurements indicate that the short cellulose chains in the solution get embedded in the old paper, making the shape and intensity of the fluorescence emission spectra peaks of new and old paper almost indistinguishable. This behavior provides a desirable approach to analyze, preserve and restore aged paper documents.

scholarly journals A new fluorescent chemosensor for fluoride anion based on a pyrrole–isoxazole derivative

2011 ◽  
Vol 7 ◽  
pp. 46-52 ◽  
Author(s):  
Zhipei Yang ◽  
Kai Zhang ◽  
Fangbin Gong ◽  
Shayu Li ◽  
Jun Chen ◽  
...  
Keyword(s):  
Density Functional ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluoride Anion ◽  
Fluorescence Emission Spectra ◽  
Functional Theory ◽  
Binding Motifs ◽  
H Nmr ◽  
Isoxazole Derivative ◽  
Fluoride Detection

Molecules containing polarized NH fragments that behave as anion-binding motifs are widely used as receptors for recognition and sensing purposes in aprotic solvents. We present here a new example of a receptor, 3-amino-5-(4,5,6,7-tetrahydro-1H-indol-2-yl)isoxazole-4-carboxamide (receptor 1), which contains pyrrole, amide and amino subunits. This receptor shows both changes in its UV–vis absorption and fluorescence emission spectra upon the addition of F−, resulting in highly selectivity for fluoride detection over other anions, such as Cl−, Br−, I−, HSO4 −, H2PO4 − and AcO− in CH3CN. 1H NMR titration, time-dependent density functional theory (TDDFT) calculations and other experiments confirm that the sensing process is brought about by deprotonation of the pyrrole-NH in receptor 1.

Lewis acid induced spectral changes of sterically hindered and unhindered meso-tetra(aryl)porphyrins: fluorescence emission spectra

2020 ◽  
Vol 44 (7) ◽  
pp. 3028-3037
Author(s):  
Aida G. Mojarrad ◽  
Saeed Zakavi
Keyword(s):  
Absorption Spectra ◽  
Lewis Acid ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Molecular Complexes ◽  
Fluorescence Emission Spectra ◽  
Spectral Changes ◽  
Sterically Hindered

Fluorescence spectra of a series of electron-rich and electron-deficient meso-tetra(aryl)porphyrins and their molecular complexes with DDQ, TCNE and BF3 were investigated and compared. In spite of the great resemblance between the absorption spectra of the molecular complexes, large differences were observed between their emission spectra.

A Fluorescence Ratiometric Probe for Imaging of Acidic pH in Living Cells

2013 ◽  
Vol 864-867 ◽  
pp. 83-87
Author(s):  
Ling Liang Long ◽  
Yan Jun Wu ◽  
Lin Wang
Keyword(s):  
Fluorescence Emission ◽  
Emission Spectra ◽  
Living Cells ◽  
Acidic Ph ◽  
X Ray Diffraction ◽  
Fluorescence Emission Spectra ◽  
H Nmr ◽  
Ph Imaging ◽  
Visible Effect ◽  
Ratiometric Probe

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.

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