scholarly journals Electrochemiluminescence Study of Europium (III) Complex with Coumarin3-Carboxylic Acid

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Stefan Lis ◽  
Krzysztof Staninski ◽  
Tomasz Grzyb
Keyword(s):  
Aqueous Solution ◽  
Spectral Analysis ◽  
Energy Transfer ◽  
Solid State ◽  
Carboxylic Acid ◽  
Elemental Analysis ◽  
Aluminium Electrode ◽  
The Eu

The europium (III) complex of coumarin-3-carboxylic acid (C3CA) has been prepared and characterized on the basis of elemental analysis, IR, and emission (photoluminescence and electrochemiluminescence) spectroscopy. The synthesised complex having a formula Eu was photophysically characterized in solution and in the solid state. Electrochemiluminescence, ECL, of the system containing the Eu(III)/C3CA complex was studied using an oxide-covered aluminium electrode. The goal of these studies was to show the possibility of the use of electrochemical excitation of the Eu(III) ion in aqueous solution for emission generation. The generated ECL emission was very weak, and therefore its measurements and spectral analysis were carried out with the use of cut-off filters method. The studies proved a predominate role of the ligand-to-metal energy transfer (LMET) in the generated ECL.

scholarly journals Short Strong Hydrogen Bonds can Hinder Complex Formation: A Stability and Structure Study of Copper(II) Alkyl-N-iminodiacetic Acid Complexes in Aqueous Systems and Solid State

2021 ◽  
Author(s):  
Leif Häggman ◽  
Anders Cassel ◽  
Ingmar Persson
Keyword(s):  
Aqueous Solution ◽  
Coordination Chemistry ◽  
Solid State ◽  
Carboxylic Acid ◽  
Complex Formation ◽  
Hydrogen Bonds ◽  
Iminodiacetic Acid ◽  
Lewis Base ◽  
Polar Head ◽  
Ph Values

AbstractIn the present study the solution and coordination chemistry of copper(II)–alkyl-N-iminodiacetate systems are studied in aqueous solution by potentiometry, using ion selective copper and pH electrodes, EXAFS (extended X-ray absorption fine structure) and dye probe molecular absorption spectrophotometry. Alkyl-N-iminodiacetates with varying alkyl chain length, methyl (CH3–), n-hexyl (C6H13–), n-dodecyl (C12H25–) and n-octadecyl (C18H37–) were used to tune the amphiphilic properties of the ligands. The polar head groups have both oxygen (hard Lewis base) and nitrogen donor (border-line Lewis base) atoms. This means that metal ions with different bonding characteristics may bind these ligands differently. Furthermore, the chelating properties of the polar head group may be regulated by pH as the acid–base properties of the imine and carboxylic acid groups are different. Copper(II) forms two stable complexes with alkyl-N-iminodiacetates with short alkyl chains, present as monomers in aqueous solution, log10β1 = 11.10(2), log10β2 = 19.5(2) for methyl-N-iminodiacetate, and log10β1 = 12.22(4), log10β2 = 21.9(2) for n-hexyl-N-iminodiacetate. n-Octadecyl-N-iminodiacetic acid, present as large aggregates in acidic aqueous solution, has short strong hydrogen bonds between carboxylic acid and carboxylate groups in the surface of the aggregates, which hinder complex formation at pH values below 4, obstructs it in the pH region 4–7, while the complex formation behaves as for short-chained alkyl-N-iminodiacetates at pH > 7. The structure around copper in copper(II)–alkyl-N-iminodiacetate complexes in aqueous solution and solid state formed at different pH values and copper(II):alkyl-N-iminodiacetate ratios has been determined by EXAFS. The coordination chemistry of copper(II) shows four strong bonds in the equatorial plane, and two different Cu–O/N bond distances, ca. 0.2 Å apart, in the axial positions of a non-centrosymmetric tetragonally elongated octahedron.

Specific absorption in Y3Al5O12:Eu ceramics and the role of stable Eu2+ in energy transfer processes

2020 ◽  
Vol 8 (26) ◽  
pp. 8823-8839
Author(s):  
Maksym Buryi ◽  
Lubomír Havlák ◽  
Vítězslav Jarý ◽  
Jan Bárta ◽  
Valentyn Laguta ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Charge Transfer Transition ◽  
Vacuum Sintering ◽  
Absorption Bands ◽  
Specific Absorption ◽  
Transfer Processes ◽  
Ceramic Samples ◽  
The Eu

Several sets of Eu-doped Y3Al5O12 (YAG) ceramic samples were synthesized by the vacuum sintering technique. Absorption bands at 250, 370 and 550 nm in samples were attributed to the charge transfer transition in the EuY2+ + F+ pair center.

Synthesis, X-ray characterization and DFT studies of bis-N-imidazolylpyrimidine salts: the prominent role of hydrogen bonding and anion–π interactions

CrystEngComm ◽  
2014 ◽  
Vol 16 (38) ◽  
pp. 9043-9053 ◽  
Author(s):  
Francisca Orvay ◽  
Antonio Bauzá ◽  
Miquel Barceló-Oliver ◽  
Angel García-Raso ◽  
Joan J. Fiol ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Dft Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Π Interactions ◽  
New Compounds

Five new compounds have been synthesized and characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. They present interesting assemblies in the solid state dominated by H-bonding and anion–π interactions.

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto
Keyword(s):  
Cerebrospinal Fluid ◽  
Carboxylic Acid ◽  
Fibrinolytic Activity ◽  
Clinical Implications ◽  
Trans Form ◽  
Plate Method ◽  
Blood Samples ◽  
Fibrin Plate ◽  
The Brain

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

Europejski Komitet Ekonomiczno-Społeczny Unii Europejskiej – organ reprezentacji funkcjonalnej czy instytucja fasadowa?

2016 ◽  
pp. 66-81
Author(s):  
Leszek Graniszewski
Keyword(s):  
Civil Society ◽  
Social Conscience ◽  
The Eu

In the article the author draws his attention to the differences between the position of the Committee as a social conscience of the EU (that has been declared in the treaties and declarations) and the practical possibilities to fulfil this role and its results. The analysis featured covers the structure and the manner of operation of the Committee, and, in particular, the functions actually fulfilled by the Committee in its role of the bridge between the EU and the organised civil society.

The Service Sector in the Economy in Poland and European Union Countries

2015 ◽  
Vol 10 (3) ◽  
pp. 191-207
Author(s):  
Walentyna Kwiatkowska
Keyword(s):  
Service Sector ◽  
Value Added ◽  
Total Employment ◽  
Eu Countries ◽  
Gross Value Added ◽  
European Union Countries ◽  
Service Sectors ◽  
Sector Theory ◽  
The Eu

The role of the service sector in the economy is increasing in the process of socio-economic development. This tendency has been confirmed and explained by the three-sector theory formulated by A.G.B. Fisher, C. Clark, and J. Fourastie. The main goal of the paper is to show development tendencies in service sectors in Poland and the EU countries and assess them in view of the three-sector theory. The share of the service sector in the total employment and in the total gross value added in the years 2005-2013/2014 will be analysed together with two sub-sectors including market and non-market services. The research shows that the share of the service sector in total employment and total gross value added has been recently increasing in Poland as well as in other EU countries, but there is a gap in this process between Poland and the most developed EU countries. Moreover, in Poland, the role of market services has been recently increasing much faster than the role of non-market services. 

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