Imidazolato-bridged complexes of copper(II)

1970 ◽  
Vol 23 (10) ◽  
pp. 1973 ◽  
Author(s):  
ME Bridson ◽  
WR Walker
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Aqueous Solutions ◽  
Electronic Spectra ◽  
Empirical Formula ◽  
Spectroscopic Data ◽  
Bridging Ligand

Compounds of the empirical formula Cu(HIm)2(Im)X [where X = NO3-, ClO4-, Cl-, Br-, and I-; HIm = imidazole and Im- = anion of imidazole] have been prepared and investigated. Evidence for the imidazolato anion acting as a bridging ligand in the solid state is based on magnetic and spectroscopic data. The electronic spectra of aqueous solutions of tetrakisimidazolecopper(11) compounds suggest the presence of the binuclear hydroxy-bridged cation (1) : (See diagram in article) which is also furnished by the imidazolato-bridged species in aqueous solution.

Copper(II) and Nickel(II) Complexes of Pentaaza Macrocyclic Ligands

1987 ◽  
Vol 40 (2) ◽  
pp. 347 ◽  
Author(s):  
P Osvath ◽  
NF Curtis ◽  
DC Weatherburn
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Electronic Spectra ◽  
Macrocyclic Ligands ◽  
Distorted Octahedral Environment ◽  
Trigonal Bipyramidal ◽  
Octahedral Environment ◽  
Distorted Octahedral

The preparations of the pentaazamacrocyclic ligands 1,4,7,10,13-pentaazacyclopentadecane, cpad , l,4,7,l0,13-pentaazacyclohexadecane, ched , l,4,7,l0,14-pentaazacycloheptadecane, chad , 1,4,7,11,14-pentaazacycloheptadecane, cnad , 1,4,7,11,15-pentaazacyclooctadecane, cnad , 1,4,8,11,15-pentaazacyclooctadecane, cnad , 1,4,8,12,16-pentaazacyclononadecane, cnad , and 1,5,9,13,17-pentaazacycloeicosane, ceic , as well as the new linear pentaamine N-(3-aminopropy1)- N'-[3-[(3-aminopropyl)amino] propyl ]propane-1,3-diamine, tpah , are described. Copper(II) and nickel(II) complexes of the above ligands have been prepared and characterized. The nickel(II) complexes of the smaller macrocycles and the linear pentaamine contain NiII in a tetragonally distorted octahedral environment in the presence of coordinating anions or in aqueous solution but the [Ni( cnad )]2+ and [Ni( ceic )]2+ cations are five-coordinate both in the solid state and in aqueous solution. The copper(II) complexes of the macrocyclic pentaamines appear to be square-pyramidal on the basis of their electronic spectra, whereas the complex [cu( tpah )]2+ is probably trigonal- bipyramidal.

Chemical speciation of polynuclear complexes containing [Ln2M3L6] units

2008 ◽  
Vol 80 (6) ◽  
pp. 1303-1316 ◽  
Author(s):  
Julia Torres ◽  
Carlos Kremer ◽  
Sixto Domínguez
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Metal Ion ◽  
Solution Chemistry ◽  
Structural Flexibility ◽  
Polynuclear Complexes ◽  
Bridging Ligand ◽  
Copper Compounds ◽  
Mononuclear Complexes ◽  
Polynuclear Species

Polynuclear complexes are widely regarded as potential materials in separation, catalysis, gas storage, and molecular recognition. Those complexes including lanthanide (Ln) ions in the heterobimetallic assembly enhance the structural flexibility and increase the thermodynamic stability. Up to now, the studies on these heteropolynuclear complexes have been mostly focused on lanthanide-copper compounds in the solid state. We have expanded the studies to solution chemistry, to know if such polynuclear species can also exist in aqueous solution. In this work, potentiometric titrations (25.0 °C, and I = 0.50 M Me4NCl) were carried out for systems containing a Ln ion (La, Ce, Sm), a bridging ligand (oda or ida), and a second metal ion. We found that polynuclear units can be formed with MII (Mn, Fe, Co, Ni, Cu, Zn, Cd, and VO2+) and MIII (Fe, Al) ions, and can be predominant in aqueous solution. Species like [Ln2M3L6] or [Ln2M3L6(OH)n]n- (n = 3, 6) can exist in solution, representing the same 2:3:6 stoichiometry found in the solid state. The presence of an amino group in the ida ligand makes the mononuclear complexes with 3d metal ions more stable, preventing to some extent the formation of polynuclear complexes.

Photoproducts of 7-Hydroxycoumarins in Aqueous Solution

2012 ◽  
Vol 65 (10) ◽  
pp. 1451 ◽  
Author(s):  
Gerald J. Smith ◽  
Roderick J. Weston ◽  
Ying Tang ◽  
Yinrong Lu ◽  
Jolon M. Dyer
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Excited State ◽  
Mass Spectrum ◽  
Solid State ◽  
Aqueous Solutions ◽  
Fluorescence Spectra ◽  
Major Product ◽  
Structural Assignment ◽  
Esi Mass Spectrometry

Near-UV irradiation of aqueous solutions of 7-hydroxy-6-methoxycoumarin (scopoletin) and 6,7-dihydroxycoumarin (esculetin) resulted in the formation of dimers. Substantially greater amounts of the 7-hydroxy-6-methoxycoumarin photodimer were produced compared with that of 6,7-dihydroxycoumarin. Fluorescence spectra indicated that the initial photolytic reaction involves the excited state of the phenolate form of the monomeric coumarin. The electro-spray ionization (ESI) mass spectrum suggested that the major product (with a sodiated quasimolecular ion at m/z 405) from the photolysis of scopoletin in water had formed by oxidative dimerisation and possibly had a 3,3′-bond. A second dimer (with a sodiated quasimolecular ion at m/z 407) was probably a 2 + 2 cyclodimer. This work concluded that photolysis of coumarins in water results in oxidative dimerisation whereas photolysis in the solid state or in organic solvents results in cyclodimerisation. Minor monomeric photoproducts were a dihydroxy-6-methoxycoumarin from 7-hydroxy-6-methoxycoumarin and a trihydroxycoumarin from 6,7-dihydroxycoumarin. During ESI-mass spectrometry (ESI-MS), sodiated quasimolecular ions of the photodimer formed more readily than protonated quasimolecular ions and the sodiated ions did not fragment readily. Protonated quasimolecular ions of the monomeric coumarins formed more readily than their sodiated counterparts and the protonated ions fragmented to create daughter ion spectra that were useful for chemical structural assignment.

Effect of thermal history of aqueous solutions of KCl on the metastable zone width

1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Thermal History ◽  
Equilibrium Solubility ◽  
Metastable Zone Width ◽  
Zone Width ◽  
Preceding Experiment ◽  
History Of ◽  
Metastable Zone ◽  
The Given

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.

scholarly journals I. Thermo-electric behaviour of aqueous solutions with mercurial electrodes

1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Internal Diameter ◽  
Thermo Electric ◽  
Thin Glass ◽  
Mercury Surface

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.

scholarly journals Meta-studtite stability in aqueous solutions. Impact of HCO3−, H2O2 and ionizing radiation on dissolution and speciation

2021 ◽  
Author(s):  
Junyi Li ◽  
Zoltán Szabó ◽  
Mats Jonsson
Keyword(s):  
Aqueous Solution ◽  
Ionizing Radiation ◽  
Aqueous Solutions ◽  
Carbonate Complexes ◽  
C Nmr

Four different uranyl-(peroxide)-carbonate complexes were identified during studtite and meta-studtite dissolution in aqueous solution containing 10 mM HCO3− by 13C NMR.

scholarly journals Visualization of microwave near-field distribution in sodium chloride and glucose aqueous solutions by a thermo-elastic optical indicator microscope

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhirayr Baghdasaryan ◽  
Arsen Babajanyan ◽  
Levon Odabashyan ◽  
Jung-Ha Lee ◽  
Barry Friedman ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Field Distribution ◽  
Near Field ◽  
Absorption Properties ◽  
Novel Approach ◽  
Concentration Changes ◽  
Biological Liquids ◽  
Optical Indicator ◽  
Distribution Intensity

AbstractIn this study, a new optical method is presented to determine the concentrations of NaCl and glucose aqueous solutions by using a thermo-elastic optical indicator microscope. By measuring the microwave near-field distribution intensity, concentration changes of NaCl and glucose aqueous solutions were detected in the 0–100 mg/ml range, when exposed to microwave irradiation at 12 GHz frequency. Microwave near-field distribution intensity decreased as the NaCl or glucose concentration increased due to the changes of the absorption properties of aqueous solution. This method provides a novel approach for monitoring NaCl and glucose in biological liquids by using a CCD sensor capable of visualizing NaCl and glucose concentrations without scanning.

Separation of phenylenediamine isomers by using decamethylcucurbit[5]uril

2021 ◽  
Author(s):  
Long Cao ◽  
Han-Ling Guo ◽  
Rui Lian Lin ◽  
Li-Fei Tian ◽  
Zhi-Hua Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Solid State ◽  
Phenylenediamine Isomers

Using multiple techniques, this work studied the binding behaviors of decamethylcucurbit[5]uril (Me10Q[5]) with o-, m- and p-phenylenediamine (PDA) isomers both in solid state and in aqueous solution. Experimental data indicate...

Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Selective Removal ◽  
Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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