Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

1985 ◽  
Vol 50 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Jana Podlahová ◽  
Josef Šilha ◽  
Jaroslav Podlaha
Keyword(s):  
Metal Ion ◽  
Carboxyl Groups ◽  
Complex Solution ◽  
Square Planar ◽  
Weak Complexes ◽  
Carboxylic Groups ◽  
Uv Visible ◽  
The Stability ◽  
Tetrahedral Complexes ◽  
Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

scholarly journals Nano Synthesis and Characterization of Complex Derived from Silver Metal Conjugated with Midodrine Hydrochloride

2021 ◽  
Vol 37 (1) ◽  
pp. 157-161
Author(s):  
Namita Bharadwaj ◽  
Jaishri Kaushik
Keyword(s):  
Stability Constant ◽  
Silver Nanoparticle ◽  
Metal Ion ◽  
Ratio Method ◽  
Synthesis And Characterization ◽  
Face Centered Cubic ◽  
Uv Visible ◽  
Face Centered ◽  
The Stability

The stability constant Kf for the complexation of Ag(Ⅰ) metal ion with Midodrine hydrochloride were determinedby spectrophotometric method at room temperature .The colored complexes were measured at 300 nm. The stability constant of the complexes were found to be 5.47 by mole ratio method. The stoichiometry of the complexes formed between the Midodrine drug and Ag (Ⅰ) metal ion are 1:1 M/L ratio. Silver conjugated Midodrine hydrochloride Nano synthesized and characterized by UV/Visible spectroscopy, SEM, XRD and FT-IR. The UV/Visible spectra of Midodrine –Ag nanoparticle in the range of 322 nm. XRD conformThe crystallite size of Midodrine - Ag (Ⅰ) nanoparticles are found to be 64.5 nmfrom Debye Scherer formula.Thecrystallinity of nanoparticles is Face centered cubic structure. SEM conform of particle size and surface morphology, FTIR analyzed involvement of -NH2 group in Midodrine is the stabilized of silver nanoparticle. This research is focuses on complexation, Nano synthesis and characterization of Drug-silver nanoparticle for antihypotention therapy.

scholarly journals Azocalix[4]arene with three distal ethyl ester residues as a highly selective chromogenic sensor for Ca2+ ions

2018 ◽  
Vol 24 (3) ◽  
pp. 147-150
Author(s):  
Jie Wang ◽  
Hongyu Guan ◽  
Chunhua Ge ◽  
Ping Fan ◽  
Xijuan Xing ◽  
...  
Keyword(s):  
Stability Constant ◽  
Metal Ions ◽  
Ethyl Ester ◽  
Metal Ion ◽  
Visible Spectroscopy ◽  
Binding Properties ◽  
Metal Ion Complexation ◽  
Specific Selectivity ◽  
Uv Visible ◽  
The Stability

AbstractThree azocalix[4]arenes with distal ethyl ester residues, 5-phenylazo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (2), 5-(o-methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (3), 5-(p-Methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (4), were synthesized and their binding properties with metal ions were investigated by ultraviolet (UV)/visible spectroscopy. The chromogenic behavior of these compounds upon metal ion complexation indicates a specific selectivity toward Ca2+ ion in the presence of other cations tested. The stoichiometry of 3 to Ca2+ ion in the complex is 1:1 and the stability constant of the complex is 1.28×104m−1.

Metal Ion Complexes of Aromatic Amino Acids. II. N-Substituted Amino Benzoic Acids

1966 ◽  
Vol 21 (6) ◽  
pp. 527-529 ◽  
Author(s):  
J. Smith Decker ◽  
Herschel Frye
Keyword(s):  
Nitrogen Atom ◽  
Metal Ion ◽  
Amino Nitrogen ◽  
Aromatic Amino Acids ◽  
Coordination Complexes ◽  
Infrared Analysis ◽  
Visible Absorption ◽  
Aminobenzoic Acids ◽  
Square Planar ◽  
The Stability

This study has indicated that substitution on the nitrogen atom in aminobenzoic acid markedly decreases complex forming ability; this is especially true in the case of bulky electrophilic groups such as phenyl and acetyl. In these cases, the usual evidence accepted for the formation of coordination complexes was not present, and it was therefore concluded that only salts were formed from ligands bearing these groups on the nitrogen atom. The presence of the methyl group on the amino nitrogen reduces the ability to form complexes and also reduces the stability of the few complexes formed; this is in contrast to the substitution of methyl and other small groups on the ring.Using carbon-hydrogen ratios and infrared data, the structures assigned to the complexes are square planar with the exception of tetrahedral zinc (II) complexes. Usually water was present in the complex which stubbornly resisted removal; at least some of this water may have been coordinated, particularly in the cases where cations are known to prefer octahedral symmetry. The ratios for the complexes prepared from N-methylanthranilic acid were in every case two ligand anions to one metal cation. Ultraviolet-visible data were obtained with difficulty and in general substantiated the evidence obtained by infrared analysis. The presence of water tended to obscure these results, and the very limited solubility of the complexes in water and in other appropriate solvents precluded intensive analysis via ultraviolet-visible absorption spectrophotometry.Five coordination complexes and twenty-eight salts were produced of the forty-four combinations possible with these four acids as ligand source. The five complexes studied were previously unreported; however, the copper (II) and cadmium (II) complexes of N-methyl- and of N-phenylarthranilic acid reported by other workers 2 were, on the basis of the criteria used in this study, salts rather than coordination complexes.The stability series as determined from the degree of shifting in the infrared regions around 3400 cm-1 and 1000 cm-1 were shown to differ markedly from those series obtained for ring substituted aminobenzoic acids.

scholarly journals New Brightener for Zn-Fe Alloy Plating from Sulphate Bath

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
B. M. Praveen ◽  
T. V. Venkatesha
Keyword(s):  
Grain Size ◽  
Metal Ion ◽  
Condensation Product ◽  
Spectroscopic Studies ◽  
Sem Images ◽  
Alloy Electrodeposition ◽  
Fine Grained ◽  
Polarization Studies ◽  
Uv Visible ◽  
Sulphate Bath

Zn-Fe alloy electrodeposition was carried out in the presence of condensation product 2-{[(1E)-(3,4-dimethoxyphenyl)methylidene]amino}-3-hydroxypropanoic acid formed between veratraldehyde and serine in acid sulphate bath. Hull cell was used for optimizing the operating parameters and bath constituents. During deposition, the potential was shifted towards cathodic direction in the presence of addition agents and brightener. The polarization studies show that deposition taking place in basic bath and optimum bath was 1.08 and 1.15 V, respectively. Current efficiency and throwing power were reached around 85% and 26%, respectively. The SEM images of bright deposit indicated its fine-grained nature and appreciable reduction in the grain size. XRD studies have showed that the grain size of the deposit generated from optimum bath was 16 nm. UV-visible spectroscopic studies confirm the formation of complex between metal ion and brightener.

Synthesis and properties of a sterically encumbered poly(thienylene vinylene): poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene]

1998 ◽  
Vol 76 (11) ◽  
pp. 1524-1529
Author(s):  
Jimmy Lowe ◽  
Carl Bartels ◽  
Steven Holdcroft
Keyword(s):  
Ftir Spectroscopy ◽  
Electrically Conducting ◽  
H Nmr ◽  
Visible Photoluminescence ◽  
Micron Size ◽  
Visible Irradiation ◽  
Uv Visible ◽  
The Stability ◽  
Doped Polymer ◽  
Polythiophene Derivative

Electrically conducting poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene] was synthesized and structurally characterized by UV-visible, 1H NMR, and FTIR spectroscopy. The head-to-head arrangement of the alkylthiophene dyads directly affects the UV-visible, photoluminescence, and electroluminescence maxima of the polymer. The conductivity of the doped polymer was measured to be ~2 S cm-1 and the stability of the oxidized polymer possessing various dopants was compared. UV-visible irradiation of PDHDTE rendered the films insoluble and photolithography was used to produce micron-size images. FTIR was used to monitor the photoproducts during photolysis of PDHDTE. Mechanisms of photooxidation were proposed, based on the photoproducts observed.Key words: polythiophene derivative, head-to-head dyad, photolithography, photooxidation, electroluminescence.

scholarly journals Crystal structures of [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O containing MnO6+1capped trigonal prisms and [Cu(Hspar)2](bdc)·2H2O containing CuO4squares (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate)

2016 ◽  
Vol 72 (1) ◽  
pp. 96-101
Author(s):  
Zhe An ◽  
Jing Gao ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Crystal Structures ◽  
Metal Ion ◽  
Three Dimensional ◽  
Trigonal Prism ◽  
Planar Geometry ◽  
Cationic Complex ◽  
Counter Ion ◽  
Square Planar

The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′)bis(sparfloxacin-κ2O,O′)manganese(II) dihydrate, [Mn(C8H4O4)(C19H22F2N4O3)2(H2O)0.25]·2H2O or [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O, (I), and bis(sparfloxacin-κ2O,O′)copper(II) benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O3)2](C8H4O4)·2H2O or [Cu(Hspar)2](bdc)·2H2O, (II), are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate). The Mn2+ion in (I) is coordinated by twoO,O′-bidentate Hspar neutral molecules (which exist as zwitterions) and anO,O′-bidentate bdc dianion to generate a distorted MnO6trigonal prism. A very long bond [2.580 (12) Å] from the Mn2+ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II), the Cu2+ion lies on a crystallographic inversion centre and a CuO4square-planar geometry arises from its coordination by twoO,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I) and (II) feature intramolecular N—H...O hydrogen bonds, which closeS(6) rings. In the crystals of both (I) and (II), the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

Extended X-ray absorption fine structure and multiple-scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n(n= −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1-hexene)

2015 ◽  
Vol 22 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Weiwei Gu ◽  
Hongxin Wang ◽  
Kun Wang
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible ◽  
Edge Features ◽  
X Ray Absorption

A series of Ni dithiolene complexes Ni[S2C2(CF3)]2n(n= −2, −1, 0) (1,2,3) and a 1-hexene adduct Ni[S2C2(CF3)2]2(C6H12) (4) have been examined by NiK-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopies. Ni XANES for1–3reveals clear pre-edge features and approximately +0.7 eV shift in the NiK-edge position for `one-electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for1,2and3(2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ∼0.022 Å for each `one-electron' oxidation. The changes in NiK-edge energy positions and Ni—S distances are consistent with the `non-innocent' character of the dithiolene ligand. The Ni—C interactions at ∼3.0 Å are analyzed and the multiple-scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1-hexene adduct4presents no pre-edge feature, and its NiK-edge position shifts by −0.8 eV in comparison with its starting dithiolene complex3. Consistently, EXAFS also showed that the Ni—S distances in4elongate by ∼0.046 Å in comparison with3. The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π-electron density to the LUMO of3as suggested by UV/visible spectroscopy in the literature.

Novel Inorganic Hydrogels Based on The Polymerization of Cyanometalate Transition Metal Complexes With [PdCl4]2-: A New Approach To Ceramic And Alloy Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
Andrew B. Bocarsly ◽  
Gireesh Kumar ◽  
Marija Heibel
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Sol Gel ◽  
Metallic Matrix ◽  
Linear Polymers ◽  
New Approach ◽  
Square Planar ◽  
Delafossite Structure ◽  
Cyanide Ligand ◽  
Sol Gel Transition

ABSTRACTThe reaction of a wide variety of cyanometalate complexes of the general form [M(CN)x]n- (where M= a transition metal ion) with square planar [PdCl4]2- in aqueous solution leads to the formation of linear polymers. Polymerization occurs via substitution of chloride ligands on the Pd(II) centers, by the nitrogen end of the cyanide ligand to generate extended bridging cyanide structures. Upon generation at room temperature polymer solutions of this type under go a sol-gel transition to generate robust hydrogels having water content in excess of 95%. In the case of the cyanocobaltate/tetrachloropalladate gel, pyrolysis at 900°C produces ferromagnetic Pd/Co metallic alloys having novel morphological character. Materials formed with a hydrogel having a 2:1 Pd to Co stoichiometry are found to be “sponge-like”. When placed in water, the metallic matrix swells becoming pliable and holding up to seven equivalents of water per metal site. The conductivity and magnetic properties of this material are maintained in the swollen state. Sintering of the Pd/Co hydrogel in air generates the layered oxide, PbCoO2 having a delafossite structure.

scholarly journals Experimental Investigation on Stability, Viscosity, and Electrical Conductivity of Water-Based Hybrid Nanofluid of MWCNT-Fe2O3

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 136
Author(s):  
Solomon O. Giwa ◽  
Mohsen Sharifpur ◽  
Mohammad H. Ahmadi ◽  
S. M. Sohel Murshed ◽  
Josua P. Meyer
Keyword(s):  
Electrical Conductivity ◽  
Visual Inspection ◽  
Volume Concentration ◽  
Working Fluid ◽  
Hybrid Nanofluid ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Hybrid Nanofluids ◽  
Uv Visible ◽  
The Stability

The superiority of nanofluid over conventional working fluid has been well researched and proven. Newest on the horizon is the hybrid nanofluid currently being examined due to its improved thermal properties. This paper examined the viscosity and electrical conductivity of deionized water (DIW)-based multiwalled carbon nanotube (MWCNT)-Fe2O3 (20:80) nanofluids at temperatures and volume concentrations ranging from 15 °C to 55 °C and 0.1–1.5%, respectively. The morphology of the suspended hybrid nanofluids was characterized using a transmission electron microscope, and the stability was monitored using visual inspection, UV–visible, and viscosity-checking techniques. With the aid of a viscometer and electrical conductivity meter, the viscosity and electrical conductivity of the hybrid nanofluids were determined, respectively. The MWCNT-Fe2O3/DIW nanofluids were found to be stable and well suspended. Both the electrical conductivity and viscosity of the hybrid nanofluids were augmented with respect to increasing volume concentration. In contrast, the temperature rise was noticed to diminish the viscosity of the nanofluids, but it enhanced electrical conductivity. Maximum increments of 35.7% and 1676.4% were obtained for the viscosity and electrical conductivity of the hybrid nanofluids, respectively, when compared with the base fluid. The obtained results were observed to agree with previous studies in the literature. After fitting the obtained experimental data, high accuracy was achieved with the formulated correlations for estimating the electrical conductivity and viscosity. The examined hybrid nanofluid was noticed to possess a lesser viscosity in comparison with the mono-particle nanofluid of Fe2O3/water, which was good for engineering applications as the pumping power would be reduced.

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