Synthesis and Characterization of A New Weak Ferromagnet: Fe(II) Ethylene-BIS-(Phosphonates)

1998 ◽  
Vol 547 ◽  
Author(s):  
C. Bellitto ◽  
F. Federici ◽  
M.R. Mahmoud ◽  
S.A. Ibrahim
Keyword(s):  
Metal Ion ◽  
Three Dimensional ◽  
Electronic Configuration ◽  
Antiferromagnetic Order ◽  
Zero Field ◽  
Thermal Variation ◽  
Weak Ferromagnet ◽  
Uv Visible ◽  
Spin Electronic

AbstractIron(II)-ethylene-bis-(phosphonates), Fe2[O3P-(CH2)2-PO3]·2H2O was synthesized by reaction of [FeSO4]·7H2O and the corresponding ethylene-bis-(phosphonic acid) and it was characterized by X-ray powder diffraction, thermogravimetry, UV-visible and infrared spectroscopy, and the magnetic properties were studied by a SQUID magnetometer. The metal-ion is in the d6 high-spin electronic configuration and it appears to have an octahedral coordination. The thermal variation of the d.c. magnetic susceptibility of Fe2[O3P-(CH2)2-PO3]·2H2O follows the Curie-Weiss law, with a negative Weiss constant of θ =-55K. Below 100K, the susceptibility increases until a peak at TN=24K is observed, and this is associated to the three-dimensional antiferromagnetic order. Below 24K, Fe2[O3P-(CH2)2-PO3]·2H2O behaves as a “weak” ferromagnet and it represents an example of an unusual kind of molecular-based magnetic materials, having a finite zero-field magnetization.

Synthesis and characterization of novel phthalocyanines with nitrone substituents

2007 ◽  
Vol 11 (01) ◽  
pp. 42-49 ◽  
Author(s):  
B. Narayana Achar ◽  
T. M. Mohan Kumar
Keyword(s):  
Electrical Conductivity ◽  
Metal Ion ◽  
Activation Parameters ◽  
Central Metal ◽  
Metal Phthalocyanines ◽  
Lattice Constants ◽  
X Ray Crystallography ◽  
Uv Visible ◽  
First Time

A novel series of nitrone-substituted, metal phthalocyanine complexes (the central metal ion being Co , Ni and Cu , respectively) were synthesized for the first time in pure state with quantitative yield. These complexes were characterized using elemental analysis, UV-visible, IR-spectroscopy, magnetic susceptibility, X-ray crystallography, and thermogravimetry. All three complexes had a monoclinic structure with different crystal lattice constants. Horowitz-Metzger, Coats-Redfern and Broido's relations were employed to calculate the kinetic and activation parameters associated with the thermal decomposition of the above complexes. Electrical conductivity studies were undertaken for all three complexes using a two-probe technique in the temperature range 30-200°C. They showed an improvement of 103-105 times the electrical conductivity at room temperature, compared to the corresponding unsubstituted metal phthalocyanines.

scholarly journals Co(II) Coordination in Prokaryotic Zinc Finger Domains as Revealed by UV-Vis Spectroscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Valeria Sivo ◽  
Gianluca D’Abrosca ◽  
Luigi Russo ◽  
Rosa Iacovino ◽  
Paolo Vincenzo Pedone ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Coordination Sphere ◽  
Metal Ion ◽  
Electronic Configuration ◽  
Transition Band ◽  
Tetrahedral Geometry ◽  
Vis Spectroscopy ◽  
Zinc Finger Domains ◽  
Spectroscopic Probe

Co(II) electronic configuration allows its use as a spectroscopic probe in UV-Vis experiments to characterize the metal coordination sphere that is an essential component of the functional structure of zinc-binding proteins and to evaluate the metal ion affinities of these proteins. Here, exploiting the capability of the prokaryotic zinc finger to use different combinations of residues to properly coordinate the structural metal ion, we provide the UV-Vis characterization of Co(II) addition to Ros87 and its mutant Ros87_C27D which bears an unusual CysAspHis2 coordination sphere. Zinc finger sites containing only one cysteine have been infrequently characterized. We show for the CysAspHis2 coordination an intense d-d transition band, blue-shifted with respect to the Cys2His2 sphere. These data complemented by NMR and CD data demonstrate that the tetrahedral geometry of the metal site is retained also in the case of a single-cysteine coordination sphere.

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 Synthesis and Characterization of Lanthanide(III) Nitrate Complexes with Terdentate ONO Donor Hydrazone Derived from 2-Benzimidazolyl Mercaptoaceto Hydrazide and o-Hydroxy Aromatic Aldehyde

2011 ◽  
Vol 8 (4) ◽  
pp. 1900-1910 ◽  
Author(s):  
Vinayak M. Naik ◽  
Nirmalkumar B. Mallur
Keyword(s):  
Metal Ion ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Hydrazone Ligand ◽  
Keto Form ◽  
Thermal Stabilities ◽  
H Nmr ◽  
Uv Visible ◽  
Nitrate Complexes

A few eight coordinated complexes of lanthanide(III) nitrate with 2-benzimidazolyl mercaptoaceto hydrazone ligand (LH2) with the general formula [Ln(LH)2NO2]H2O (where Ln = La, Pr, Nd, Sm and Gd) have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, UV-Visible, IR and1H NMR spectral studies. The experimental data sustain stoichiometry of 1:2 (metal/ligand) for the complexes. The spectral data shows that the ligand reacts in keto form and behaves as monobasic terdentate in nature. The nitrate appears to coordinate in the bidentate fashion to the metal ion. The thermal stabilities of the complexes have been studied by TGA and their kinetic parameters were calculated using Coats-Redfern and MKN methods. The antimicrobial activity studies have been under taken and results are discussed.

Synthesis and Characterization of New Triazole Ligand with Some Transition Metals

2021 ◽  
Vol 19 (7) ◽  
pp. 137-143
Author(s):  
Maream Mamoon ◽  
Suad T. Saad ◽  
Nour Abd Alrazzak
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Visible Spectrum ◽  
Synthesis And Characterization ◽  
Divalent Metal Ions ◽  
Cobalt Nickel ◽  
Nickel Copper ◽  
Atomic Absorption Technique ◽  
Uv Visible

The work includes synthesis and characterization of new ligand and its complexes with divalent metal ions such as cobalt, nickel, copper and zinc. This project includes firstly, the synthesis of Schiff base by reacting P-aminoacetophenone with 2-amino-6-methylpyridine by the reflux reaction for 6 hr. and at 70 ° C. The second step involves the synthesis azo-Schiff base containing ligand which was prepared by the reaction of the Schiff base with the heterocyclic 1,2,4-triazole. The prepared ligand was characterized using spectroscopic methods such as Infrared spectrum, UV-visible spectrum, 1HNMR and 13CNMR spectrum. In the third step, the ligand complexes were prepared by the reaction between the ligand and the metal ion salts to obtain the related metal complex. Some properties of the prepared compounds were studied such as the solubility. The prepared complexes were characterized using IR spectroscopy, UV-Visible, conductivity, magnetic sensitivity, and the atomic absorption technique was used to determine the percentage of each metal in its complex.

scholarly journals Preparation and Characterization of bis (4-methoxyanilinium) tetrachlorozincate

2014 ◽  
Vol 10 (3) ◽  
pp. 2355-2362
Author(s):  
H. Rahmouni ◽  
W. Smirani Sta ◽  
M. Rzaigui
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Van Der Waals Interactions ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Layers ◽  
Dimensional Network ◽  
Uv Visible

A new zinc complex of formula [C7H10NO]2 ZnCl4 has been prepared and characterized by X-ray diffraction,  IR and UV-Visible spectroscopies. The complex crystallizes in the monoclinic space group P21/n with a minimal tetrahedral distortion of the ZnCl42- ion and with lattice parameters: a =12.054 (2) Å, b =7.129 (3) Å, c =23.480 (2) Å, β = 100.67 (2)°, V = 1983.03 (1) Å3 and Z = 4. The crystal structure was solved and refined to R = 0.080 and RW = 0.227 with 9611 independent reflections. It can be described by organic layers of p-anisidinium cations held together by C-H…O hydrogen bonds parallel to (010) plane, linked to the inorganic groups of ZnCl42- anions through N-H…Cl hydrogen bonds, electrostatic and Van Der Waals interactions, to form a three-dimensional network.

scholarly journals Crystal structure and spectroscopic analysis of a new oxalate-bridged MnIIcompound:catena-poly[guanidinium [[aquachloridomanganese(II)]-μ2-oxalato-κ4O1,O2:O1′,O2′] monohydrate]

2016 ◽  
Vol 72 (5) ◽  
pp. 724-729 ◽  
Author(s):  
Hiba Sehimi ◽  
Ichraf Chérif ◽  
Mohamed Faouzi Zid
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Spectroscopic Analysis ◽  
Structural Data ◽  
Compound A ◽  
Distorted Octahedral Coordination ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral ◽  
Uv Visible

As part of our studies on the synthesis and the characterization of oxalate-bridged compoundsM–ox–M(ox = oxalate dianion andM= transition metal ion), we report the crystal structure of a new oxalate-bridged MnIIphase, {(CH6N3)[Mn(C2O4)Cl(H2O)]·H2O}n. In the compound, a succession of MnIIions (situated on inversion centers) adopting a distorted octahedral coordination and bridged by oxalate ligands forms parallel zigzag chains running along thecaxis. These chains are interconnected through O—H...O hydrogen-bonding interactions to form anionic layers parallel to (010). Individual layers are held togetherviastrong hydrogen bonds involving the guanidinium cations (N—H...O and N—H...Cl) and the disordered non-coordinating water molecule (O—H...O and O—H...Cl), as well as by guanidinium π–π stacking. The structural data were confirmed by IR and UV–Visible spectroscopic analysis.

Synthesis and Characterization of Complexes of New Derivative of Cyclopentaphenanthren-3-one with Manganese (II), Iron (II), Cobalt (II), Nickel (II), and Copper (II) Ions

2020 ◽  
Vol 38 (3B) ◽  
pp. 197-203
Author(s):  
Liblab S. Jassim
Keyword(s):  
Metal Ion ◽  
Molar Conductance ◽  
Spectral Measurements ◽  
Chemical Preparation ◽  
Electron Pairs ◽  
H Nmr ◽  
Absorption Studies ◽  
Ft Ir ◽  
Uv Visible

This work involves the chemical preparation from a series of metal Complexes having the general composition M(L)2(H2O)2, where M = [Mn+2, Fe+2, Co+2, Ni+2 and Cu+2]. The ligand used was 9-fluoro-17-(1-hydrazono-2-hydroxyethyl)-11,17-dihydroxy-10,13,16-trimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[α]phenanthren-3-one (FHDTCP), who was diagnosed by H-NMR spectra. These complexes have been prepared and characterized by the ligand to metal by molar conductance, spectral (UV-Visible and FT-IR), and atomic absorption studies. The IR spectral measurements forecast interference to oxygen, nitrogen in coordination from the electron pairs to the metal ion in the center. And suggested the complexes geometry be octahedral for all.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

convergent-beam diffraction from surfaces

1987 ◽  
Vol 45 ◽  
pp. 30-33
Author(s):  
J. A. Eades ◽  
A. E. Smith ◽  
D. F. Lynch
Keyword(s):  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Plane Figure ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Patterns ◽  
Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

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