scholarly journals Tetramer Compound of Manganese Ions with Mixed Valence [MnII MnIII MnIV] and Its Spatial, Electronic, Magnetic, and Theoretical Studies

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 447 ◽  
Author(s):  
Cándida Pastor-Ramírez ◽  
Rafael Ulloa ◽  
Daniel Ramírez-Rosales ◽  
Hugo Vázquez-Lima ◽  
Samuel Hernández-Anzaldo ◽  
...  
Keyword(s):  
Mixed Valence ◽  
Magnetic Behavior ◽  
Local Geometry ◽  
Spectroscopic Techniques ◽  
Theoretical Studies ◽  
The Novel ◽  
Manganese Ions ◽  
Computational Calculations ◽  
Valence Electrons ◽  
Coordination Reaction

Using different spectroscopic techniques and computational calculations, we describe the structural and electromagnetic relationship that causes many interesting phenomena within a novel coordination compound with mixed valence manganese (II, III and IV) in its crystal and powder state. The novel compound [MnII MnIII MnIV(HL)2(H2L)2(H2O)4](NO3)2(H2O) 1 was obtained with the Schiff base (E)-2-((2-hydroxybenzylidene)amine)-2-(hydroximethyl)propane-1,3-diol, (H4L), and Mn(NO3)2.4H2O. The coordination reaction was promoted by the deprotonation of the ligand by the soft base triethylamine. The paper’s main contribution is the integration of the experimental and computational studies to explain the interesting magnetic behavior that the mixed valence manganese multimetallic core shows. The results presented herein, which are rarely found for Mn(II), (III) and (IV) complexes, will contribute to the understanding of the magnetic communication generated by the valence electrons and its repercussion in the local geometry and in the overall crystalline structure.

Bleispezies PbX und PbX2 als Brückenliganden in übergangsmetallorganisch geschützten Koordinationsverbindungen/ Leadspecies PbX and PbX2 as Bridging Ligands in Organometallic Protected Coordination Compounds

2002 ◽  
Vol 57 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Peter Rutsch ◽  
Gottfried Huttner
Keyword(s):  
Coordination Compounds ◽  
Dynamic Behaviour ◽  
Disodium Salt ◽  
3D Nmr ◽  
Spectroscopic Techniques ◽  
The Novel ◽  
Bridging Ligands ◽  
X Ray ◽  
Nmr Data ◽  
First Time

The disodium salt Na2[{(CO)5Cr}2Pb(NO3)2], Na2·1, which contains a lead center in a (4+2) coordination mode, reacts with tetraphenylphosphonium halides [Ph4P]X to give the tetrahedral compounds [Ph4P]2[{(CO)5Cr}2PbX2] (X = Cl: 2a; X = Br: 2b; X = I: 2c). Substitution of the nitrate groups of Na2·1 by alcoxides leads to binuclear compounds of the type [{(CO)5Crg2Pb(μ2-OR)2Pb{Cr(CO)5}2]2- (R = Et: 3a; R = n -Pr: 3b; R = i-Pr: 3c; R = Allyl: 3d). NMR experiments show that these dimeric compounds are in equilibrium with the monomeric species [{(CO)5Cr}2PbR]- .Trialkylphosphanes react with Na2·1 to give the neutral phosphane complexes [{(CO)5Cr}2Pb(PR3)2] (R=Me: 4a; R=Et: 4b; R = n-Bu: 4c), which show dynamic behaviour in solution. All of the novel compounds have been characterized by X-ray analysis, as well as by the usual analytic and spectroscopic techniques. 207Pb-NMR data of Cr(CO)5- bound lead species are reported for the first time.

scholarly journals Graphene oxide chemically decorated with hybrid Ag-Ru/chitosan nanoparticles: fabrication and properties

2015 ◽  
Author(s):  
Murugan Veerapandian ◽  
Suresh Neethirajan
Keyword(s):  
Graphene Oxide ◽  
Chitosan Nanoparticles ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Techniques ◽  
Wet Chemical ◽  
Amine Groups ◽  
Oxygenated Functional Groups ◽  
Coordination Reaction

Hybridization of distinct materials into a single nanoplatform is relevant to advance material’s properties for functional application such as biosensor platform. We report the synthesis and characterization of nanosheets of graphene oxide decorated with hybrid nanoparticles of silver-ruthenium bipyridine complex (Ag@[Ru(bpy)3]2+) core and chitosan shell. Hybrid nanoparticles were first obtained through a sequential wet-chemical approach using in situ reduction, electrostatic and coordination reaction. Oxygenated functional groups of graphene oxide and abundant amine groups of chitosan layer on the surface of hybrid nanoparticles allowed the functionalization reaction. Changes in intrinsic optical, chemical and structural properties of graphene oxide due to hybrid nanoparticles were studied in depth using spectroscopic techniques and an electron microscope. Electrodes modified with nanosheets of graphene oxide-hybrid nanoparticles retain the biocompatibility and displayed an amplified redox property suitable for a broad range of sensing studies.

The novel silicide Eu3Si4: structure, chemical bonding, magnetic behavior and electrical resistivity

2004 ◽  
Vol 177 (6) ◽  
pp. 2115-2121 ◽  
Author(s):  
Franz Weitzer ◽  
Yurii Prots ◽  
Walter Schnelle ◽  
Kurt Hiebl ◽  
Yuri Grin
Keyword(s):  
Electrical Resistivity ◽  
Chemical Bonding ◽  
Magnetic Behavior ◽  
The Novel

Synthesis and characterization of a uranium oxide hydrate framework with Sr(II) ions: Structural insights and mixed uranium valences

2022 ◽  
Author(s):  
Kim Lu ◽  
Yingjie Zhang ◽  
Tao Wei ◽  
Timothy Ablott ◽  
Thanh Ha Nguyen ◽  
...  
Keyword(s):  
Uranium Oxide ◽  
Mixed Valence ◽  
Synthesis And Characterization ◽  
Monoclinic Space Group ◽  
Spectroscopic Techniques ◽  
Space Group ◽  
Oxide Hydrate ◽  
Structural Insights

A mixed-valence uranium oxide hydrate framework with Sr2+ ions (UOF-Sr2) was synthesized hydrothermally and characterized with multiple structural and spectroscopic techniques. Compound UOF-Sr2 crystallizes in monoclinic space group C2/c, having...

Charge - Ordered Manganeese Oxide Studied By Ω - Filter - Angular Resolved EELS

2001 ◽  
Vol 7 (S2) ◽  
pp. 1146-1147
Author(s):  
Y. Murooka ◽  
N. Tanaka ◽  
M. Hibino ◽  
K. Tsuda ◽  
M. Tanaka
Keyword(s):  
Electronic Structure ◽  
Colossal Magnetoresistance ◽  
Manganese Oxides ◽  
Charge Ordering ◽  
Nanometer Scale ◽  
Theoretical Studies ◽  
Optical Responses ◽  
Column Type ◽  
Valence Electrons ◽  
Electron Energy Loss

Despite of the intensive studies, Colossal Magnetoresistance (CMR) phenomena occurring in manganese oxides is still not fully understood. Theoretical studies based on an ordered crystal phase such as the charge-ordering (CO) phase have shown some successes in reproducing experimental evidences. Recently it was, however, shown that such a CO phase included giant clusters which were as large as 100 nm. This indicates the importance of the nanometer-scale information about the electronic structure to understand the CO. La0.5Sr1.5MnO4 is one of the oxides under intense investigations. in the CO phase, the eg valence electrons were found to be ordered at Mn sites. The optical responses of the CO clusters, however, has not been studied. in this study we have attempted to obtain such information from CO clusters in La0.5Sr1.5MnO4 by angular-resolved electron-energy-loss-spectroscopy (EELS) using an in-column type Ω-spectrometer.

The Constituents of Naucleadiderrichii. Part III. Indole-Pyridine Alkaloids

1972 ◽  
Vol 50 (10) ◽  
pp. 1486-1495 ◽  
Author(s):  
D. G. Murray ◽  
A. Szakolcai ◽  
Stewart McLean
Keyword(s):  
Spectroscopic Techniques ◽  
The Novel ◽  
Working Hypothesis ◽  
Spectroscopic Characteristics ◽  
Form Ring

Six alkaloids isolated from the bark of Naucleadiderrichii have been shown to have structures that contain both indole and pyridine units. Because of the small amounts available of each constituent, investigation of structure has been confined mainly to the application of spectroscopic techniques; these have shown that all of these alkaloids belong to the novel indole-pyridine class, and have led us to propose structures or part structures with varying degrees of confidence for each of the alkaloids. Structure 1 was deduced for naucledine, C18H15N3O2, and confirmed by synthesis. Its spectroscopic characteristics indicate that nauclederine, C19H19N3O2, has structure 3, but this has not yet been confirmed by synthesis. Evidence is presented that nauclechine, C21H21N3O3, has part structures 6 and 7, and it is suggested that these can be incorporated in structure 8. A working hypothesis for the structure of nauclexine, C18H17N3O2, is represented by 9. Two alkaloids, ND-363C, C21H21N3O3, and ND-305B, C19H19N3O, are closely related, the latter being formally derived from the former by removal of a carbomethoxy group; each appears to exist as an equilibratible pair of isomers containing an indolic (substituted β-carboline) and a pyridine part linked together in a manner which may incorporate a spiro carbinolamine ether (as in 12) that can form ring-opened or solvated derivatives in some solvents.

scholarly journals Contributions to the stereochemistry of zirconium oxysalts—part III: syntheses and crystal structures of M2+Zr(SO4)3 with M = Mg, Mn, Co, Ni, Zn and Cd, and a note on (Fe3+,2+,Zr)2(SO4)3 and Fe2(SO4)3

2019 ◽  
Vol 150 (11) ◽  
pp. 1877-1892
Author(s):  
Gerald Giester ◽  
Dominik Talla ◽  
Manfred Wildner
Keyword(s):  
Mixed Valence ◽  
Structure Type ◽  
Minor Amount ◽  
The Novel ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
A Minor ◽  
Zirconium Oxysalts ◽  
Oxygen Bond

Abstract The novel compounds M2+Zr(SO4)3 with M = Mg, Mn, Co, Ni, Zn, and Cd as well as (Fe3+,2+,Zr)2(SO4)3 were synthesized at mild hydrothermal conditions (Teflon-lined stainless steel vessels, 220 °C) from the mixtures of Zr2O2(CO3)(OH)2, the respective M2+(SO4)·nH2O hydrated salts, H2SO4 and a minor amount of water. Crystals up to several tenths of a mm in size were obtained within a few days and studied at 200 K by single-crystal X-ray diffraction techniques. All these compounds belong to the structure type of monoclinic Fe2(SO4)3; they are either isotypic in space group P21/n (No. 14), Z = 4, i.e. M2+Zr(SO4)3 with M = Mn, Co, Ni, Zn, and Cd as well as the mixed valence sulfate (Fe3+,2+,Zr)2(SO4)3 or in the case of MgZr(SO4)3, closely related but with a larger unit cell, in space group Pc and Z = 8. The framework of the monoclinic Fe2(SO4)3 structure is characterized by two types of isolated Fe3+O6 octahedra, corner-linked with three types of sulfate groups. In the isotypic M2+Zr(SO4)3 series, the Fe3+ atom on the Fe(1) position is substituted by Zr4+ while M2+ ions occupy the Fe(2) site in the ferric sulfate structure type. Mean cation-oxygen bond lengths (S[4]: 1.462–1.472 Å; Zr[6]: 2.053–2.060 Å as well as M2+–O distances) are generally rather short, but still within the range reported in literature. Graphic abstract

ChemInform Abstract: Synthesis and Structure of the Novel Heptanuclear Oxonitro Complex of Platinum with Mixed Valence K8((O2N)6Pt(II)3(μ-O)3Pt(IV)(μ-O)3Pt( II)3(NO2)6)×7 H2O.

ChemInform ◽  
2010 ◽  
Vol 22 (26) ◽  
pp. no-no
Author(s):  
V. V. LAPKIN ◽  
M. D. SURAZHSKAYA ◽  
L. K. SHUBOCHKIN ◽  
T. B. LARINA ◽  
P. A. KOZ'MIN
Keyword(s):  
Mixed Valence ◽  
The Novel
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