Synthesis and Selected Properties of New Complex Cation Decorated Polyoxotantalates

2021 ◽  
Author(s):  
Dana-Céline Krause ◽  
Sebastian Mangelsen ◽  
Christian Näther ◽  
Wolfgang Bensch
Keyword(s):  
Complex Cation

Coadsorption of bulky ions by surfactants. Monomolecular layers of tris(2,2'-bipyridyl)ruthenium(II) complex with sodium lauryl sulphate on glassy carbon, platinium, n-SnO2, and n-Si electrodes

1984 ◽  
Vol 49 (10) ◽  
pp. 2187-2196 ◽  
Author(s):  
Jan Lasovský ◽  
František Grambal ◽  
Miroslav Rypka
Keyword(s):  
Glassy Carbon ◽  
Complex Cation ◽  
Radiant Energy ◽  
Electric Energy ◽  
Sodium Lauryl Sulphate ◽  
Surface Films ◽  
Order Of Magnitude ◽  
Monomolecular Layers ◽  
Self Association ◽  
Semiconductor Electrodes

The electrochemical and photochemical behaviour of tris(2,2'-bipyridyl)ruthenium(II) complex (I) on glassy carbon, platinium, n-SnO2, and n-Si electrodes in the presence of sodium lauryl sulphate (II) was investigated. The surfactant in low concentrations induces self-association of the complex cation and its accumulation in the electrode-solution interface. At the optimum concentrations of sodium lauryl sulphate (cII ~0.6 mmol l-1) and of the complex (cI < 0.1 mmol l-1), monomolecular layers composed of I, II counterions are formed on the electrodes. The formation of the surface films does not depend on the kind of the electrode and improves the sensitivity of the voltammetric determination of I by as much as an order of magnitude. For the semiconductor electrodes, the surface films enhance the efficiency of conversion of radiant energy into electric energy. The effect under study may participate in the photosynthesis of green plants.

Homoleptic 2,2′-bipyridine metalates(–I) of iron and cobalt, one cocrystallized with an anthracene radical anion and the other with neutral anthracene

2014 ◽  
Vol 70 (8) ◽  
pp. 828-832
Author(s):  
William W. Brennessel ◽  
John E. Ellis
Keyword(s):  
Radical Anion ◽  
Complex Cation ◽  
Solvent Molecule ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Aromatic Donor ◽  
Donor Acceptor ◽  
Anthracene Molecule ◽  
Packing Arrangement ◽  
Solvent Molecules

Homoleptic 2,2′-bipyridine (bipy) metalates of iron and cobalt have been synthesized directly from the corresponding homoleptic anthracene metalates. In the iron structure, bis[([2.2.2]cryptand)potassium(I)] tris(2,2′-bipyridine)ferrate(–I) anthracene(–I), [K(C18H36N2O6)]2[Fe(C10H8N2)3](C14H10), the asymmetric unit contains one potassium complex cation in a general position, the Fe center and one and a half bipy ligands of the ferrate complex on a crystallographic twofold axis that includes the Fe atom, and one half of an anthracene radical anion whose other half is generated by a crystallographic inversion center. The cations and anions are well separated and the geometry about the Fe center is essentially octahedral. In the cobalt structure, ([2.2.2]cryptand)potassium(I) bis(2,2′-bipyridine)cobaltate(–I) anthracene hemisolvate tetrahydrofuran (THF) disolvate, [K(C18H36N2O6)][Co(C10H8N2)2]·0.5C14H10·2C4H8O, the asymmetric unit contains the cation, anion, and both cocrystallized THF solvent molecules in general positions, and one half of a cocrystallized anthracene molecule whose other half is generated by a crystallographic inversion center. The cation and anion are well separated and the ligand planes in the cobaltate anion are periplanar. Each anthracene molecule is midway between and is oriented perpendicular to a pair of symmetry-related bipy ligands such that aromatic donor–acceptor interactions may play a role in the packing arrangement. The lengths of the bonds that connect the bipy rings support the assertion that the ligands are bipy radical anions in the iron structure. However, in the case of cobalt, these lengths are between the known ranges for a bipy radical anion and a bipy dianion, and therefore no conclusion can be made from the crystallography alone. One cocrystallized THF solvent molecule in the cobalt structure was modeled as disordered over three positions with appropriate geometric and thermal restraints, which resulted in a refined component mass ratio of 0.412 (4):0.387 (3):0.201 (3).

Inerte Amminkomplexe als mehrwertige Kationsäuren in wäßriger Lösung / Inert Ammine Complexes as Multivalent Cationic Acids in Aqueous Solution

1980 ◽  
Vol 35 (9) ◽  
pp. 1096-1103 ◽  
Author(s):  
Matthias Kretschmer ◽  
Lutwin Labouvie ◽  
Karl-W. Quirin ◽  
Helmut Wiehn ◽  
Ludwig Heck
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Spectrophotometric Method ◽  
Complex Cation ◽  
Aqua Ligand ◽  
Second Step ◽  
Acidity Constants ◽  
Ammine Complexes ◽  
Temperature Variations ◽  
Enthalpy Changes

Acidity constants of ammine complexes of tetravalent platinum in aqueous solutions have been determined by a spectrophotometric method at very low ionic strengths and extrapolated to zero ionic strength. Temperature variations of pK-values (25 °C and 50 °C) yield thermodynamic parameters for two successive deprotonation steps of hexaammineplatinum(IV), pentaamminechloroplatinum(IV), and tris(ethylenediamine)pla- tinum(IV) complexes and for the deprotonation of pentaammineaquacobalt(III) ion.The enthalpy changes for the first and second steps are similar and range from 50 to 75 kJ/mole while for the aqua ligand of Co(III) 33 kJ/mole are found. The very large dif­ference in the entropy changes (about 70 to 80 J/K mole for the first step and -10 to + 20 J/K mole for the second step) is interpreted by a model of solvation change. The primary hydration sphere of strongly oriented and immobilized water dipoles around the highly charged complex cation is transformed to a hydrogen-bonded solvation sheath when the electric field of the complex is weakened upon release of the first proton.

ChemInform Abstract: Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions.

ChemInform ◽  
2011 ◽  
Vol 42 (50) ◽  
pp. no-no
Author(s):  
Yingying Song ◽  
Huanwang Jing ◽  
Bo Li ◽  
Dongsheng Bai
Keyword(s):  
Ionic Liquids ◽  
Crown Ether ◽  
Complex Cation ◽  
Organic Reactions ◽  
Crown Ether Complex ◽  
Ether Complex

scholarly journals Bis[tetrakis(pyridin-2-yl)methane-κ3N,N′,N′′]cobalt(II) tetrakis(thiocyanato-κN)cobaltate(II) methanol monosolvate

2014 ◽  
Vol 70 (3) ◽  
pp. m96-m97 ◽  
Author(s):  
Yuya Tsunezumi ◽  
Kouzou Matsumoto ◽  
Shinya Hayami ◽  
Akira Fuyuhiro ◽  
Satoshi Kawata
Keyword(s):  
Complex Anion ◽  
Complex Cation ◽  
Solvent Molecule ◽  
Octahedral Geometry ◽  
Title Complex ◽  
Distorted Octahedral Geometry ◽  
Weak Hydrogen Bond ◽  
Tetrahedral Geometry ◽  
Distorted Tetrahedral Geometry ◽  
Distorted Octahedral

The title complex, [Co(C21H16N4)2][Co(NCS)4]·CH3OH, consists of one [Co{C(py)4}2]2+complex cation [C(py)4= tetrakis(pyridin-2-yl)methane], one [Co(NCS)4]2−complex anion and a methanol solvent molecule. In the cation, the CoIIatom is coordinated by six N atoms of two C(py)4ligands in a distorted octahedral geometry. In the anion, the CoIIatom is coordinated by the N atoms of four NCS−ligands in a distorted tetrahedral geometry. The methanol molecule is disordered and was modelled over three orientations (occupancies 0.8:0.1:0.1). There are two weak hydrogen-bond-like interactions between the methanol solvent molecule and NCS−ligands of the anion [O...S = 3.283 (3) and 3.170 (2) Å].

Thermal and light-induced reduction of the ruthenium complex cation Ru(bpy)33+ in aqueous solution

1984 ◽  
Vol 106 (17) ◽  
pp. 4772-4783 ◽  
Author(s):  
Pushpito K. Ghosh ◽  
Bruce S. Brunschwig ◽  
Mei Chou ◽  
Carol Creutz ◽  
Norman Sutin
Keyword(s):  
Aqueous Solution ◽  
Ruthenium Complex ◽  
Complex Cation

scholarly journals Tris(1,10-phenanthroline-κ2 N,N′)cobalt(II) bis(2,4,5-tricarboxybenzoate) monohydrate

IUCrData ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Kai-Long Zhong ◽  
Guo-Qing Cao ◽  
Wei Song ◽  
Chao Ni
Keyword(s):  
Hydrogen Bonds ◽  
Network Structure ◽  
Rotation Axis ◽  
Complex Cation ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Network ◽  
Distorted Octahedral

In the complex cation of the title salt, [Co(C12H8N2)3](C10H5O8)2·H2O, the CoII cation is situated on a twofold rotation axis and is coordinated in a distorted octahedral manner by six N atoms from three chelating 1,10-phenanthroline (phen) ligands. In the crystal, the non-coordinating 2,4,5-tricarboxybenzoate anions interact with each other via O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100). Adjacent sheets are connected by waterO—H...Ocarboxylate hydrogen bonds, resulting in a three-dimensional network structure that surrounds the complex cations.

The melibiose/Na + symporter of Escherichia coli : kinetic and molecular properties

1990 ◽  
Vol 326 (1236) ◽  
pp. 411-423 ◽  
Keyword(s):  
Escherichia Coli ◽  
Complex Cation ◽  
Expression System ◽  
Binding Activity ◽  
Site Directed Mutagenesis ◽  
Coupling Mechanism ◽  
Facilitated Diffusion ◽  
Histidine Residues ◽  
Sugar Binding ◽  
Dependent Transport

The role of the co-transported cation in the coupling mechanism of the melibiose permease of Escherichia coli has been investigated by analysing its sugar-binding activity, facilitated diffusion reactions and energy-dependent transport reactions catalysed by the carrier functioning either as an H + , Na + or Li + -sugar symporter. The results suggest that the coupling cation not only acts as an activator for sugar-binding on the carrier but also regulates the rate of dissociation of the co-substrates in the cytoplasm by controlling the stability of the ternary complex cation-sugar—carrier facing the cell interior. Furthermore, there is some evidence that the membrane potential enhances the rate of symport activity by increasing the rate of dissociation of the co-substrates from the carrier in the cellular compartment. Identification of the melibiose permease as a membrane protein of 39 kDa by using a T7 RNA polymerase/promoter expression system is described. Site-directed mutagenesis has been used to replace individual carrier histidine residues by arginine to probe the functional contribution of each of the seven histidine residues to the symport mechanism. Only substitution of arginine for His94 greatly interferes with the carrier function. It is finally shown that mutations affecting the glutamate residue in position 361 inactivate translocation of the co-substrates but not their recognition by the permease.

A Linear Metal-Metal Bonded Tri-Iron Single-Molecule Magnet

2021 ◽  
Author(s):  
Anandi Srinivasan ◽  
Rebecca A Musgrave ◽  
Mathieu Rouzieres ◽  
Rodolphe Clerac ◽  
John E. McGrady ◽  
...  
Keyword(s):  
Single Molecule ◽  
Complex Cation ◽  
Trinuclear Complex ◽  
Ferromagnetic Coupling ◽  
Single Molecule Magnet ◽  
Metal Metal

The linear trinuclear complex cation [Fe3(DpyF)4]2+ was prepared as [Fe3(DpyF)4](BF4)2·2CH3CN. With large Fe–Fe distances of 2.78 Å, this complex demonstrates intramolecular ferromagnetic coupling between the anisotropic FeII centers (J/kB =...

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