Bis-μ-pyrazolate-Bridged Dinickel(II) and Dicopper(II) Complexes: An Example of Stereoelectronic Preference of Metal Ions and Stabilization of Mixed-Valence NiIIINiII Species

2007 ◽  
Vol 2007 (15) ◽  
pp. 2161-2170 ◽  
Author(s):  
Vibha Mishra ◽  
Francesc Lloret ◽  
Rabindranath Mukherjee
Keyword(s):  
Metal Ions ◽  
Mixed Valence

Investigating reaction conditions for controlling the self-assembly of metal-seamed pyrogallol[4]arene nanocapsules

2019 ◽  
Author(s):  
◽  
Asanka Sajeewani Rathnayake
Keyword(s):  
Metal Ions ◽  
Self Assembly ◽  
Mixed Valence ◽  
Transition Metal Ions ◽  
Ambient Conditions ◽  
Reaction Conditions ◽  
University Of Missouri ◽  
Reduction Reactions ◽  
Oxidation Reduction ◽  
The University

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Upon coordination to metal ions, C-alkylpyrogallol[4]arenes (PgCn, where n is the number of carbon atoms in the pendant alkyl chains), can be assembled into spherical metal-organic nanocapsules (MONCs). MONCs are generally arranged into two different structural types, hexamers and dimers, of which six or two PgCn units assemble into capsular structures by coordination to 24 or 8 metal ions, respectively. Co[II]-, Zn[II]-, and Mn[II]-coordinated MONCs have been synthesized under ambient conditions and structurally characterized. Under certain reaction conditions, some transition metal ions and other reagents seem to act as electron accepting or donating reagents, such that appropriate oxidation or reduction reactions may occur. These types of in-situ redox reactions lead to the formation of mixed-valence Mn[II]/Mn[III]- and Fe[II]/Fe[III]-seamed MONCs. The occurrence of such oxidation/reduction reactions appears to be promoted by certain factors such as resulting pH conditions, size of the coordinating ions/ligands, and oxidizing/reducing abilities of reagents used in each synthesis. In addition, studies have been carried out to incorporate some defects into the MONC outer framework by using mixed-macrocycles as the starting materials. Mixed-macrocycles are synthesized by fusing both resorcinol and pyrogallol into the same macrocycle, and the position of resorcinol units in the MONC usually appears as a hole or defect on the capsule surface. Incorporations of such defects give MONCs potential for, for example, selective filtering of small molecules into the capsule interior and magnetic and electronic applications by varying the electrostatic interaction between adjacent metal ions.

Toward multifunctional molecular cells for quantum cellular automata: exploitation of interconnected charge and spin degrees of freedom

2021 ◽  
Author(s):  
Andrei Palii ◽  
Juan Modesto Clemente Juan ◽  
Andrey Rybakov ◽  
Sergey M. Aldoshin ◽  
Boris Tsukerblat
Keyword(s):  
Cellular Automata ◽  
Metal Ions ◽  
Degrees Of Freedom ◽  
Mixed Valence ◽  
Quantum Cellular Automata ◽  
Paramagnetic Metal

We discuss a possibility to use mixed-valence (MV) dimers comprising paramagnetic metal ions as molecular cells for quantum cellular automata (QCA). Thus, we propose to combine the underlying idea behind...

Divalent metal ions modulated strong frustrated M(ii)–Fe(iii)3O (M = Fe, Mn, Mg) chains with metamagnetism only in a mixed valence iron complex

2015 ◽  
Vol 51 (83) ◽  
pp. 15336-15339 ◽  
Author(s):  
Qi-Long Wu ◽  
Song-De Han ◽  
Qing-Lun Wang ◽  
Jiong-Peng Zhao ◽  
Feng Ma ◽  
...  
Keyword(s):  
Metal Ions ◽  
Mixed Valence ◽  
Magnetic Behaviour ◽  
Iron Complex ◽  
Divalent Metal ◽  
Heterometallic Complexes ◽  
Divalent Metal Ions ◽  
Divalent Ions ◽  
Mixed Valence Complex

Using divalent ions to link the frustrated Fe(iii)3O units two isostructural chains were generated with distinct magnetic behaviour: frustrations and metamagnetism in mixed valence complex, but magnetic frustrations in heterometallic complexes.

Electron Delocalization of Mixed‐Valence Diiron Sites Mediated by Group 10 Metal Ions in Heterotrimetallic Fe‐M‐Fe (M=Ni, Pd, and Pt) Chain Complexes

2018 ◽  
Vol 24 (45) ◽  
pp. 11649-11666 ◽  
Author(s):  
Yu‐Chiao Liu ◽  
Shao‐An Hua ◽  
Ming‐Chuan Cheng ◽  
Li‐Chung Yu ◽  
Serhiy Demeshko ◽  
...  
Keyword(s):  
Metal Ions ◽  
Mixed Valence ◽  
Electron Delocalization ◽  
Chain Complexes ◽  
Group 10

scholarly journals Can Serendipity Still Hold Any Surprises in the Coordination Chemistry of Mixed-Donor Macrocyclic Ligands? The Case Study of Pyridine-Containing 12-Membered Macrocycles and Platinum Group Metal Ions PdII, PtII, and RhIII

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1286
Author(s):  
Alessandra Garau ◽  
Giacomo Picci ◽  
Massimiliano Arca ◽  
Alexander J. Blake ◽  
Claudia Caltagirone ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Metal Ions ◽  
Density Functional ◽  
Mixed Valence ◽  
Platinum Group Metal ◽  
Macrocyclic Ligands ◽  
Octahedral Coordination ◽  
Coordination Environment ◽  
Group Metal ◽  
Platinum Group

This study investigates the coordination chemistry of the tetradentate pyridine-containing 12-membered macrocycles L1-L3 towards Platinum Group metal ions PdII, PtII, and RhIII. The reactions between the chloride salts of these metal ions and the three ligands in MeCN/H2O or MeOH/H2O (1:1 v/v) are shown, and the isolated solid compounds are characterized, where possible, by mass spectroscopy and 1H- and 13C-NMR spectroscopic measurements. Structural characterization of the 1:1 metal-to-ligand complexes [Pd(L1)Cl]2[Pd2Cl6], [Pt(L1)Cl](BF4), [Rh(L1)Cl2](PF6), and [Rh(L3)Cl2](BF4)·MeCN shows the coordinated macrocyclic ligands adopting a folded conformation, and occupying four coordination sites of a distorted square-based pyramidal and octahedral coordination environment for the PdII/PtII, and RhIII complexes, respectively. The remaining coordination site(s) are occupied by chlorido ligands. The reaction of L3 with PtCl2 in MeCN/H2O gave by serendipity the complex [Pt(L3)(m-1,3-MeCONH)PtCl(MeCN)](BF4)2·H2O, in which two metal centers are bridged by an amidate ligand at a Pt1-Pt2 distance of 2.5798(3) Å and feature one square-planar and one octahedral coordination environment. Density Functional Theory (DFT) calculations, which utilize the broken symmetry approach (DFT-BS), indicate a singlet d8-d8 PtII-PtII ground-state nature for this compound, rather than the alleged d9-d7 PtI-PtIII mixed-valence character reported for related dinuclear Pt-complexes.

Faraday Rotation Caused by Mixed Valence Centers in Magnetic Crystals

2010 ◽  
Vol 168-169 ◽  
pp. 541-544
Author(s):  
L.D. Falkovskaya ◽  
Anatoly Yakovlevich Fishman ◽  
Valentin Yakovlevich Mitrofanov ◽  
B.S. Tsukerblat
Keyword(s):  
Metal Ions ◽  
Faraday Rotation ◽  
Electric Dipole ◽  
Mixed Valence ◽  
Double Exchange ◽  
Transition Metal Ions ◽  
Visible Range ◽  
Crystal Fields ◽  
And Migration ◽  
Low Symmetry

The peculiarities of the Faraday rotation in the imperfect garnet-type crystals for which the lattice irregularities are represented by the mixed valence clusters of transition metal ions are analyzed. The model takes into account the cubic and low symmetry crystal fields acting on the metal ions and migration of the “extra” hole. The electric dipole transitions in these types of clusters with migrating hole coupled to the spin core through the double exchange mechanism are shown to lead to a significant magnetooptical activity in the visible range of spectrum. The intensity of these transitions can be comparable or higher than those for the magnetic dipole ones in the same range of frequencies.

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