Self-Assembled Transition-Metal Macrocycles and Two-Dimensional Coordination Polymers Derived from Flexible C2Co2Cluster-Bridged Bipyridine Ligands [(4-C5H4NCO2CH2)2C2Co2(CO)6] and [(3-C5H4NCO2CH2)2C2Co2(CO)6]

2009 ◽  
Vol 2009 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Li-Cheng Song ◽  
Guo-Xia Jin ◽  
Li-Qun Zhao ◽  
Hu-Ting Wang ◽  
Wen-Xiong Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Coordination Polymers ◽  
Two Dimensional ◽  
Self Assembled

scholarly journals Zn and Ni complexes of pyridine-2,6-dicarboxylates: crystal field stabilization matters!

2019 ◽  
Vol 75 (6) ◽  
pp. 903-911
Author(s):  
Marius Kremer ◽  
Ulli Englert
Keyword(s):  
Transition Metal ◽  
Dicarboxylic Acid ◽  
Crystal Field ◽  
Coordination Polymers ◽  
Two Dimensional ◽  
Reaction Products ◽  
Coordination Polyhedra ◽  
Trigonal Bipyramidal ◽  
Regular Shape ◽  
Coordination Spheres

Six reaction products of ZnII and NiII with pyridine-2,6-dicarboxylic acid (H2Lig1), 4-chloropyridine-2,6-dicarboxylic acid (H2Lig2) and 4-hydroxypyridine-2,6-dicarboxylic acid (H2Lig3) are used to pinpoint the structural consequences of crystal field stabilization by an incomplete d shell. The pseudo-octahedral ZnII coordination sphere in bis(6-carboxypicolinato)zinc(II) trihydrate, [Zn(C7H4NO4)2]·3H2O or [Zn(HLig1)2]·3H2O, (1), is significantly less regular than that about NiII in the isostructural compound bis(6-carboxypicolinato)nickel(II) trihydrate, [Ni(C7H4NO4)2]·3H2O or [Ni(HLig1)2]·3H2O, (2). The ZnII complexes poly[(4-chloropyridine-2,6-dicarboxylato)zinc(II)], [Zn(C7H2ClNO4)] n or [Zn(Lig2)] n , (3), and poly[[(4-hydroxypyridine-2,6-dicarboxylato)zinc(II)] monohydrate], {[Zn(C7H3NO5)]·H2O} n or {[Zn(Lig3)]·H2O} n , (4), represent two-dimensional coordination polymers with chelating and bridging pyridine-2,6-dicarboxylate ligands in which the coordination polyhedra about the central cations cannot be associated with any regular shape; their coordination environments range between trigonal–bipyramidal and square-pyramidal geometries. In contrast, the corresponding adducts of the diprotonated ligands to NiII, namely triaqua(4-chloropyridine-2,6-dicarboxylato)nickel(II), [Ni(C7H2ClNO4)(H2O)3] or [NiLig2(OH2)3)], (5), and triaqua(4-hydroxypyridine-2,6-dicarboxylato)nickel(II) 1.7-hydrate, [Ni(C7H3NO5)(H2O)3]·1.7H2O or [NiLig3(OH2)3)]·1.7H2O, (6), feature rather regular octahedral coordination spheres about the transition-metal cations, thus precluding the formation of analogous extended structures.

Electronic properties of quasi two-dimensional transition metals chalcogenides with low-dimensional magnetism

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 87-95
Author(s):  
M. S. Baranava ◽  
P. A. Praskurava
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Exchange Interaction ◽  
Electronic Properties ◽  
Metal Atom ◽  
Transition Metal Atom ◽  
Two Dimensional ◽  
Transition Metal Atoms ◽  
Ground Magnetic ◽  
Low Dimensional

The search for fundamental physical laws which lead to stable high-temperature ferromagnetism is an urgent task. In addition to the already synthesized two-dimensional materials, there remains a wide list of possible structures, the stability of which is predicted theoretically. The article suggests the results of studying the electronic properties of MAX3 (M = Cr, Fe, A = Ge, Si, X = S, Se, Te) transition metals based compounds with nanostructured magnetism. The research was carried out using quantum mechanical simulation in specialized VASP software and calculations within the Heisenberg model. The ground magnetic states of twodimensional MAX3 and the corresponding energy band structures are determined. We found that among the systems under study, CrGeTe3 is a semiconductor nanosized ferromagnet. In addition, one is a semiconductor with a bandgap of 0.35 eV. Other materials are antiferromagnetic. The magnetic moment in MAX3 is localized on the transition metal atoms: in particular, the main one on the d-orbital of the transition metal atom (and only a small part on the p-orbital of the chalcogen). For CrGeTe3, the exchange interaction integral is calculated. The mechanisms of the formation of magnetic order was established. According to the obtained exchange interaction integrals, a strong ferromagnetic order is formed in the semiconductor plane. The distribution of the projection density of electronic states indicates hybridization between the d-orbital of the transition metal atom and the p-orbital of the chalcogen. The study revealed that the exchange interaction by the mechanism of superexchange is more probabilistic.

scholarly journals Visualization of Multifractal Superconductivity in a Two-Dimensional Transition Metal Dichalcogenide in the Weak-Disorder Regime

Nano Letters ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 5111-5118 ◽  
Author(s):  
Carmen Rubio-Verdú ◽  
Antonio M. Garcı́a-Garcı́a ◽  
Hyejin Ryu ◽  
Deung-Jang Choi ◽  
Javier Zaldı́var ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Dichalcogenide ◽  
Two Dimensional ◽  
Weak Disorder

scholarly journals Super-resolved Optical Mapping of Reactive Sulfur-Vacancies in Two-Dimensional Transition Metal Dichalcogenides

ACS Nano ◽  
2021 ◽  
Author(s):  
Miao Zhang ◽  
Martina Lihter ◽  
Tzu-Heng Chen ◽  
Michal Macha ◽  
Archith Rayabharam ◽  
...  
Keyword(s):  
Transition Metal ◽  
Optical Mapping ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
Metal Dichalcogenides
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