Fluorinated alkoxides. Part XIII. The reduction of β-imino-alkoxy complexes to give stable, polydentate, amino-alcohols; their coordination to Co2+, Ni2+, and Cu2+

1978 ◽  
Vol 56 (23) ◽  
pp. 2966-2969 ◽  
Author(s):  
John W. L. Martin ◽  
C. J. Willis
Keyword(s):  
Metal Atom ◽  
Amino Alcohols ◽  
Fluorinated Alcohol ◽  
Fluorinated Alkoxides

The amino-alcohols HOC(CF3)2CH2CH(CH3)NH(CH2)3NHCH(CH3)CH2C(CF3)2OH and HOC(CF3)2CH2CH(CH3)NH(CH2)3NH(CH2)3NHCH(CH3)CH2C(CF3)2OH have been prepared by reduction of the corresponding imino-alcohols coordinated to, e.g., Cu2+, by use of LiAlH4. The products are capable of acting as polydentate, dinegative, ligands (following ionization of the fluorinated alcohol groups) and the second compound gives stable, neutral, complexes of Co2+, Ni2+, and Cu2+ in which the metal atom is five-coordinate.

Fluorinated alkoxides. Part XI. Studies on highly fluorinated amino-alcohols and their metal derivatives

1977 ◽  
Vol 55 (13) ◽  
pp. 2465-2472 ◽  
Author(s):  
In-Soon Chang ◽  
Christopher J. Willis
Keyword(s):  
Donor Site ◽  
Amino Alcohols ◽  
Formation Constants ◽  
Intramolecular Proton Transfer ◽  
Nitrogen Donor ◽  
Metal Derivatives ◽  
Fluorinated Alcohol ◽  
Fluorinated Alkoxides ◽  
Trifluoromethyl Groups ◽  
Steric Influence

We describe the synthesis of a number of difunctional molecules in which the fluorinated tertiary alcohol grouping, -C(CF3)20H, is combined with a nitrogen donor site such as an amino-group or a pyridine ring. In all cases, zwitterionic behaviour in solution is found resulting from intramolecular proton transfer from the acidic fluorinated alcohol to the nitrogen, and this sometimes persists in the solid state, e.g. NH2CH2CH2C(CF3)20H exists as the dipolar ion +NH3CH2CH2C(CF3),0-. Measurements of pK values suggest that the behaviour of the fluorinated amino-alcohols may be compared with that of the amino-acids, subject to changes to be expected from the lower acidity of the -C(CF3)20H group. Metal complexes of the fluorinated amino-alcohols form readily; specifically, neutral complexes of Co2+, Ni2+, and Cu2+ of formula M(L),, where L is an ionized amino-alcohol chelating through the ionized hydroxy group and the nitrogen atom. Measurements of formation constants show that the six-membered chelate rings are the most stable, while a comparison of the stabilities of fluorinated amino-alkoxy complexes with those of analogous aminoacids shows that the former are less stable: this is attributed to the steric influence of the trifluoromethyl groups.

Fluorinated alkoxides. Part XII. Studies on potentially tridentate fluorinated diols; zwitterionic and five-coordinate complexes of Ni2+ and Cu2+

1978 ◽  
Vol 56 (17) ◽  
pp. 2369-2373 ◽  
Author(s):  
Stephen J. Loeb ◽  
John W. L. Martin ◽  
Christopher J. Willis
Keyword(s):  
Steric Effects ◽  
Bidentate Ligands ◽  
Tridentate Ligands ◽  
The Third ◽  
Complexing Ability ◽  
Fluorinated Alcohol ◽  
Fluorinated Alkoxides

The complexing ability towards Ni2+ and Cu2+ of the potentially tridentate ligands HOC(CF3)2CH2C(O)CH2C(CF3)2OH, HOC(CF3)2CH2CH(OH)CH2C(CF3)2OH, and HOC(CF3)2CH2CH2N:C(CH3)CH2C(CF3)2OH has been studied. The first two act as bidentate ligands, uninegative or dinegative according to the extent of ionization of the fluorinated alcohol groups; when both were ionized, the complexes had a zwitterionic structure. The third ligand was exclusively tridentate in its complexes; this difference is ascribed to its greater flexibility. Both four- and five-coordinate complexes of nickel were observed, the latter being produced either by choice of co-ligands or by solvation, but no six-coordinate complex was formed in this series. Limitations on coordination for the metal are ascribed to steric effects.

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.

Potent neuroleptic agents: Some new amino alcohols of the 10-piperazinodibenzo[b,f]thiepin series and their derivatives

1976 ◽  
Vol 41 (2) ◽  
pp. 443-458 ◽  
Author(s):  
J. O. Jílek ◽  
I. Červená ◽  
Z. Kopicová ◽  
K. Šindelář ◽  
E. Svátek ◽  
...  
Keyword(s):  
Amino Alcohols
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