Magnetic Properties of Diruthenium(II,III) Carboxylate Compounds with Large Zero-Field Splitting and Strong Antiferromagnetic Coupling

2001 ◽  
Vol 40 (4) ◽  
pp. 613-619 ◽  
Author(s):  
R. Jiménez-Aparicio ◽  
F. A. Urbanos ◽  
J. M. Arrieta
Keyword(s):  
Magnetic Properties ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting

On the magnetic properties of some haemoglobin complexes

1956 ◽  
Vol 235 (1200) ◽  
pp. 23-36 ◽  
Keyword(s):  
Magnetic Properties ◽  
Iron Atom ◽  
Thermal Equilibrium ◽  
Oxygen Molecule ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Theoretical Scheme ◽  
Inorganic Complexes

Most haemoglobin compounds fall satisfactorily into Pauling’s classification of ‘ionic’ and ‘covalent’ complexes. A few, however, have surprising magnetic properties. In this paper interpretations of these properties are offered which enable all the compounds to be fitted into a theoretical scheme of the type which is adequate for an approximate understanding of simple inorganic complexes. In particular, it is suggested that: the oxygen molecule in oxyhaemoglobin is not at right angles to the haem but probably parallel to it; all ferrihaemoglobin derivatives have a spin of either S = ½ or S = 5/2 at each iron atom or, in the case of ferrihaemoglobin hydroxide, are a thermal equilibrium of the two; ferrihaemoglobin derivatives with S = 5/2 have usually or always a large zero-field splitting, the lowest states being characterized by S ᴟ = ± ½ perpendicular to the haem.

Antiferromagnetism and metamagnetism in 1,4-diazine and pyridine complexes of nickel(II)

1995 ◽  
Vol 73 (2) ◽  
pp. 275-283 ◽  
Author(s):  
Tom Otieno ◽  
Robert C. Thompson
Keyword(s):  
Magnetic Properties ◽  
Electronic Spectroscopy ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Critical Fields ◽  
Scanning Calorimetry ◽  
Magnetic Exchange ◽  
Nickel Ions ◽  
Pyridine Complexes

Several nickel(II) complexes containing pyridine (py), pyrazine (pyz) or methylpyrazine (mepyz) have been synthesized and characterized by vibrational and electronic spectroscopy, differential scanning calorimetry, and magnetic susceptibility studies to cryogenic temperatures. A comparison of the magnetic properties of the polymeric diazine-bridged complexes, Ni(pyz)2X2 (X = Cl or NO3), Ni(pyz)(p-CH3C6H4SO3)2, Ni(mepyz)(NO3)2, and Ni(pyz)3(CH3SO3)2•CH3OH with those of the related monometallic systems, Ni(py)4X2 (X = Cl, p-CH3C6H4SO3 or CH3SO3) and Ni(mepyz)4(NO3)2•H2O provides evidence for weak antiferromagnetic coupling between metal centers mediated by bridging diazine ligands in the former group of compounds. The magnetic properties were analyzed employing a model for S = 1 which takes into account zero-field splitting and employs a molecular field term to account for weak magnetic exchange. The compounds Ni(pyz)Cl2 and Ni(py)Cl2 show metamagnetic behaviour with critical fields of 13 and 2 kOe, respectively, at 2 K. In these compounds nickel ions, linked in chains by bridging chlorides, exhibit intrachain ferromagnetic and interchain antiferromagnetic exchange. In Ni(pyz)Cl2 bridging pyrazine ligands are considered to provide the pathway for the antiferromagnetic coupling resulting in a high critical field. Keywords: nickel(II), pyrazine, pyridine, complexes, metamagnetism, antiferromagnetism.

Correlating the axial Zero Field Splitting with the slow magnetic relaxation in GdIII SIMs

2021 ◽  
Author(s):  
Júlia Mayans ◽  
Albert Escuer
Keyword(s):  
Magnetic Relaxation ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Slow Magnetic Relaxation

A possible relation between the value of the axial Zero Field Splitting and the occurrence of field-induced slow magnetic relaxation has been established for a new gadolinium(iii) compound.

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