Nature of the Interaction between LnIII and CuII Ions in the Ladder-Type Compounds {Ln2[Cu(opba)]3}·S (Ln = Lanthanide Element; opba = ortho-Phe

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• 作者：Myrtil L. Kahn ; Corine Mathoni&egrave ; re ; and Olivier Kahn
• 刊名：Inorganic Chemistry
• 出版年：1999
• 出版时间：August 9, 1999
• 年：1999
• 卷：38
• 期：16
• 页码：3692 - 3697
• 全文大小：167K
• 年卷期：v.38,no.16(August 9, 1999)
• ISSN：1520-510X

文摘

To date, most of the studies dealing with the magnetic properties of 4f-3d compounds have been limited to thecase in which the 4f ion was Gd^III, with a pure spin ground state. For the lanthanide(III) ions with a first-orderorbital momentum, the determination of the nature of the 4f-3d interaction is still a challenge. This paper addressesthis problem. The magnetic properties of the compounds of formula {Ln₂[M(opba)]₃}·S (abbreviated hereafter asLn₂M₃) have been investigated; Ln stands for a lanthanide element, M for Cu or Zn, opba for ortho-phenylenebis(oxamato), and S for solvent molecules. All of these compounds have similar one-dimensional structures consistingof ladder-type motifs. Our approach consisted of comparing the magnetic properties of Ln₂Cu₃ and Ln₂Zn₃ foreach Ln^III ion. The former are governed by both the thermal population of the Stark components of Ln^III and theLn^III-Cu^II interaction; the latter are only governed by the thermal population of the Ln^III Stark components. Ithas been confirmed that the Gd^III-Cu^II interaction was ferromagnetic, and it was found that the Tb^III-Cu^II andDy^III-Cu^II interactions were ferromagnetic as well. The Tm^III-Cu^II interaction might also be ferromagnetic; thesituation, however, is uncertain. On the other hand, in all other cases the Ln^III-Cu^II interaction is not ferromagnetic;it is either not detectable by the magnetic technique or antiferromagnetic. The difference between Dy^III-Cu^II(ferromagnetic) and Ho^III-Cu^II (not ferromagnetic) is particularly striking. These findings have been discussed.