ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Pentanuclear heterobimetallic 3d-4f complexes of Ln₂M₃-type — structure and magnetism

Matthias Siebold, Maria Korabik, Uwe Schilde, Jerzy Mrozinski, and Peter Strauch

Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D 14476 Golm, Germany

E-mail: ps@chem.uni-potsdam.de

Received: 30 October 2007  Revised: 22 February 2008  Accepted: 4 March 2008

Abstract: From a series of pentanuclear, heterobimetallic complexes of the general composition [{Ln(H₂O)_n}₂{Ni(dto)₂}₃] · xH₂O, four complexes (Ln = Gd(III) with n = 4; Ln = Dy(III), Ho(III), or Er(III), with n = 5; x = 9–12; dto = 1,2-dithiooxalate) were studied due to their large magnetic moments (up to 14.65 B.M.). The magnetic properties of these complete series were measured at room temperature and the temperature dependent magnetic properties of the complexes Gd₂Ni₃, Dy₂Ni₃, Ho₂Ni₃, and Er₂Ni₃ were studied at room temperature down to 1.8 K. Whereas the intramolecular metal-metal distances were rather long (Ni1-Ni2: 11.0–11.5 Å; Ln-Ni: 6.0–6.3 Å), relatively short intermolecular metal-metal distances (Ni1-Ni2′: 3.5 Å; Er-Er′: 6.0 Å) were found in the crystal lattice, giving rise to weak intermolecular metal-metal interactions. These weak spin interactions were also supported by the EPR spectrum of a powdered sample of the diamagnetically undiluted Gd₂Ni₃ complex.

Keywords: lanthanides - 1,2-dithiooxalate - crystal structure - nickel(II) - magnetic susceptibility

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-008-0060-9

Chemical Papers 62 (5) 487–495 (2008)