Syntheses, crystal structures, and magnetic properties of RE(III)–Cu(II) heteronuclear complexes with α-methylacrylic acid

Abstract

A series of carboxylate-bridged heteronuclear 3d–4f complexes have been prepared by reaction of REL₃ (HL = CH₂ = C(CH₃)COOH) with Cu(NO₃)₂. A family of air-stable 2-D complexes [RECuL₄(H₂O)₄] _n L _n (RE = La (1), Ce (2), Eu (3), and Gd (4)) have the same crystal system (monoclinic) and space group (P2₁/c). The chains which are made by the carboxylate-bridged alternating Cu(II)–RE(III) fragments spreading along the c-axis are linked through hydrogen bonds by uncoordinated carboxylates to form a 2-D network structure along the bc planes. Magnetic measurements showed that 1 and 2 have antiferromagnetic interaction between RE and Cu, but 4 exhibits ferromagnetic interaction. Eu ions show van Vleck behavior in 3.

Keywords:

• Rare earth
• Copper
• α-Methylacrylic acid
• Crystal structure
• Magnetic property

Acknowledgments

The authors would like to thank the Key Laboratory of Zhejiang University for collecting X-ray data and the Education Committee of Zhejiang Province, China, for providing funds.