Lanthanide–radical linear chain compounds based on 2,4,4,5,5-pentamethylimidazoline-1-oxyl-3-oxide: Structure and magnetic properties

• Published in: Inorganica Chimica Acta Vol. 398; pp. 136 - 140
• Main Authors: Hu, Peng, Zhang, Congming, Gao, Yuanyuan, Li, Yungai, Ma, Yue, Li, Licun, Liao, Daizheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 24.03.2013
• Subjects: Crystal structure; Lanthanide; Nitronyl nitroxide radical; Single-chain magnets; Lanthanide; Single-chain magnets; Nitronyl nitroxide radical; Crystal structure
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2012.12.025

Two new one-dimensional Ln–nitronyl nitroxide complexes with Ln=Y, Dy have been successfully synthesized and characterized. Single crystal X-ray crystallographic analysis reveals that two complexes show similar linear chain structures composed of Ln(hfac)3 units bridged by NITMe radicals through their NO groups. AC magnetic susceptibility studies of Dy complex show slow clear frequency-dependent out-of-phase signals, suggesting a SCM behavior. [Display omitted] ► Two new one-dimensional Ln–radical complexes with Ln=Y, Dy have been prepared. ► The diamagnetic Y ion can mediate weak magnetic coupling between radical ligands. ► The Dy complex exhibits frequency-dependent ac signals indicating SCM behavior. Two one-dimensional nitronyl nitroxide–lanthanide complexes [Ln(hfac)3(NITMe)]n (Ln(III)=Y (1), Dy(2), hfac=hexafluoroacetylacetonate; NITMe=2,4,4,5,5-pentamethylimidazolyl-1-oxyl-3-oxide) have been successfully prepared and characterized. Single crystal X-ray crystallographic analysis reveals that complexes 1 and 2 show similar linear chain structures composed of Ln(hfac)3 units bridged by NITMe radicals through their NO groups. Variable-temperature magnetic susceptibilities of Y complex show that there exists weak antiferromagnetic coupling between the radical ligands through the diamagnetic Y(III) ions. Alternating current (ac) susceptibilities of Dy complex reveal frequency dependent out-of-phase signals, indicating that it behaves as single-chain magnet.