A nitronyl nitroxide and its two 1D chain Cu–Tb complexes: synthesis, structures, and magnetic properties

Abstract

A new nitronyl nitroxide, namely NIT-Ph-<i>p</i>-OCH₂trz (1), and two types of one-chain Cu-Tb complexes, namely [TbCu(hfac)₅NIT-Ph-<i>p</i>-OCH₂trz·0.5C₆H₁₄] _<i>n</i> (2a) and [LnCu(hfac)₅NIT-Ph-<i>p</i>-OCH₂trz] _<i>n</i> (2b) (NIT-Ph-<i>p</i>-OCH₂trz = 2-(4-((1<i>H</i>-1,2,4-triazol-1-yl)methoxy)phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac = hexafluoroacetylacetonate), have been successfully synthesized simultaneously through reacting nitronyl nitroxide radical NIT-Ph-<i>p</i>-OCH₂trz with Cu(hfac)₂ and Ln(hfac)₃, and the molecular structures have been elucidated <i>via</i> single-crystal X-ray structural analysis. 2a features a 'ladder-like' chain structure, while 2b displays a linear chain structure built up by Ln(hfac)₃ units bridged with the NO groups of radical ligands. The additional Cu(ii) ions are coordinated to the nitrogen atoms of the triazole units. Nonzero out-of-phase signals are observed for the Tb derivatives (2a and 2b) and they exhibit frequency-dependent out-of-phase signals indicating a single-chain magnet behavior.