Controlled Synthesis of Heterotrimetallic Single‐Chain Magnets from Anisotropic High‐Spin 3 d–4 f Nodes and Paramagnetic Spacers. Issue 1 (7th December 2012)

• Record Type: Journal Article
• Authors: Yao, Min‐Xia; Zheng, Qi; Qian, Kang; Song, You; Gao, Song; Zuo, Jing‐Lin
• Is Part Of: Chemistry. Volume 19:Issue 1(2013)
• Page Start: 294
• Page End: 303
• Publication Date: 2012-12-07
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201203361
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>By using the node‐and‐spacer approach in suitable solvents, four new heterotrimetallic 1D chain‐like compounds (that is, containing 3d–3d′–4f metal ions), {[Ni(L)Ln(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)Fe(Tp*)(CN)<sub>3</sub>]<bold>⋅</bold>2 CH<sub>3</sub>CN<bold>⋅</bold>CH<sub>3</sub>OH}<sub><italic>n</italic></sub> (H<sub>2</sub>L=<italic>N</italic>, <italic>N</italic>′‐bis(3‐methoxysalicylidene)‐1, 3‐diaminopropane, Tp*=hydridotris(3, 5‐dimethylpyrazol‐1‐yl)borate; Ln=Gd (<bold>1</bold>), Dy (<bold>2</bold>), Tb (<bold>3</bold>), Nd (<bold>4</bold>)), have been synthesized and structurally characterized. All of these compounds are made up of a neutral cyanide‐ and phenolate‐bridged heterotrimetallic chain, with a {FeCNNi(OLn)NC}<sub><italic>n</italic></sub> repeat unit. Within these chains, each [(Tp*)Fe(CN)<sub>3</sub>]<sup>−</sup> entity binds to the Ni<sup>II</sup> ion of the [Ni(L)Ln(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)]<sup>+</sup> motif through two of its three cyanide groups in a <italic>cis</italic> mode, whereas each [Ni(L)Ln(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)]<sup>+</sup> unit is linked to two [(Tp*)Fe(CN)<sub>3</sub>]<sup>−</sup> ions through the Ni<sup>II</sup> ion in a <italic>trans</italic> mode. In the [Ni(L)Ln(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)]<sup>+</sup> unit, the Ni<sup>II</sup> and Ln<sup>III</sup> ions are bridged to one other through two phenolic oxygen atoms of the ligand (L). Compounds <bold>1</bold>–<bold>4</bold> are rare examples of 1D cyanide‐ and phenolate‐bridged 3d–3d′–4f helical chain compounds. As expected, strong ferromagnetic interactions are observed between neighboring Fe<sup>III</sup> and Ni<sup>II</sup> ions through a cyanide bridge and between neighboring Ni<sup>II</sup> and Ln<sup>III</sup> (except for Nd<sup>III</sup>) ions through two phenolate bridges. Further magnetic studies show that all of these compounds exhibit single‐chain magnetic behavior. Compound <bold>2</bold> exhibits the highest effective energy barrier (58.2 K) for the reversal of magnetization in 3d/4d/5d–4f heterotrimetallic single‐chain magnets.</p> </abstract>