White Light Emissive DyIII Single-Molecule Magnets Sensitized by Diamagnetic [CoIII(CN)6]3− Linkers

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• 作者：Dr. Szymon Chorazy ; Dr. Michał Rams ; Dr. Koji Nakabayashi ; Prof. Dr. Barbara Sieklucka and Prof. Dr. Shin-ichi Ohkoshi
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：May 23, 2016
• 年：2016
• 卷：22
• 期：22
• 页码：7371-7375
• 全文大小：2760K
• ISSN：1521-3765

文摘

The self-assembly of Dy^III–3-hydroxypyridine (3-OHpy) complexes with hexacyanidocobaltate(III) anions in water produces cyanido-bridged {[Dy^III(3-OHpy)₂(H₂O)₄] [Co^III(CN)₆]}⋅H₂O (1) chains. They reveal a single-molecule magnet (SMM) behavior with a large zero direct current (dc) field energy barrier, ΔE=266(12) cm⁻¹ (≈385 K), originating from the single-ion property of eight-coordinated Dy^III of an elongated dodecahedral geometry, which are embedded with diamagnetic [Co^III(CN)₆]³⁻ ions into zig-zag coordination chains. The SMM character is enhanced by the external dc magnetic field, which results in the ΔE of 320(23) cm⁻¹ (≈460 K) at H_dc=1 kOe, and the opening of a butterfly hysteresis loop below 6 K. Complex 1 exhibits white Dy^III-based emission realized by energy transfer from Co^III and 3-OHpy to Dy^III. Low temperature emission spectra were correlated with SMM property giving the estimation of the zero field ΔE. 1 is a unique example of bifunctional magneto-luminescent material combining white emission and slow magnetic relaxation with a large energy barrier, both controlled by rich structural and electronic interplay between Dy^III, 3-OHpy, and [Co^III(CN)₆]³⁻.