Understanding Spin Structure in Metallacrown Single-Molecule Magnets using Magnetic Compton Scattering

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• 作者：Aniruddha Deb ; Thaddeus T. Boron ; III ; Masayoshi Itou ; Yoshiharu Sakurai ; Talal Mallah ; Vincent L. Pecoraro ; James E. Penner-Hahn
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：April 2, 2014
• 年：2014
• 卷：136
• 期：13
• 页码：4889-4892
• 全文大小：257K
• 年卷期：v.136,no.13(April 2, 2014)
• ISSN：1520-5126

文摘

The 3d鈥?f mixed metallacrowns frequently show single-molecule magnetic behavior. We have used magnetic Compton scattering to characterize the spin structure and orbital interactions in three isostructural metallacrowns: Gd₂Mn₄, Dy₂Mn₄, and Y₂Mn₄. These data allow the direct determination of the spin only contribution to the overall magnetic moment. We find that the lanthanide 4f spin in Gd₂Mn₄ and Dy₂Mn₄ is aligned parallel to the Mn 3d spin. For Y₂Mn₄ (manganese-only spin) we find evidence for spin delocalization into the O 2p orbitals. Comparing the magnetic Compton scattering data with SQUID studies that measure the total magnetic moment suggests that Gd₂Mn₄ and Y₂Mn₄ have only a small orbital contribution to the moment. In contrast, the total magnetic moment for Dy₂Mn₄ MCs is much larger than the spin-only moment, demonstrating a significant orbital contribution to the overall magnetic moment. Overall, these data provide direct insight into the correlation of molecular design with molecular magnetic properties.