七核与十三核钴簇合物：合成、结构、磁性与DFT计算.docVIP

  Disk-like Hepta- and Tridecanuclear Cobalt Clusters. Synthesis, Structure, Magnetic Properties and DFT 5 10 15 20 25 30 35 40 calculations# Ji-Dong Leng1, Su-Kun Xing1, Radovan Herchel2, Ming-Liang Tong1** (1. School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275; 2. Department of Inorganic Chemistry, Palacky University) Abstract: The synthesis, structure and magnetic properties are reported of two disk-like mixed-valence cobalt clusters [CoIIICoII6(thmp)2(acac)6(ada)3] (1) and [CoIII2CoII11(thmp)4(Me3CCOO)4(acac)6(OH)4(H2O)4](Me3CCOO)2.H2O (2). Heptanuclear complex 1 was prepared by solvothermal reaction of cobalt(II) acetylacetonate (Co(acac) 2), 1,1,1-tris(hydroxymethyl)-propane (H3thmp), and adamantane-1-carboxylic acid (Hada), whereas by substituting Hada with (CH3)3CCO2H, tridecanuclear complex 2 was obtained with an unexpected [CoIII2CoII11] core. The core structures of 1 and 2 are related to each other: that of 1 arrange as a centered hexagon of a central CoIII ion surrounded by a [CoII6] hexagon, while that of 2 can be described as a larger oligomer based on two vertex sharing [CoIIICoII6]. Variable-temperature direct current (dc) magnetic susceptibility measurements demonstrated overall ferromagnetic coupling between the CoII ions within both two clusters. The magnetic exchange (J) and magnetic anisotropy (D) was quantified with appropriate spin Hamiltonians models and also supported by DFT calculations. The presence of frequency-dependent out-of-phase ac susceptibility signals at temperatures below 3 K suggested that 2 might be a single-molecule magnet. Key words: cobalt cluster; structure; magnetic properties; DFT studies 0 Introduction A great number of polynuclear complexes have been synthesized and investigated in the past decade, because of their interesting physical or catalytic properties, and especially, their potential to function as single-mol