Interpenetrated (8,3)-c and (10,3)-b Metal鈥揙rganic Frameworks Based on {FeIII3} and {FeIII2CoII} Pivalate Spin Clusters

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• 作者：Olga Botezat ; Jan van Leusen ; Victor Ch. Kravtsov ; Irina G. Filippova ; J眉rg Hauser ; Manfred Speldrich ; Rapha毛l P. Hermann ; Karl W. Kr盲mer ; Shi-Xia Liu ; Silvio Decurtins ; Paul K枚gerler ; Svetlana G. Baca
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：September 3, 2014
• 年：2014
• 卷：14
• 期：9
• 页码：4721-4728
• 全文大小：372K
• ISSN：1528-7505

文摘

Two new magnetic cluster-based 3D coordination polymers consisting of 渭₃-oxo-centered cationic homometallic [Fe^III₃O(O₂CCMe₃)₆]⁺ or neutral heterometallic [Fe^III₂Co^IIO(O₂CCMe₃)₆] coordination clusters bridged by different N,N鈥?donor ligands into three-dimensional networks of {[Fe₃O(O₂CCMe₃)₆(4,4鈥?bpy)_1.5](OH)路0.75(CH₂Cl₂)路x(H₂O)}_n (1, x 鈮?8) and {[Fe₂CoO(O₂CCMe₃)₆(bpe)_0.5(pyz)]}_n (2) (where 4,4鈥?bpy = 4,4鈥?bipyridine; bpe = 1,2鈥?bis(4-pyridyl)ethylene; pyz = pyrazine) have been prepared under solvothermal conditions. Single-crystal X-ray diffraction studies reveal the existence of a 6-fold interpenetrated network with rare (8,3)-c (etc) topology for 1 and a 3-fold interpenetrated network with (10,3)-b (ths) topology for 2. The interpenetration effectively results in very low BET surface areas, and the compounds have to be regarded as nonporous. Magnetic studies of 1 and 2 point to both ferro- and antiferromagnetic intra- and intercluster exchange interactions between the isotropic Fe^III and the strongly anisotropic Co^II spin centers. ⁵⁷Fe M枚ssbauer spectroscopy confirms the uniform ferric (+III) valence state in both 1 and 2, and low-temperature data for 1 point toward distinct hyperfine fields for the Fe sites.