Synthesis, Crystal Structure, and Magnetic Properties of the Coordination Polymer [Fe(NCS)2(1,2-bis(4-pyridyl)-ethylene)]n Showing a Two Step Metamagnetic Transition
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- 作者：Susanne W枚hlert ; Mario Wriedt ; Tomasz Fic ; Zbigniew Tomkowicz ; Wolfgang Haase ; Christian N盲ther
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：January 18, 2013
- 年：2013
- 卷：52
- 期：2
- 页码：1061-1068
- 全文大小：443K
- 年卷期：v.52,no.2(January 18, 2013)
- ISSN：1520-510X
文摘
Reaction of iron(II) thiocyanate with an excess of trans-1,2-bis(4-pyridyl)-ethylene (bpe) in acetonitrile at room temperature leads to the formation of [Fe(NCS)2(bpe)2路(bpe)] (1), which is isotypic to its Co(II) analogue. Using slightly different reaction conditions the literature known compound [Fe(NCS)2(bpe)2(H2O)2] (2) was obtained as a phase pure material. Simultaneous differential thermoanalysis and thermogravimetry prove that the hydrate 2 transforms into the anhydrate [Fe(NCS)2(bpe)2] (3), that decomposes on further heating into the new ligand-deficient 1:1 compound of composition [Fe(NCS)2(bpe)]n (4), which can also be obtained directly by thermal decomposition of 1. Further investigations reveal that 4 can also be prepared under solvothermal conditions, and single crystal structure analysis shows that the iron(II) cations are linked via 渭-1,3 bridging thiocyanato anions into chains, that are further connected into layers by the bpe ligands. Magnetic measurements, performed on powder samples, prove that 1 and 2 show only Curie鈥揥eiss behavior, whereas in 4 antiferromagnetic ordering with a N茅el temperature of 5.0 K is observed. At T < 4.0 K a two-step metamagnetic transition occurs at applied magnetic fields of 1300 and 1775 Oe. The magnetic properties are discussed and compared with those of related compounds.