Halide Influence on Molecular and Supramolecular Arrangements of Iron Complexes with a 3,5-Bis(2-Pyridyl)-1,2,4,6-Thiatriazine Ligand

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• 作者：Katie L. M. Harriman ; Irina A. Kühne ; Alicea A. Leitch ; Ilia Korobkov ; Rodolphe Clérac ; Muralee Murugesu ; Jaclyn L. Brusso
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：June 6, 2016
• 年：2016
• 卷：55
• 期：11
• 页码：5375-5383
• 全文大小：688K
• 年卷期：0
• ISSN：1520-510X

文摘

A series of iron centered complexes, namely, [Fe(Py₂TTA)Cl₂] (1), [Fe(Py₂TTA)Br₂] (2), and [Fe(μ-F)(Py₂TTAO)F]_∞ (3), were isolated via complexation of 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazine (Py₂TTAH) with various ferric halides (e.g., FeF₃, FeCl₃, and FeBr₃). Comparison of the optical and electrochemical spectroscopy, structural analysis, and magnetic studies reveal numerous similarities between the chlorido (1) and bromido (2) derivatives, which crystallize as discrete five-coordinate iron centered complexes with coordination geometries that are intermediate between trigonal bipyramidal and square base pyramid. Conversely, the fluorido derivative (3) results in a completely different structure due to oxidation of the ligand and the formation of a one-dimensional coordination polymer held together through a bridging fluoride ion. Consequently, the spectroscopic and magnetic behavior of 3 differs significantly compared with 1 and 2. Complexes 1 and 2 exhibit paramagnetic properties typical for a mononuclear S = 5/2 system with weak intermolecular antiferromagnetic interactions at low temperatures, whereas complex 3 demonstrates significant exchange couplings within the chain and weak antiferromagnetic interchain interactions, which stabilize a canted antiferromagnetic state below 4.2 K.