Copper(II)/di-2-pyridyl ketone chemistry: A triangular cluster displaying antisymmetric exchange versus an 1D coordination polymer

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• 作者：Constantinos G. Efthymiou ; Catherine P. Raptopoulou ; Vassilis Psycharis ; Anastasios J. Tasiopoulos ; Albert Escuer ; Spyros P. Perlepes ; Constantina Papatriantafyllopoulou
• 关键词：Antisymmetric exchange interaction ; Copper(II) clusters ; Copper(II) coordination polymers ; Crystal structures ; Di-2-pyridyl ketone ; Magnetic properties
• 刊名：Polyhedron
• 出版年：2013
• 出版时间：12 November, 2013
• 年：2013
• 卷：64
• 期：Complete
• 页码：30-37
• 全文大小：958 K

文摘

The systematic study of the reaction system copper(II) perchlorate/di-2-pyridyl ketone, (py)₂CO, provided access to the new trinuclear compound [Cu₃{(py)₂C(OMe)(O)}₃(H₂O)](ClO₄)₃¡¤MeOH¡¤0.6H₂O (1¡¤MeOH¡¤0.6H₂O), and the 1D coordination polymer [Cu₂{(py)₂C(OEt)(O)}(HCO₂)₂(ClO₄)(MeCN)]_n (2) bearing the anionic hemiketal forms of (py)₂CO. Both compounds were prepared from reactions of Cu(ClO₄)₂¡¤6H₂O with the ligand, in the presence of NEt₃ in MeOH (1) or MeCN/TEOF (2), where TEOF is triethylorthoformate. Compound 1 possesses a triangular metal topology representing an example of a non-oxido/hydroxido/methoxido-centered Cu₃ species. Compound 2 is based on dinuclear units linked through HCO₂^? groups forming an 1D chain. EPR spectra and variable temperature dc magnetic susceptibility studies on powdered polycrystalline samples of 1 revealed the presence of strong antiferromagnetic interactions between the metal centers leading to an S = 1/2 ground state. The magnetic susceptibility data were fit using a model including antisymmetric exchange interactions and the antisymmetric exchange vector parameter G_Z value has been determined.