Copper(II), Nickel(II), and Cobalt(II)/(III) Self-Assembled Polynuclear Complexes of Bis[(pyridin-2-yl)-1,2,4-triazol-3-yl]]methane

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• 作者：Alexey N. Gusev ; Victor F. Shul'gin ; Irina O. Ryush ; Miki Hasegawa ; Mikhail A. Kiskin ; Nikolay N. Efimov ; Konstantin A. Lyssenko ; Igor L. Eremenko and Wolfgang Linert
• 刊名：European Journal of Inorganic Chemistry
• 出版年：2017
• 出版时间：January 18, 2017
• 年：2017
• 卷：2017
• 期：3
• 页码：704-712
• 全文大小：2642K
• ISSN：1099-0682c

文摘

The reactions of bis[(pyridin-2-yl)-1,2,4-triazol-3-yl]methane (H₂L) with copper(II), nickel(II), and cobalt(II) salts afford a series of unusual structures; among them are the homoleptic binuclear complexes [Ni₂(H₂L)₂(H₂O)₄](NO₃)₄·6H₂O (1) and [Ni₂(H₂L)₂Cl₂]Cl₂·4H₂O·2C₄H₈O₂ (2), the octanuclear complex [Ni₈(H₂L)₁₂](NO₃)₁₆·21H₂O (3), and the tetranuclear complexes [Cu₄(HL)₄](ClO₄)₄·C₂H₅OH·3H₂O (4), [Co₄(HL)₂(H₂L)₂(H₂O)₄](NO₃)₈·C₂H₅OH·6H₂O (5), and [Co₄(HL)₂(H₂L)₂(H₂O)₄]·(ClO₄)₈·8H₂O (6). All these compounds have been characterized by different techniques, such as elemental analysis, electrospray mass spectrometry (ES-MS), UV/Vis spectroscopy, X-ray structural analyses, and magnetic measurements. It was found that the nature of the cation and the metal/ligand ratio have a substantial impact on the coordination geometries of the unique complexes. The magnetic properties of compounds 1 and 2 show the presence of intramolecular ferromagnetic exchange interactions (J = +2.3 and +15.2 cm^–1) combined with intermolecular antiferromagnetic coupling. Complexes 3, 5, and 6 show weak intramolecular antiferromagnetic interactions, while complex 4 shows quite strong antiferromagnetic behavior (J = –53.7 cm^–1).