Metal鈥揗etal Interactions in Trinuclear Copper(II) Complexes [Cu3(RCOO)4(H2TEA)2] and Binuclear [Cu2(RCOO)2(H2TEA)2]. Syntheses and Combined Structural, Magnetic, High-Field Electron Paramagnetic Reson

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• 作者：Andrew Ozarowski ; Carmen J. Calzado ; Raj Pal Sharma ; Santosh Kumar ; Julia Jezierska ; Celestino Angeli ; Federico Spizzo ; Valeria Ferretti
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：December 21, 2015
• 年：2015
• 卷：54
• 期：24
• 页码：11916-11934
• 全文大小：1209K
• ISSN：1520-510X

文摘

The trinuclear [Cu₃(RCOO)₄(H₂TEA)₂] copper(II) complexes, where RCOO^{鈥?/sup> = 2-furoate (1), 2-methoxybenzoate (2), and 3-methoxybenzoate (3, 4), as well as dimeric species [Cu₂(H₂TEA)₂(RCOO)₂]路2H₂O, have been prepared by adding triethanolamine (H₃TEA) at ambient conditions to hydrated Cu(RCOO)₂ salts. The newly synthesized complexes have been characterized by elemental analyses, spectroscopic techniques (IR and UV鈥搗isible), magnetic susceptibility, single crystal X-ray structure determination and theoretical calculations, using a Difference Dedicated Configuration Interaction approach for the evaluation of magnetic coupling constants. In 1 and 2, the central copper atom lies on an inversion center, while in the polymorphs 3 and 4, the three metal centers are crystallographically independent. The zero-field splitting parameters of the trimeric compounds, D and E, were derived from high-field, high-frequency electron paramagnetic resonance spectra at temperatures ranging from 3 to 290 K and were used for the interpretation of the magnetic data. It was found that the dominant interaction between the terminal and central Cu sites J₁₂ is ferromagnetic in nature in all complexes, even though differences have been found between the symmetrical or quasi-symmetrical complexes 1鈥?b>3 and non-symmetrical complex 4, while the interaction between the terminal centers, J₂₃, is negligible.}