Synthesis, crystal structure, electrochemical and magnetic properties of (NBu₄)[ReCl₅(L)] with L = pyrimidine and pyridazine

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• 作者：Livia Arizaga ; Ricardo Gonzá ; lez ; Raú ; l Chiozzone ; Carlos Kremer ; Marí ; a Fern ; a Cerdá ; Donatella Armentano ; Giovanni De Munno ; Francesc Lloret ; Juan Faus
• 关键词：Rhenium(IV) complexes ; Pyrimidine and piridazine ; X-ray structure ; Cyclic voltammetry ; Magnetic properties
• 刊名：Polyhedron
• 出版年：2008
• 出版时间：6 February 2008
• 年：2008
• 卷：27
• 期：2
• 页码：552-558
• 全文大小：332 K

文摘

Two novel rhenium(IV) compounds, namely (NBu₄)[ReCl₅(pym)] (1) and (NBu₄)[ReCl₅(pyd)] (2) (pym = pyrimidine, pyd = pyridazine and NBu₄ = n-tetrabutylammonium cation), have been obtained by reaction of [ReCl₆]²⁻ and the diazine in dmf, and their crystal structures determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of [ReCl₅(pym)]⁻ or [ReCl₅(pyd)]⁻ anions and md5=30ae0dade48de2a5e70b8a06fbd69f92""> cations held together by electrostatic forces and van der Waals interactions. Stacking interactions are present only in 1. The coordination sphere of the Re^IV ion is defined by five chloride anions and one nitrogen atom of a monodentate diazine, resulting in a distorted octahedral environment. Voltammetric profiles in CH₃CN show a one-electron reduction step at ca. −0.5 V vs. NHE for both complexes. Magnetic measurements reveal weak antiferromagnetic interactions among the metal centers in the crystal lattices of 1 and 2, superimposed to the well-known zero-field splitting of Re(IV) compounds.