All-cis-1,2,3,4,5,6-cyclohexanehexacarboxylate two-dimensional gadolinium(III) complexes: Synthesis, X-ray crystal structure and magnetic properties

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• 作者：Laura Cañ ; adillas-Delgado ; Oscar Fabelo ; Jorge Pasá ; n ; Miguel Julve ; Francesc Lloret ; Catalina Ruiz-Pé ; rez
• 关键词：Gadolinium(III) coordination complexes ; 1 ; 2 ; 3 ; 4 ; 5 ; 6-Cyclohexanehexacarboxylate complexes ; Metal– ; organic frameworks ; Single crystal X-ray diffraction ; Magnetic properties
• 刊名：Polyhedron
• 出版年：2010
• 出版时间：13 January 2010
• 年：2010
• 卷：29
• 期：1
• 页码：188-195
• 全文大小：1339 K

文摘

The first gadolinium(III) complexes with the trideprotonated form of the 1,2,3,4,5,6-cyclohexanehexacarboxylic acid (H₃clhex³⁻) of formulae [Gd(H₃clhex)(H₂O)₄]_n·3nH₂O (1) and [Gd(H₃clhex)(H₂O)₄]_n·6nH₂O (2) have been prepared through the gel technique and their structures determined by single crystal X-ray diffraction. The structure of 1 is made up of 6³ honey-comb layers which are generated by [Gd(H₂O)₄]³⁺ cations and H₃clhex³⁻ anions acting as three-fold nodes and three-fold connectors, respectively. The structure of 2 consists of a [4⁴,6²] two-dimensional network extended in the ac plane where the H₃clhex⁻³ groups act as four-fold connectors and the [Gd(H₂O)₄]³⁺ units as four-fold nodes. Compound 1 crystallises in a non-centrosymmetric space group P2₁. Its absolute structure could be determined reliably, indicating the spontaneous resolution of a homochiral crystal and the freezing of one of the conformations of the all-cis H₃clhex⁻³ ligand. Compound 2 crystallises in the P2₁/n space group, the presence of an inversion centre making both conformations to occur. 1 and 2 are different solvates of the same system, the latter one synthesised under a higher pH value of the gel than the former. The investigation of the magnetic properties of 1 and 2 in the temperature range 1.9–300 K reveals a Curie law behaviour for the two compounds.