Carrasco Rosa, Cano Joan, Mallah Talal, Jones Leigh F, Collison David, Brechin Euan K
Laboratoire de Chimie Bioorganique et Bioinorganique, UMR 8613, Institut de Chimie Moléculaire d'Orsay, Université de Paris-Sud, 91405 Orsay, France.
Inorg Chem. 2004 Aug 23;43(17):5410-5. doi: 10.1021/ic049547v.
The reaction of the trimetallic species [Fe(3)O(PhCOO)(6)(H(2)O)(3)]NO(3) with 1,1,1-tris(hydroxymethyl)ethane (H(3)thme) affords either the octametallic species [Fe(8)(PhCOO)(12)(thme)(4)] 1 or the hexadecametallic species Fe(16)(EtO)(4)(PhCOO)(16)(Hthme)(12)(4) 2, depending on the nature of the solvent used for crystallization. The structure of 1 can be described as a nonplanar wheel of eight Fe(III) ions bridged by a combination of PhCOO(-) and thme(3)(-) ligands, and 2 as a nonplanar wheel of sixteen Fe(III) ions bridged by PhCOO(-), Hthme(2)(-), and EtO(-) ligands. Both compounds can be broken down into simple units of two metal ions and the bridging ligands that connect them. The best fits of the chi vs T curves in the 300-10 K temperature range were obtained with the parameters g = 2.0, J(1) = -24.0 cm(-1), and J(2) = -8.59 cm(-1) for [Fe(8)] and g = 2.0, J(1) = -25.0 cm(-1), J(2) = -11.73 cm(-1), and J(3) = -69.3 cm(-1) for [Fe(16)]. Density functional theory (DFT) calculations show that the antiferromagnetic interactions between the metals in the dinuclear units decrease when two types of bridging ligands are present, as expected for an orbital counter-complementarity effect.
三金属物种[Fe₃O(PhCOO)₆(H₂O)₃]NO₃与1,1,1 - 三(羟甲基)乙烷(H₃thme)反应，根据用于结晶的溶剂性质，可得到八金属物种[Fe₈(PhCOO)₁₂(thme)₄] 1或十六金属物种Fe₁₆(EtO)₄(PhCOO)₁₆(Hthme)₁₂₄ 2。1的结构可描述为由PhCOO⁻和thme³⁻配体组合桥连的八个Fe(III)离子构成的非平面轮状结构，2的结构为PhCOO⁻、Hthme²⁻和EtO⁻配体桥连的十六个Fe(III)离子构成的非平面轮状结构。两种化合物都可分解为两个金属离子以及连接它们的桥连配体的简单单元。对于[Fe₈]，在300 - 10 K温度范围内，χ对T曲线的最佳拟合参数为g = 2.0、J₁ = -24.0 cm⁻¹和J₂ = -8.59 cm⁻¹；对于[Fe₁₆]，最佳拟合参数为g = 2.0、J₁ = -25.0 cm⁻¹、J₂ = -11.73 cm⁻¹和J₃ = -69.3 cm⁻¹。密度泛函理论(DFT)计算表明，如轨道反互补效应所预期的那样，当存在两种类型的桥连配体时，双核单元中金属之间的反铁磁相互作用会减弱。
