The dinuclear diruthenium complexes ligated by the (µ-aryloxo)bis(µ-carboxylato) system M[Ru2L(µ-O2CR)2] (M = Na, R = Me 1; M = Na, R = Ph 2; M = K, R = Me 3; M = K, R = Ph 4; H5L = 2-hydroxy-5-methyl-m-phenylenedimethylenedinitrilotetraacetic acid) were prepared by the reaction of [RuCl2(Me2SO)4] with L5– and carboxylic acid. The structure of the benzoate-bridged complex 4·0.5MeOH·0.5EtOH·4H2O was elucidated by X-ray crystallography. The Ru· · ·Ru distance was 3.416 Å (average for two crystallographically independent molecules), comparable to those of (µ-alkoxo)bis(µ-carboxylato)diruthenium complexes. The magnetic properties were analysed by a general isotropic exchange Hamiltonian H = –2JS1·S2 (S1 = S2 = ½), yielding meaningfully large antiferromagnetic spin coupling constants (–J = 728 and 649 cm–1 for 1 and 2, respectively). The cyclic voltammogram of 4 in dmf demonstrated two reduction and one oxidation wave corresponding to the four redox states RuII2, RuIIRuIII, RuIII2, RuIIIRuIV. The intervalence coupling constant KC estimated from the potential gap between RuII2/RuIIRuIII and RuIIRuIII/RuIII2 indicated that the introduction of the µ-aryloxo bridge stabilizes the RuIIRuIII mixed-valence species.
由 (µ-aryloxo)bis(µ-carboxylato) 系统 M[Ru2L(µ-O2CR)2] (M = Na, R = Me 1; M = Na, R = Ph 2; M = K, R = Me 3;M=K,R=Ph 4;H5L=2-羟基-5-
甲基-
间苯二胺四乙酸)是通过[RuCl2(Me2SO)4]与 L5-和
羧酸反应制备的。
苯甲酸桥接复合物 4-0.5MeOH-0.5EtOH-4H2O 的结构通过 X 射线晶体学得以阐明。Ru - -Ru 间距为 3.416 Å(两个晶体学上独立分子的平均值),与 (µ-alkoxo)bis(µ-carboxylato)diruthenium 复合物的间距相当。磁性由一般各向同性交换哈密顿 H = -2JS1-
S2(S1 =
S2 = ½)分析,得出了有意义的大反
铁磁自旋耦合常数(1 和 2 的 -J = 728 和 649 cm-1)。4 在 dmf 中的循环伏安图显示了两个还原波和一个
氧化波,分别对应于四种
氧化还原态 RuII2、RuIIRuIII、RuIII2 和 RuIIIRuIV。根据 RuII2/RuIIRuIII 和 RuIIRuIII/RuIII2 之间的电位差估算出的间隔耦合常数 KC 表明,μ-芳香桥的引入稳定了 RuIIRuIII 混合电价物种。