New pentachromoium metal string complexes [Cr5(μ5-L)4X2] (X = Cl−, L = dppzda2− (1), dpzpda2− (2); X = NCS−, L = dppzda2− (3), dpzpda2− (4)) were designed and synthesized through pyrazine-modulation of tripyridyldiamine ligand. X-Ray crystallographic studies revealed a linear metal chain structure consisting of two quadruple Cr–Cr bonds and a separated high spin Cr(II) at an end in crystallized form. A quintet ground state was observed for all pentachromium(II) molecules by magnetic study with g values of 2.04–2.18. While the electronic structure remained unchanged after the modification of ligands, electrochemistry showed a significant change in the molecular orbital energy levels of metal string molecules. Observation of the first oxidation peak of 1 at +0.57 V and of 2 at +0.73 V revealed that these complexes are quite resistant to oxidation. Single molecular conductance measurements showed that the complex exhibited good electronic conductance.
新型五
铬金属串配合物 [Cr5(μ5-L)4X2] (X = Cl−, L = dppzda2− (1), dpzpda2− (2); X =
NCS−, L = dppzda2− (3), dpzpda2− ( 4))是通过三
吡啶二胺
配体的
吡嗪调节来设计和合成的。 X 射线晶体学研究揭示了线性
金属链结构,由两个四重 Cr-Cr 键和末端结晶形式的分离的高自旋 Cr(II) 组成。通过磁性研究,g 值为 2.04–2.18,观察到所有五
铬 (II) 分子的五重基态。虽然
配体修饰后电子结构保持不变,但电
化学显示
金属串分子的分子轨道能级发生了显着变化。对 +0.57 V 处的 1 和 +0.73 V 处的 2 的第一个氧化峰的观察表明,这些配合物具有相当的抗氧化性。单分子电导测量表明该配合物表现出良好的电子电导。