Partially Oxidized Transition-Metal Clusters with High Electrical Conductance

该项目旨在利用过渡金属簇合物中MM键的易极化和离域化的电子特性来开发部分氧化材料。从实验和理论两方面考察了金属镝配合物的单电子氧化引起的几何构型位移，表明这些位移可以用来指认参与电离的分子轨道。根据~1Hδ-π的顺磁位移，估计了桨轮型分子中桥联芳香族配体与MM键之间的分子内核磁共振电子相互作用，导致MM键上约10%的奇电子密度离域到每个桥联配体的π体系上。根据这些阳离子自由基分子的磁性，研究了它们在晶体中π堆叠排列中的分子间电子相互作用。只有高自旋密度碳原子之间的短分子间接触才会产生可检测到的磁相互作用。这些自由基盐与相应的中性络合物机械混合后，其电导增加了10~4。ESR.X-射线粉末衍射数据表明，混合诱导了电子从中性络合物到阳离子自由基盐的掺杂，混合物中的所有奇电子不仅跳过了结晶粒子中的每个分子，也跳过了混合物中的粒子，没有产生新的相。合成了具有新型笼型核结构的四膦配合物，并对其反应活性进行了考察，为合成混配的镝配合物开辟了一条新的途径。一些烯烃化合物的催化氰化反应也得到了发展。

This project aims to develop partially oxidized material by utilizing easily polarizable and delocalizable electronic characteristics of MM bonds in transition-metal cluster complexes. The shifts of the geometries induced by one-electron oxidation of dirhodium complexes were examined experimentally and theoretically to show that the shifts can be utilized to assign the molecular orbital involved in the ionization. The intramolecular δ-π electronic interaction between MM bond and bridging aromatic ligands in paddlewheel-type dirhodium cationic radical salts has been estimated to induce around 10% of the odd-electron density on the MM bond is delocalized onto the π system of each of the bridging ligands based on the ^1H NMR paramagnetic shifts. Intermolecular electronic interaction in π stack arrangement of such type of cationic radical molecules in crystals of their salts was evaluated based on their magnetism. Only short intermolecular contacts between high-spin-density carbon atoms induce detectable magnetic interaction. Mechanic mixture of such radical salts with the corresponding neutral complexes induced 10^4 increase of their electrical conductance. The mixing was shown to induce doping of electron from the neutral complex to the cationic radical salt, and all the odd-electrons in the mixture hop not only over each of molecules in a crystalline particle but also over particles in the mixture as shown by ESR.X-ray powder diffraction data showed that no new phase was developed by the mixing. Tetrarhodium complexes with new cage-type core structure have been synthesized and their reactivity has been examined to develop a new synthetic method for mixed-ligand dirhodium complexes. Some catalytic cyanation reactions of olefinic compounds have been also developed.