Synthesis of Bent-Form Dinuclear Complexes and Cooperative Interaction of the Two Metal Centers with a Substrate

弯曲双核配合物的合成以及两个金属中心与底物的协同相互作用

基本信息

批准号：
12640540
负责人：
MIYOSHI Katsuhiko
金额：
$ 1.86万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

A bent form of edge-sharing square planar bimetallic complexes is of interest, particularly because axial orbitals of the two metals are in close proximity under the hinged planes to interact cooperatively with a substrate. Such an interaction is expected to play a significant role in binding a substrate to a bimetallic complex.In this study, three types of bisphosphido ligands, MPE, PPE, and PPP (MPE = MePCH_2CH_2PMe^<2->, PPE = PhPCH_2CH_2PPh^<2->, and PPP = PhPCH_2CH_2CH_2PPh^<2->), were used as a bridging unit for the preparation of the edge-sharing bis-squareplanar complexes. X-ray crystal structure analyses were performed for the dipalladium(II) and diplatinum(II) complexes with a general formula (μ-bridge)-[M(DPPE)]_2X_2 (M = Pd, Pt; X = Cl^-, I^-, B(3,5-(CF_3)_2-Ph)_4^-), in which the two metal centers were bridged with the linked-bisphosphido group to form a rare butterfly structure. The dihedral angles between the two "wings" (formed by two metal centers and two bridging P atoms) were around 120°for the ethylene-linked MPE and PPE complexes, whereas the propylene-linked PPP complex adopted a larger value, 131°. It is noteworthy that, in the PPE- and PPP-Pd_2 complexes, a Cl^- or I^- counter anion was situated so as to coordinate to the two Pd(II) centers simultaneously under the hinged planes.Since Rh(I) phosphine complexes are known to be a useful catalyst for numbers of organic reactions, a Rh(I) analog of the above-mentioned butterfly-type dinuclear complex is of interest from the point of view of its catalytic activity. Thus, a dinuclear Rh(I) complex (μ-PPE)-[Rh(COD)]_2 was prepared according to a method similar to that reported for the preparation of (μ-PPh_2)_2-[Rh(COD)]_2. These phosphido-bridged dirhodium(I) complexes were used as a catalyst for polymerization of phenylacetylene to give a cis-transoidal polyphenylacetylene with high regularity.

共享边缘的方形平面双金属复合物的弯曲形式令人感兴趣，特别是因为两种金属的轴向轨道在铰接平面下非常接近，从而与基底相互作用，预计这种相互作用在结合中发挥重要作用。双金属配合物的底物。在这项研究中，三种类型的双磷配体 MPE、PPE 和 PPP (MPE = MePCH_2CH_2PMe^<2->, PPE = PhPCH_2CH_2PPh^<2-> 和 PPP = PhPCH_2CH_2CH_2PPh^<2->) 用作制备共享边缘的双方形平面配合物的桥接单元，并对二钯进行了 X 射线晶体结构分析。 (II) 和二铂(II) 配合物，其通式为 (μ-bridge)-[M(DPPE)]_2X_2 (M = Pd, Pt; X = Cl^-, I^-, B(3,5-(CF_3)_2-Ph)_4^-)，其中两个金属中心通过连接的双磷基桥接对于乙烯连接的 MPE 和 PPE，两个“翅膀”（由两个金属中心和两个桥接 P 原子形成）之间的二面角约为 120°。配合物，而丙烯连接的PPP配合物采用更大的值，131°。值得注意的是，在PPE-和PPP-Pd_2配合物中，Cl^-或I^-反阴离子的位置与配合物配位。两个 Pd(II) 中心同时位于铰接平面下。由于 Rh(I) 膦配合物已知是许多有机反应的有用催化剂，因此上述的 Rh(I) 类似物从催化活性的角度来看，蝴蝶型双核配合物很受关注，因此，根据与报道类似的方法制备了双核Rh(I)配合物(μ-PPE)-[Rh(COD)]_2。用于制备(μ-PPh_2)_2-[Rh(COD)]_2 这些磷桥二铑(I)络合物用作聚合的催化剂。苯乙炔生成具有高规整性的顺反式聚苯乙炔。