Synthesis and New Reactivity of Nano-scale Conjugated Transition Metal Molecules

一维共价金属弦的构建由于其基本的成键性质以及作为广泛的电子和光电子材料的应用前景而引起了人们的广泛关注。这些化合物的两种主要合成方法是：(a)使用多齿配体，如寡聚α-吡啶酰胺配体，或(b)部分氧化d^8方平面配合物形成金属-金属键（如铂蓝）。我们的工作主要集中在利用一种三叉戟配体6-二苯基膦-2-吡啶醇（pypyhos）对过渡金属进行配位，其中三种不同的元素P，N和O在刚性吡啶酮框架中线性排列，并且可以作为两种以上过渡金属线性排列的配位位。利用四界二钼（II）配合物，以Mo_2（磷）_4(1)为核心，制备了含有VI族和X族金属的线性异金属团簇，并以Mo_2Pd_2Cl_2（磷）_4(2)等部分金属串为核心，制备了具有Rh-Mo-Mo-Rh阵列和独特氧化反应的线性排列的四核配合物。我们发现，在Mo_2簇1的两个轴向位置上的铑金属通过Mo_2核进行电子通信，因此，Rh(I)/Rh（II）氧化反应诱导了金属-金属键的形成。通过两个等量的（Cp_2Fe）PF_6氧化4a的每个Rh(I)原子，生成[Mo_2Rh_2(Cl)_2(^tBuNC)_4(pyphos)_4](PF_6)_2(5)，形成两个Mo-Rh（II）单键，并使Mo-Mo部分的键序降低，从而形成4个过渡金属通过3个金属-金属键线性结合的金属-纳米线。Pd_2Cl_2(CNC_6H_3Me_2-2 -2,6)_4(6)和Mo_2(O_2CCF_3)_4(7)在二氯甲烷中处理后，形成了一个无限之字链{[Pd_2Cl_2(CNC_6H_3Me_2-2 -2,6)_4][Mo_2(O_2CCF_3)_4]}_n(8)，其中两个金属-金属键双核单元Pd-Pd和Mo-Mo由氯原子桥接。8的Mo-Mo距离（2.1312（3)Å）比7的Mo-Mo距离（2.090(4)）Å）明显拉长，处于四重Mo-Mo键配合物的距离范围内。这种延伸可能归因于Pd-Pd单元的氯原子向Mo-Mo部分的轴向捐赠。少

The construction of one-dimensional, covalently bonded metal strings has attracted much interest in view of fundamental bonding nature as well as promising applications as extensive electronic and optoelectronic materials. Two major synthetic approaches to these compounds have been conducted by (a)using polydentate ligands such as oligo-α-pyridylamido ligands or by (b)partial oxidation of d^8 square-planar complexes to form metal-metal bonds (e.g. platinum blue). Our effort has been focused on aligning transition metals by using a tridentate ligand 6-diphenylphosphino-2-pyridonate (pyphos), in which three different elements, P,N, and O, were linearly laid out by the rigid pyridone framework and could act as coordination sites for arrangement of more than two kinds of transition metals in linear manner. And we have demonstrated linear hetelometallic clusters containing both group VI and group X metals by use of the quadruply-bounded dimolybdenum(II) complex, Mo_2(pyphos)_4 (1)as a core … More part of metal strings such as Mo_2Pd_2Cl_2(pyphos)_4 (2)We have prepared linearly aligned tetranuclear complexes bearing the Rh-Mo-Mo-Rh array and their unique oxidative reaction. We found that rhodium metals at both axial positions of the Mo_2 cluster 1 electronically communicated through the Mo_2 core and, as a result, oxidative reaction Rh(I)/Rh(II) induced the formation of metal-metal bonds.The formation of a metal-nanowire, of which four transition metals are linearly bounded through three metal-metal bonds, was accomplished by oxidation of each Rh(I) atom of 4a by two equiv of (Cp_2Fe)PF_6 to afford [Mo_2Rh_2(Cl)_2(^tBuNC)_4(pyphos)_4](PF_6)_2 (5)accompanied by the formation of two Mo-Rh(II) single bonds and the reduction of bond order of the Mo-Mo moiety.Treatment of Pd_2Cl_2(CNC_6H_3Me_2-2,6)_4 (6)and Mo_2(O_2CCF_3)_4 (7)in dichloromethane afforded an infinite zigzag chain {[Pd_2Cl_2(CNC_6H_3Me_2-2,6)_4][Mo_2(O_2CCF_3)_4]}_n (8), where two metal-metal bonded dinuclear Pd-Pd and Mo-Mo units were bridged by chloro atoms. The Mo-Mo distance (2.1312(3) Å of 8 is significantly elongated compared to that of 7 (2.090(4)) Å) and lies in the range of that of the quadruple Mo-Mo bonded complexes. Such the elongation might be attributed to the axial donation of the chloro atoms of the Pd-Pd unit to the Mo-Mo moiety. Less