Construction of Transition Metal Chalcogenide Clusters and Their Functions

在本研究项目中，我们在多个阶段的研究项目上取得了实质性的进展：1.以Cp^*Re(Se_3)(μ-Se_2)]_8为原料，通过Cp^*Re(Se_3)(μ-Se_2)]_8与Li_2Se_5的2-3当量的反应，合成了一种新型的具有八核钻石冠状[Re(Re-Se_2)]_824元大环核的Re_2Se_3簇合物。Cp^*RECl_4与2当量Li_2Te_5反应生成鸟笼状三核簇合物Cp^*3RE_3Te_8.2。合成了一系列的烷基硫醇配合物、烷基硫醇配合物、二乙叉硫醇配合物。这些硫酸盐配体的独特之处在于它们携带不饱和的C-C键作为取代基，并在各种过渡金属中心显示出有趣的反应活性。例如，我们发现了异常的C-C偶联反应，功能碳中心的环状二聚/三聚，硫代配体上发生的C-S键断裂。硫代型硫在过渡…上配位更多的金属中心相对较强，而硫醚型硫形成较弱的M-S键，往往表现出较容易的解离平衡。我们利用混合配体rSCH_2CH_2S(-)(R=Et(Ett)，R=1ipr(^1ptet)，R=Ph(Ptet))组装了铁(II)和镍(II)金属原子。例如，1：2NiCl2/Li(Ett)反应体系生成线性聚合物[Ni(Ett)2]n，而类似的1：2NiCl2/Li(Ptet)反应生成环状六聚体[Ni6(Ptet)&lt；12&gt；]。这些一维的镍和铁聚合物的一个有趣的特征是，它们可以通过硫醚型硫原子的配位作用溶解在甲苯中，并且聚合物结构在重结晶时重新生成。合成了一系列硫桥钨-Ru双核配合物Cp^*W(μ-S)_3RuX(PPh_3)_2、Cp^*W(O)(μ-S)_2RuX(PPh_3)_2和Cp^*W(NPh)(μ-S)_2RuX(PPh_3)_2。发现Cp^*W(O)(μ-S)_2RuX(PPh_3)_2和Cp^*W(NPh)(μ-S)_2RuX(PPh_3)_2在常压下分别与NaBArF_4反应生成[Cp^*W(OH)(μ-S)_2RuH(PPh_3)_2](BarF_4)和[Cp^*W(NHPh)(μ-S)_2RuH(PPh_3)_2](BarF_4)。研究了异解H_2活化和逆析氢反应机理。较少

During this research project, we have made substantial progress in many phases of research items, viz,1. We have synthesized a novel rhenium selenido cluster, of [Cp^*Re(Se_3)(μ-Se_2)]_8, having a octa-nuclear diamond-crown shape of [Re(μ-Se_2)]_8 24-membered macrocyclic core, from the reaction of Cp^*ReCl_4 with 2-3 equiv of Li_2Se_5. On the other hand, the analogous reaction between Cp^*ReCl_4 and 2 equiv of Li_2Te_5 gave rise to a trinuclear cluster of a birdcage shape, Cp^*3Re_3Te_8.2. A series of alkynethiolato complexes, alkyneselenolato complexes, diynethiolato complexes have been synthesized. These thiolate ligands are unique in that they carry unsaturated C-C bonds as substituents, and have shown interesting reactivity at various transition metal centers. For instance, we found unusual C-C coupling reactions, cyclic dimerizatino/trimerization of the functional carbon sites, C-S bond cleavage occurring at the thiolate ligands.3. Thiolate-type sulfur is coordinated at transition … More metal centers relatively strongly, while thioether-type sulfur forms weak M-S bonds, often exhibiting facile dissociation equilibration. We have utilized the mixed ligands RSCH_2CH_2S(-) (R=Et (etet), R=^iPr (^1ptet), R=Ph (ptet)) for assemblage of iron(II) and Ni(II) metal atoms. For instance, the 1:2 NiCl_2/Li(etet) reaction system gave rise to a linear polymer [Ni(etet)_2]_n, while the analogous 1:2 NiCl_2/Li(ptet) reaction resulted in formation of a cyclic hexamer [Ni_6(ptet)_<12>]. An interesting feature of these 1-dimensional polymers of Ni and Fe is that they can be dissolved in toluene by virtue of coordination of thioether-type sulfur atoms, and that the polymer structures are regenerated upon recrystallization.4. A series of sulfido-bridged tungsten-ruthenium dinuclear complexes Cp^*W(μ-S)_3RuX(PPh_3)_2, Cp^*W(O) (μ-S)_2RuX(PPh_3)_2, and Cp^*W(NPh) (μ-S)_2RuX(PPh_3)_2 have been synthesized. The heterolytic cleavage of H_2 was found to proceed at room temperature upon treating Cp^*W(O) (μ-S)_2RuX(PPh_3)_2 and Cp^*W(NPh)(μ-S)_2RuX(PPh_3)_2 with NaBArF_4 under atmospheric pressure of H_2, which gave rise to [Cp^*W(OH)(μ-S)_2RuH(PPh_3)_2](BarF_4) and [Cp^*W(NHPh)(μ-S)_2RuH(PPh_3)_2](BarF_4), respectively. The mechanism of the heterolytic H_2 activation and the reverse H_2 evolution reactions have been investigated. Less