Heterometallic Polyhydride Compounds: Synthesis and Reactivity (Chemistry)

氢化作用，即氢在其他原子或分子上的加成作用，是一个极其重要的化学过程。例如，将玉米油转化为人造黄油和利用煤进行化学合成都涉及到氢化，毫无疑问，未来利用太阳能的实际方案也将涉及到氢化。本课题的研究重点是合成金属-氢化合物，金属-氢化合物可以加氢其他化合物或催化加氢反应。该项目涉及合成和研究化合物的反应性，优化氢转移到可还原底物，如CO，二氧化碳和烯烃。这种化合物含有两种不同的金属，要么是两种过渡金属，要么是一种过渡金属和一种高正电性金属（Zn， Y, Sm ....），以及许多氢化物配体。这些异金属氢化物将采用三种不同的合成方法。在初步工作中，观察到一种杂双金属多氢化物对二氧化碳的还原作用。由于从动力学和热力学的角度来看，不成对的电子密度应该促进这种氢化反应，因此也将合成具有不成对电子的单体金属多氢化物。单体和杂双金属多氢化物将根据它们的动力学过程（例如通过EPR光谱）和它们的化学反应性进行表征。

Hydrogenation, the addition of hydrogen to other atoms or molecules, is an extremely important chemical process. For example, hydrogenation is involved in the conversion of corn oil to margarine and in the utilization of coal for chemical synthesis, and will undoubtedly be involved also in future practical schemes for the utilization of solar energy. The focus of this research project is the synthesis of metal-hydrogen compounds of metals which can hydrogenate other compounds or catalyze hydrogenation reactions. This project involves the synthesis and investigation of the reactivity of compounds optimized for hydrogen transfer to reducible substrates such as CO, carbon dioxide and olefins. Such compounds contain two different metals, either two transition metals or a transition metal and a highly electropositive metal (Zn, Y, Sm ....), as well as numerous hydride ligands. Three different classes of synthetic procedures will be used for these heterometallic hydrides. In preliminary work the reduction of carbon dioxide by one heterobimetallic polyhydride has been observed. Since it can be argued that unpaired electron density should promote such hydrogenations from both a kinetic and a thermodynamic point of view, monomeric metallic polyhydrides with unpaired electrons will also be synthesized. Both monomeric and heterobimetallic polyhydrides will be characterized in terms of their dynamic processes ( e.g. by EPR spectroscopy ) and their chemical reactivity.