碱土金属有机氢化物的研究进展

Research Progress of Molecular Alkaline-Earth Metal Hydrides

碱土金属(Mg,Ca,Sr,Ba)越来越引起大家的兴趣,这是由于它们价格低廉、无毒,可以替代许多有机催化和化学计量反应中昂贵的过渡金属.随着碱土金属离子半径的增大(Mg^2+<Ca^2+<Sr^2+<Ba^2+),碱土金属有机氢化物的离子性以及键长增加,键能降低,相应的金属氢化物更易发生Schlenk重排生成不溶无机盐[AeH2]∞(Ae=Mg,Ca,Sr,Ba),限制了其发展.近年来,人们通过选择合适的配体,合成并表征了一系列碱土金属有机氢化物,择优研究了它们与小分子的有机反应.碱土金属有机氢化物研究的最新进展将被详细介绍.

Alkaline-earth metals continue to receive growing interest,as they are used as low-cost and non-toxic alternatives to transition-metals in various organic transformations.As ionic character and bond lengths increase along the row in the order Mg^2+<Ca^2+<Sr^2+<Ba^2+,bond energies decrease along the same row,the corresponding metal hydrides are apt to the formation of insoluble metal hydrides[AeH2]∞(Ae=Mg,Ca,Sr,Ba)through Schlenk equilibrium in solution.Recently,a series of alkaline-earth metal hydrides stabilized by suitable ligands were discovered and characterized,and stoichiometric and catalytic reactions with small molecules were studied as well.In this paper,the recent progress in molecular alkaline-earth metal hydrides is reviewed.