超卤素化合物作为复合氢化物储氢材料的构建单元
Superhalogens as Building Blocks of Complex Hydrides for Hydrogen Storage
摘要：
超卤素是指电子亲合势（EA）或垂直脱离能（VDE）超过卤素的物质。这些物质通常由中心正电性原子和负电性配体组成。超卤素配体可以进一步提高物种的EA或VDE，称为超卤素。在确定BH_4 ~-为超卤素离子后，我们用密度泛函理论研究了BH_4-x（BH_4）_x ~-（x = 1 ~ 4）超卤素阴离子及其Li配合物LiBH_4-x（BH_4）_x.这些阴离子的VDE大于BH 4-的VDE，其随外围BH 4基团数目（x）的增加而增加。LiBH_4-x（BH_4）_x复合物的储氢容量比LiBH_4高，但结合能比LiBH_4小。建立了LiBH_（4-x）（BH_（4））_x配合物的脱氢能与BH_（4-x）（BH_（4））_x-阴离子的VDE之间的线性关系。发现这些络合物对离解成LiBH 4和硼烷是化学稳定的。本研究不仅证明了超卤素在设计储氢新材料中的作用，而且也激发了实验人员合成LiBH 4-x（BH 4）x（x = 1 ~ 4）配合物。
英文摘要：
Superhalogens are species whose electron affinity (EA) or vertical detachment energy (VDE) exceed to those of halogen. These species typically consist of a central electropositive atom with electronegative ligands. The EA or VDE of species can be further increased by using superhalogen as ligands, which are termed as hyperhalogen. Having established BH4- as a superhalogen, we have studied BH4-x(BH4)x- (x = 1 to 4) hyperhalogen anions and their Li-complexes, LiBH4-x(BH4)x using density functional theory. The VDE of these anions is larger than that of BH4-, which increases with the increase in the number of peripheral BH4 moieties (x). The hydrogen storage capacity of LiBH4-x(BH4)x complexes is higher but binding energy is smaller than that of LiBH4, a typical complex hydride. The linear correlation between dehydrogenation energy of LiBH4-x(BH4)x complexes and VDE of BH4-x(BH4)x- anions is established. These complexes are found to be thermodynamically stable against dissociation into LiBH4 and borane. This study not only demonstrates the role of superhalogen in designing new materials for hydrogen storage, but also motivates experimentalists to synthesize LiBH4-x(BH4)x (x = 1 to 4) complexes.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
