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采用密度泛函理论方法(B3LYP和BP86)在6-311+G(d,p)基组水平上系统研究了新颖的铍-铍金属链夹心配合物D_(4d)[Be_n(C_4H_4)_2]~(2-)及[Be_n(C_4H_4)_2]Li_2(n=2~8)的几何结构、电子结构、成键特征及热力学稳定性。结果表明,具有交错式D4d对称性的D_(4d)[Be_n(C_4H_4)_2]~(2-)及[Be_n(C_4H_4)_2]Li_2为体系势能面上的真正极小。自然键轨道(NBO)、分子中的原子(AIM)及分子轨道分析表明,该系列夹心配合物中铍-铍间主要以共价键为主,而配体与铍-铍链之间则主要以离子键为主。核独立化学位移(NICS)分析表明配体在该系列配合物中具有π芳香性。稳定的夹心配合物锂盐[Be_n(C_4H_4)_2]Li_2(n=2~8)有望通过C4H4Li2/C5H-5配体交换反应进行制备,该系列配合物将进一步丰富多核夹心配合物研究领域。
The novel beryllium-beryllium metal chain sandwich complexes D_ (4d) [Be_n (C_4H_4) _2] have been systematically investigated by density functional theory (B3LYP and BP86) at 6-311 + G (d, Geometry, Electronic Structure, Bonding Characteristics and Thermodynamic Stability of ~ (2-) and [Be_n (C_4H_4) _2] Li_2 (n = 2-8) The results show that D_ (4d) [Be_n (C_4H_4) _2] ~ [Be_n (C_4H_4) _2] Li_2 with the symmetry of the interlaced D4d is the real minimum on the potential energy surface of the system. Natural bond orbital (NBO), molecular AIM and molecular orbital analysis indicate that the beryllium-beryllium in this series of sandwich complexes mainly consists of covalent bonds, while the ligands and beryllium-beryllium chains are mainly Ion-based. Nucleus Independent Chemical Shift (NICS) analysis showed that the ligand has π-aromaticity in the series of complexes. The stable sandwich complex lithium salt [Be_n (C_4H_4) _2] Li_2 (n = 2-8) is expected to be prepared by C4H4Li2 / C5H-5 ligand exchange reaction. This series of complexes will further enrich the research field of multi-core sandwich complexes.